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  • 1.
    Asadollahzadeh, Mohammadtaghi
    et al.
    Department of Pulp and Paper Technology, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
    Ghasemian, Ali
    Department of Pulp and Paper Technology, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
    Saraeian, Ahmadreza
    Department of Pulp and Paper Technology, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
    Resalati, Hossein
    Department of Wood and Paper Sciences, Sari University of Agricultural Sciences and Natural Resources, Sari, Iran.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Using spent sulfite liquor for valuable fungal biomass production by Aspergilus oryzae2017In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, no 4, p. 630-638Article in journal (Refereed)
    Abstract [en]

    The recent and increasing interest in bioconversion of lignocellulosic wastes into value-added products has led to extensive research on various microorganisms and substrates. In this study, filamentous fungus Aspergillus oryzae was cultivated on spent sulfite liquor (SSL) from a pulp mill. The process using an airlift bioreactor (3.5 L working volume) was successfully carried out in 48 h with an airflow of 0.85 vvm (volume air per volume culture per minute) at 35°C and pH 5.5. The cultivation results showed that the fungal biomass concentration was higher in more diluted SSL. The highest and lowest fungal biomass concentrations when spore inoculation was used were 10.2 and 6.5 g/l SSL, in diluted SSL to 60 and 80%, respectively. The range of crude protein and total fat of the fungal biomass was 0.44 – 0.48 and 0.04 – 0.11 g/g biomass dry weight, respectively. All essential amino acids were present in acceptable quantities in the fungal biomass. The results obtained in this study have practical implications in that the fungus A. oryzae could be used successfully to produce fungal biomass protein using spent sulfite liquor for animal feed.

  • 2.
    Brandberg, Tomas
    et al.
    University of Borås, School of Engineering.
    Lennartsson, Patrik
    University of Borås, School of Engineering.
    Fermenteringsteknik och andra mikroorganismer2012Conference paper (Other academic)
  • 3. Bátori, Veronika
    et al.
    Ferreira, Jorge A
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R
    University of Borås, Faculty of Textiles, Engineering and Business.
    Ethanol and Protein from Ethanol Plant By-Products Using Edible Fungi Neurospora intermedia and Aspergillus oryzae2015In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, Vol. 2015, no nov23Article in journal (Refereed)
    Abstract [en]

    Feasible biorefineries for production of second-generation ethanol are difficult to establish due to the process complexity. An alternative is to partially include the process in the first-generation plants. Whole stillage, a by-product from dry-mill ethanol processes from grains, is mostly composed of undegraded bran and lignocelluloses can be used as a potential substrate for production of ethanol and feed proteins. Ethanol production and the proteins from the stillage were investigated using the edible fungi Neurospora intermedia and Aspergillus oryzae, respectively. N. intermedia produced 4.7 g/L ethanol from the stillage and increased to 8.7 g/L by adding 1 FPU of cellulase/g suspended solids. Saccharomyces cerevisiae produced 0.4 and 5.1 g/L ethanol, respectively. Under a two-stage cultivation with both fungi, up to 7.6 g/L of ethanol and 5.8 g/L of biomass containing 42% (w/w) crude protein were obtained. Both fungi degraded complex substrates including arabinan, glucan, mannan, and xylan where reductions of 91, 73, 38, and 89% (w/v) were achieved, respectively. The inclusion of the current process can lead to the production of 44,000 m(3) of ethanol (22% improvement), around 12,000 tons of protein-rich biomass for animal feed, and energy savings considering a typical facility producing 200,000 m(3) ethanol/year.

  • 4.
    Bátori, Veronika
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Jabbari, Mostafa
    University of Borås, Faculty of Textiles, Engineering and Business.
    Åkesson, Dan
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Zamani, Akram
    University of Borås, Faculty of Textiles, Engineering and Business.
    Production of Pectin-Cellulose Biofilms: A New Approach for Citrus Waste Recycling2017In: International Journal of Polymer Science, ISSN 1687-9422, E-ISSN 1687-9430, Vol. 2017, p. 1-9, article id 9732329Article in journal (Refereed)
    Abstract [en]

    While citrus waste is abundantly generated, the disposal methods used today remain unsatisfactory: they can be deleterious for ruminants, can cause soil salinity, or are not economically feasible; yet citrus waste consists of various valuable polymers. This paper introduces a novel environmentally safe approach that utilizes citrus waste polymers as a biobased and biodegradable film, for example, for food packaging. Orange waste has been investigated for biofilm production, using the gelling ability of pectin and the strength of cellulosic fibres. A casting method was used to form a film from the previously washed, dried, and milled orange waste. Two film-drying methods, a laboratory oven and an incubator shaker, were compared. FE-SEM images confirmed a smoother film morphology when the incubator shaker was used for drying. The tensile strength of the films was 31.67 ± 4.21 and 34.76 ± 2.64 MPa, respectively, for the oven-dried and incubator-dried films, which is within the range of different commodity plastics. Additionally, biodegradability of the films was confirmed under anaerobic conditions. Films showed an opaque appearance with yellowish colour.

  • 5. FazeliNejad, Somayeh
    et al.
    Brandberg, Tomas
    University of Borås, School of Engineering.
    Lennartsson, Patrik R.
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Inhibitor Tolerance: A Comparison between Rhizopus sp. and Saccharomyces cerevisiae2013In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 8, no 4, p. 5524-5535Article in journal (Refereed)
    Abstract [en]

    Zygomycetes fungi are able to produce ethanol, and their biomass may hold a high market value, making them interesting microorganisms from a biorefinery perspective. In the present study, the inhibitor tolerance of the Zygomycetes fungus Rhizopus sp. was evaluated and compared with a flocculating strain of Saccharomyces cerevisiae. The inhibitors furfural, 5-hydroxymethylfurfural [HMF], acetic acid, and levulinic acid and the phenolic compounds catechol, guaiacol, and vanillin were applied in different combinations in a semi-synthetic medium. Glucose uptake and conversion of HMF in the presence of inhibitors were analyzed for the two organisms, and it appeared that the inhibitor resistances of Rhizopus sp. and S. cerevisiae were comparable. However, in the presence of catechol (0.165 g L-1), guaiacol (0.186 g L-1), and vanillin (0.30 g L-1), the glucose uptake by S. cerevisiae was only 3.5% of its uptake in a medium without inhibitors, while under equal conditions, Rhizopus sp. maintained 43% of its uninhibited glucose uptake.

  • 6.
    Fazelinejad, Somayeh
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Ferreira, Jorge A.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Brandberg, Tomas
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Fungal biomass and ethanol from lignocelluloses using Rhizopus pellets under simultaneous saccharification, filtration, and fermentation (SSFF)2016In: Biofuel Research Journal, ISSN 2292-8782, Vol. 9, p. 372-378Article in journal (Refereed)
    Abstract [en]

    The economic viability of the 2nd generation bioethanol production process cannot rely on a single product but on a biorefinery built around it. In this work, ethanol and fungal biomass (animal feed) were produced from acid-pretreated wheat straw slurry under an innovative simultaneous saccharification, fermentation, and filtration (SSFF) strategy. A membrane unit separated the solids from the liquid and the latter was converted to biomass or to both biomassand ethanol in the fermentation reactor containing Rhizopus sp. pellets. Biomass yields of up to 0.34 g/g based on the consumed monomeric sugars and acetic acid were achieved. A surplus of glucose in the feed resulted in ethanol production and reduced the biomass yield, whereas limiting glucose concentrations resulted in higher consumption of xylose and acetic acid. The specific growth rate, in the range of 0.013-0.015/h, did not appear to be influenced by the composition of the carbon source. Under anaerobic conditions, an ethanol yield of 0.40 g/g was obtained. The present strategy benefits fromthe easier separation of the biomass from the medium and the fungus ability to assimilate carbon residuals in comparison with when yeast is used. More specifically, it allows in-situ separation of insoluble solids leading to the production of pure fungal biomass as a value-added product. (C) 2016 BRTeam. All rights reserved.

  • 7.
    Ferreira, Jorge A.
    et al.
    University of Borås, School of Engineering.
    Lennartsson, Patrik R.
    University of Borås, School of Engineering.
    Edebo, Lars
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Zygomycetes-based biorefinery: Present status and future prospects2013In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 135, p. 523-532Article in journal (Refereed)
    Abstract [en]

    Fungi of the phylum Zygomycetes fulfil all requirements for being utilized as core catalysts in biorefineries, and would be useful in creating new sustainable products. Apart from the extended use of Zygomycetes in preparing fermented foods, industrial metabolites such as lactic acid, fumaric acid, and ethanol are produced from a vast array of feedstocks with the aid of Zygomycetes. These fungi produce enzymes that facilitate their assimilation of various complex substrates, e.g., starch, cellulose, phytic acid, and proteins, which is relevant from an industrial point of view. The enzymes produced are capable of catalyzing various reactions involved in biodiesel production, preparation of corticosteroid drugs, etc. Biomass produced with the aid of Zygomycetes consists of proteins with superior amino acid composition, but also lipids and chitosan. The biomass is presently being tested for animal feed purposes, such as fish feed, as well as for lipid extraction and chitosan production. Complete or partial employment of Zygomycetes in biorefining procedures is consequently attractive, and is expected to be implemented within a near future.

  • 8.
    Ferreira, Jorge A.
    et al.
    University of Borås, School of Engineering.
    Lennartsson, Patrik R.
    University of Borås, School of Engineering.
    Niklasson, Claes
    Lundin, Magnus
    University of Borås, School of Engineering.
    Edebo, Lars
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Spent sulphite liquor for cultivation of an edible Rhizopus sp.2012In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 7, no 1, p. 173-188Article in journal (Refereed)
    Abstract [en]

    Spent sulphite liquor, the major byproduct from the sulphite pulp production process, was diluted to 50% and used for production of an edible zygomycete Rhizopus sp. The focus was on production, yield, and composition of the fungal biomass composition. The fungus grew well at 20 to 40°C, but 32°C was found to be preferable compared to 20 and 40°C in terms of biomass production and yield (maximum of 0.16 g/g sugars), protein content (0.50-0.60 g/g), alkali-insoluble material (AIM) (ca 0.15 g/g), and glucosamine content (up to 0.30 g/g of AIM). During cultivation in a pilot airlift bioreactor, the yield increased as aeration was raised from 0.15 to 1.0 vvm, indicating a high demand for oxygen. After cultivation at 1.0 vvm for 84 h, high yield and production of biomass (up to 0.34 g/g sugars), protein (0.30-0.50 g/g), lipids (0.02-0.07 g/g), AIM (0.16-0.28 g/g), and glucosamine (0.22-0.32 g/g AIM) were obtained. The fungal biomass produced from spent sulphite liquor is presently being tested as a replacement for fishmeal in feed for fish aquaculture and seems to be a potential source of nutrients and for production of glucosamine.

  • 9.
    Ferreira, Jorge A.
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Airlift bioreactors for fish feed fungal biomass production using edible filamentous fungi2017Conference paper (Refereed)
    Abstract [en]

    Airlift bioreactors are generally considered to be better alternatives for cultivation of filamentous fungi in comparison to stirred-tank bioreactors or bubble columns bioreactors. The reason for the former includes fungal growth around all internal parts including impellers, baffles or pH, temperature and oxygen probes limiting mass transfer, whereas the latter is limited by air flow rates that can be applied before the system provides deficient mixing and so mass transfer rates. Spent sulphite liquor, a by-product from the paper pulp industry, was used for cultivation of edible Rhizopus sp., a strain isolated from Indonesian tempeh used as human food, using a 26 L airlift bioreactor. Increasing the aeration rate from 0.15 to 1 vvm led to increased biomass production (1 vs 7 g/L). The aeration rate was also found to influence fungal morphology and metabolite production during batch cultivation. Rhizopus sp. shifted from mycelial suspensions at 0.15 and 0.5 vvm to small compact pellets of regular size at 1 vvm. The production of ethanol and lactic acid, a proof of sub-optimal aeration conditions, was also reduced when increasing the aeration rate from 0.15 to 1 vvm. The produced biomass was found to be composed, on a dry weight basis, of 30-50% protein, 2-7% lipids, and 3-9% glucosamine. Considering the edible character of the fungus used as well as its biomass nutritional characteristics, there is a potential for its use as fishmeal replacement within the increasing aquaculture sector.

  • 10.
    Ferreira, Jorge A.
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Airlift bioreactors for fish feed fungal biomass production using edible filamentous fungi2017In: FFBiotech Symposium, University of Lille, Villeneuve d'Ascq, France, 2017Conference paper (Refereed)
  • 11.
    Ferreira, Jorge A.
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Improving the biorefinery "status" of ethanol plants with edible filamentous fungi2016Conference paper (Refereed)
  • 12.
    Ferreira, Jorge A
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Production of ethanol and biomass from thin stillage by Neurospora intermedia: A pilot study for process diversification2015In: Engineering in Life Sciences, ISSN 1618-0240, E-ISSN 1618-2863, Vol. 15, no 8, p. 751-759Article in journal (Refereed)
    Abstract [en]

    Dry mill ethanol processes produce ethanol and animal feed from whole grains,where the wastewater after the distillation and separation of solid materials is called“thin stillage.” In this work, similar production of ethanol (3.5 g/L) and biomass(5 g/L) from thin stillage was obtained during batch cultivation of the edible fungusNeurospora intermedia in a 2-m high airlift reactor and bubble column. The fungalbiomass, containing 50% w/w protein and 12% w/w lipids, was rich in essentialamino acids and omega-3 and -6 fatty acids. In a continuousmode of fermentation,dilution rates of up to 0.2 h−1 could be applied without cell washout in the bubblecolumn at 0.5 vvm. At 0.1 h−1, around 5 g/L of ethanol and 4 g/L of biomasscontaining ca. 50% w/w protein were produced. The fungus was able to assimilatesaccharides in the liquid fraction as well as sugar backbones such as xylan andarabinan in the solid fraction. The inclusion of the current process could potentiallylead to the production of 11 000 m3 of ethanol (5.5% improvement vs. normalindustrial process) and around 6300 tons of high-quality biomass for animal feed ata typical facility producing 200 000 m3 ethanol per year.

  • 13.
    Ferreira, Jorge A.
    et al.
    University of Borås, School of Engineering.
    Lennartsson, Patrik R.
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Production of Ethanol and Biomass from Thin Stillage Using Food-Grade Zygomycetes and Ascomycetes Filamentous Fungi2014In: Energies, Vol. 7, no 6, p. 3872-3885Article in journal (Refereed)
    Abstract [en]

    A starch-based ethanol facility producing 200,000 m3 ethanol/year also produces ca. 2 million m3 thin stillage, which can be used to improve the entire process. In this work, five food-grade filamentous fungi, including a Zygomycete and four Ascomycetes were successfully grown in thin stillage containing 9% solids. Cultivation with Neurospora intermedia led to the production of ca. 16 g·L−1 biomass containing 56% (w/w) crude protein, a reduction of 34% of the total solids, and 5 g·L−1 additional ethanol. In an industrial ethanol production process (200,000 m3 ethanol/year), this can potentially lead to the production of 11,000 m3 extra ethanol per year. Cultivation with Aspergillus oryzae resulted in 19 g·L−1 biomass containing 48% (w/w) crude protein and the highest reduction of the thin stillage glycerol (54%) among the Ascomycetes. Cultivation with Rhizopus sp. produced up to 15 g·L−1 biomass containing 55% (w/w) crude protein. The spent thin stillage had been reduced up to 85%, 68% and 21% regarding lactic acid, glycerol and total solids, respectively. Therefore, N. intermedia, in particular, has a high potential to improve the ethanol process via production of additional ethanol and high-quality biomass, which can be considered for animal feed applications such as for fish feed.

  • 14.
    Ferreira, Jorge A.
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Mahboubi, Amir
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Waste biorefineries using filamentous ascomycetes fungi: Present status and future prospects2016In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 215, no sept, p. 334-345Article in journal (Refereed)
    Abstract [en]

    Filamentous ascomycetes fungi have had important roles in natural cycles, and are already used industrially for e.g. supplying of citric, gluconic and itaconic acids as well as many enzymes. Faster human activities result in higher consumption of our resources and producing more wastes. Therefore, these fungi can be explored to use their capabilities to convert back wastes to resources. The present paper reviews the capabilities of these fungi in growing on various residuals, producing lignocellulose-degrading enzymes and production of organic acids, ethanol, pigments, etc. Particular attention has been on Aspergillus, Fusarium, Neurospora and Monascus genera. Since various species are used for production of human food, their biomass can be considered for feed applications and so biomass compositional characteristics as well as aspects related to culture in bioreactor are also provided. The review has been further complemented with future research avenues.[on SciFinder (R)]

  • 15.
    Ferreira, Jorge
    et al.
    University of Borås, School of Engineering.
    Lennartsson, Patrik
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Partial or complete inclusion of Zygomycetes fungi in biorefineries2013Conference paper (Other academic)
  • 16.
    Ferreira, Jorge
    et al.
    University of Borås, School of Engineering.
    Lennartsson, Patrik
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Thin stillage utilization by edible Ascomycetes and Zygomycetes for an improved ethanol2013Conference paper (Other academic)
  • 17.
    Ferreira, Jorge
    et al.
    University of Borås, School of Engineering.
    Lennartsson, Patrik
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Zygomycetes-based biorefineries2013Conference paper (Other academic)
  • 18. Gomez, P.F.
    et al.
    Lennartsson, P.R.
    University of Borås, School of Engineering.
    Persson, N.K.
    University of Borås, Swedish School of Textiles.
    Taherzadeh, M.J.
    University of Borås, School of Engineering.
    Heavy metal biosorption by Rhizopus sp. biomass immobilized on textiles2014In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 225, no 2Article in journal (Refereed)
    Abstract [en]

    Pollution by heavy metals is at present one of the major environmental concerns. In the present study, the potential of the filamentous zygomycete fungus Rhizopus sp. to absorb/adsorb metal ions from solution was investigated. With the aim to develop a feasible process, the fungus was immobilized on 10 different textile materials during the cultivation. All immobilized biosorbents reduced the Cu2+ concentrations initially from 20 to 3.1–5.6 mg/l within 150 min, with the exception of the biomass immobilized on wool, which reduced the Cu2+ level to 10.2 mg/l. The immobilized biomass (with the exception of wool) fitted well into a pseudo-second-order model. The uptake of copper showed a slight dependence on initial metal concentration. By reapplying immobilized Rhizopus sp. to a solution containing a low concentration of Cu2+ after going through a first step of biosorption, a decrease of the concentration to below 2 mg/l was accomplished, meeting the stipulated level for Cu2+ in human drinking water. Immobilization of fungal biomass in a cushion was also successfully applied in the biosorption process. The positive results obtained in a two-step biosorption indicate that a sequential arrangement could be the foundation for a commercial product.

  • 19. Ho Ky, Q. M.
    et al.
    Lennartsson, P.
    University of Borås, School of Engineering.
    Taherzadeh, M. J.
    University of Borås, School of Engineering.
    Dimorphism of Mucor indicus: different gene expressions between yeast-like and filamentous growth2013In: Minerva biotecnologica (Testo stampato), ISSN 1120-4826, E-ISSN 1827-160X, Vol. 25, no 1, p. 1-8Article in journal (Refereed)
    Abstract [en]

    Aim: Mucor indicus is a zygomycetes fungus with several advantages. Its ethanol yield from hexoses rivals that of Saccharomyces cerevisiae and it is capable of producing ethanol from xylose in limited aerobic conditions. It is also able to ferment dilute acid hydrolysate and is known to be dimorphic; able to grow in both filamentous and yeast-like modes. Methods: In this study, the difference between yeast-like and filamentous cells of M. indicus was investigated using modern polymerase chain reaction (PCR) techniques. Four mRNA sequences were detected with a higher expression in the filamentous growth form than in the yeast-like, by a factor of 1.3-4.2. One of the sequences was novel and three have been detected in another species of Mucor, M. circinelloides, coding for a chitin synthase, a proteasome and a sigma 70 factor. Results and conclusion: The novel sequence exhibited the largest difference in expression and was subjected to knock-down. However, it proved to be best suited for detection of emerging growth patterns, since the knock-down had little effect on the developing growth form. With the results of this study, an important step towards understanding the difference in the dimorphic behaviour exhibited by M. indicus, as well as other members of the genus Mucor, has been taken. Potentially it could also be used as one of the tools for the control of the dimorphic behaviour of M. indicus, and other species of the Mucor genus.

  • 20.
    Lennartsson, Patrik
    University of Borås, School of Engineering.
    Zygomycetes and cellulose residuals: hydrolysis, cultivation and applications2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Zygomycetes is a class of fungi living worldwide as saprobes, as part of mycorrhizae, and as parasites. Humans have used some zygomycetes for centuries in the production of traditional foods, e.g. Indonesian tempe. In the present thesis, the experimental focus was on two zygomycetes strains, Mucor indicus CCUG 22424 and Rhizopus sp. IT. One of the distinguishing features of M. indicus is its dimorphism. The different cell forms were influenced by the culturing conditions. After inoculation, when the initial spore concentration was high (6-8×106 spores/ml), yeast-like growth dominated under anaerobic conditions. With a smaller inoculum, yielding 1-2×105 spores/ml, and access to oxygen, filamentous forms dominated. Only negligible differences in ethanol yield (390-420 mg/g hexoses), productivity (3-5 g/l/h), and inhibitor tolerance were observed. Differential expressions of probably four genes were observed between the yeast-like and filamentous growth forms. Lignocelluloses are a suitable substrate for cultivating zygomycetes, as they occur in abundance, particularly since zygomycetes, unlike Saccharomyces cerevisiae, can utilise pentoses. Lignocelluloses require pretreatment to achieve efficient hydrolysis of the cellulose. N-methylmorpholine-N-oxide (NMMO) was tested for pretreatment of spruce and birch. Reducing wood chip size and/or prolonged pretreatment, promoted hydrolysis yield. Best yields were achieved from <2 mm chips and 5 h pretreatment. The hydrolysate was used for fermentation with M. indicus, resulting in 195 and 175 mg ethanol/g wood, and 103 and 86 mg fungal biomass/g wood, from spruce and birch respectively. Orange peel is another potential substrate. However, the hydrolysate contained 0.6 % (v/v) D-limonene, ten times higher than the concentration inhibiting S. cerevisiae. M. indicus was more resistant and successfully fermented the hydrolysate, producing 400 mg ethanol/g hexoses and 75 mg fungal biomass/g sugars. Both M. indicus and Rhizopus sp. grew in 1.0 % and 2.0 % D-limonene, although the latter was unable to grow in the hydrolysate. A third substrate was also used, spent sulphite liquor (SSL), which is a by-product from sulphite paper pulp mills. The SSL was diluted to 50 % and used for airlift cultivations of Rhizopus sp. In 1.0 vvm aeration, up to 340 mg biomass/g sugars was produced. Prolonged cultivations generally decreased the protein (from 500 to 300 mg/g) and lipid (from 70 to 20 mg/g) contents. In contrast, the cell wall fraction, measured as alkali-insoluble material (AIM), increased (160-280 mg/g), as did the glucosamine (GlcN) content (220-320 mg GlcN/g AIM). The produced fungal biomass could serve as animal feed, e.g. for fish.

  • 21.
    Lennartsson, Patrik
    et al.
    University of Borås, School of Engineering.
    Edebo, Lars
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Ethanol and valuable byproducts from lignocellulosic materials by zygomycetes2009Conference paper (Other academic)
  • 22.
    Lennartsson, Patrik
    et al.
    University of Borås, School of Engineering.
    Edebo, Lars
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Rhizopus2014In: Encyclopedia of Food Microbiology / [ed] C A Batt, M L Tortorello, Elsevier , 2014, p. 284-290Chapter in book (Refereed)
  • 23.
    Lennartsson, Patrik
    et al.
    University of Borås, School of Engineering.
    Erlandsson, Per
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Integration of the first and second generation bioethanol processes and the importance of by-products2014In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 165, p. 3-8Article in journal (Refereed)
    Abstract [en]

    Lignocellulosic ethanol has obstacles in the investment costs and uncertainties in the process. One solution is to integrate it with the running dry mills of ethanol from grains. However, the economy of these mills, which dominate the world market, are dependent on their by-products DDGS (Distiller’s Dried Grains and Solubles), sold as animal feed. The quality of DDGS therefore must not be negatively influenced by the integration. This puts restraints on the choice of pretreatment of lignocelluloses and utilizing the pentose sugars by food-grade microorganisms. The proposed solution is to use food related filamentous Zygomycetes and Ascomycetes fungi, and to produce fungal biomass as a high-grade animal feed from the residues after the distillation (stillage). This also has the potential to improve the first generation process by increasing the amount of the thin stillage directly sent back into the process, and by decreasing the evaporator based problems.

  • 24.
    Lennartsson, Patrik
    et al.
    University of Borås, School of Engineering.
    Karimi, Keikhosro
    University of Borås, School of Engineering.
    Edebo, Lars
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Effects of different growth forms of Mucor indicus on cultivation on dilute-acid lignocellulosic hydrolyzate, inhibitor tolerance, and cell wall composition2009In: Journal of Biotechnology, ISSN 0168-1656, E-ISSN 1873-4863, Vol. 143, no 4, p. 225-261Article in journal (Refereed)
    Abstract [en]

    The dimorphic fungus Mucor indicus was grown in different forms classified as purely filamentous, mostly filamentous, mostly yeast-like and purely yeast-like, and the relationship between morphology and metabolite production, inhibitor tolerance and the cell wall composition was investigated. Low concentrations of spores in the inoculum with subsequent aeration promoted filamentous growth, whereas higher spore concentrations and anaerobic conditions promoted yeast-like growth. Ethanol was the main metabolite with glycerol next under all conditions tested. The yields of ethanol from glucose were between 0.39 and 0.42 g g−1 with productivities of 3.2–5.0 g l−1 h−1. The ethanol productivity of mostly filamentous cells was increased from 3.9 to 5.0 g l−1 h−1 by the presence of oxygen, whereas aeration of purely yeast-like cells showed no such effect. All growth forms were able to tolerate 4.6 g l−1 furfural and 10 g l−1 acetic acid and assimilate the sugars, although with different consumption rates. The cell wall content of the fungus measured as alkali insoluble materials (AIM) of the purely yeast-like cells was 26% of the biomass, compared to 8% of the pure filaments. However, the chitosan concentration of the filaments was 29% of the AIM, compared to 6% of the yeast-like cells.

  • 25.
    Lennartsson, Patrik
    et al.
    University of Borås, School of Engineering.
    Niklasson, Claes
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    A pilot study on lignocelluloses to ethanol and fish feed using NMMO pretreatment and cultivation with Zygomycetes in an airlift reactor2011In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 102, no 6, p. 4425-4432Article in journal (Refereed)
    Abstract [en]

    A complete process for the production of bioethanol and fungal biomass from spruce and birch was investigated. The process included milling, pretreatment with N-methylmorpholine-N-oxide (NMMO), washing of the pretreated wood, enzymatic hydrolysis, and cultivation of the zygomycetes fungi Mucor indicus. Investigated factors included wood chip size (0.5-16 mm), pretreatment time (1-5 h), and scale of the process from bench-scale to 2 m high airlift reactor. Best hydrolysis yields were achieved from wood chips below 2 mm after 5 h of pretreatment. Ethanol yields (mg/g wood) of 195 and 128 for spruce, and 175 and 136 for birch were achieved from bench-scale and airlift, respectively. Fungal biomass yields (mg/g wood) of 103 and 70 for spruce, and 86 and 66 for birch from bench scale and airlift respectively were simultaneously achieved. NMMO pretreatment and cultivation with M. indicus appear to be a good alternative for ethanol production from birch and spruce.

  • 26.
    Lennartsson, Patrik R.
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Ferreira, Jorge A.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lundin, Magnus
    University of Borås, Faculty of Textiles, Engineering and Business.
    Gmoser, Rebecca
    University of Borås, Faculty of Textiles, Engineering and Business.
    Pigment Production by the Edible Filamentous Fungus Neurospora Intermedia2018In: Fermentation, ISSN 2311-5637, Vol. 4, no 11, p. 1-15Article in journal (Refereed)
    Abstract [en]

    The production of pigments by edible filamentous fungi is gaining attention as a result of the increased interest in natural sources with added functionality in the food, feed, cosmetic, pharmaceutical and textile industries. The filamentous fungus Neurospora intermedia, used for production of the Indonesian food “oncom”, is one potential source of pigments. The objective of the study was to evaluate the fungus’ pigment production. The joint effect from different factors (carbon and nitrogen source, ZnCl2, MgCl2 and MnCl2) on pigment production by N. intermedia is reported for the first time. The scale-up to 4.5 L bubble column bioreactors was also performed to investigate the effect of pH and aeration. Pigment production of the fungus was successfully manipulated by varying several factors. The results showed that the formation of pigments was strongly influenced by light, carbon, pH, the co-factor Zn2+ and first- to fourth-order interactions between factors. The highest pigmentation (1.19 ± 0.08 mg carotenoids/g dry weight biomass) was achieved in a bubble column reactor. This study provides important insights into pigmentation of this biotechnologically important fungus and lays a foundation for future utilizations of N. intermedia for pigment production. 

  • 27.
    Lennartsson, Patrik
    et al.
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Zygomycetes fungi: A core of Biorefineries2013Conference paper (Other academic)
  • 28.
    Lennartsson, Patrik
    et al.
    University of Borås, School of Engineering.
    Ylitervo, Päivi
    University of Borås, School of Engineering.
    Larsson, Christer
    Edebo, Lars
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Growth tolerance of Zygomycetes Mucor indicus in orange peel hydrolysate without detoxification2012In: Process Biochemistry, ISSN 1359-5113, E-ISSN 1873-3298, Vol. 47, no 5, p. 836-842Article in journal (Refereed)
    Abstract [en]

    The capability of two zygomycetes strains, Mucor indicus and an isolate from tempeh (Rhizopus sp.), to grow on orange peel hydrolysate and their tolerance to its antimicrobial activity, was investigated. Both fungi, in particular M. indicus, tolerated up to 2% d-limonene in semi-synthetic media during cultivation in shake flasks, under aerobic as well as anaerobic conditions. The tolerance of M. indicus was also tested in a bioreactor, giving rise to varying results in the presence of 2% limonene. Furthermore, both strains were capable of consuming galacturonic acid, the main monomer of pectin, under aerobic conditions when no other carbon source was present. The orange peel hydrolysate was based on 12% (dry w/v) orange peels, containing d-limonene at a concentration of 0.6% (v/v), which no other microorganism has been reported to be able to ferment. However, the hydrolysate was utilised by M. indicus under aerobic conditions, resulting in production of 410 and 400 mg ethanol/g hexoses and 57 and 75 mg fungal biomass/g sugars from cultivations in shake flasks and a bioreactor, respectively. Rhizopus sp., however, was slow to germinate aerobically, and neither of the zygomycetes was able to consistently germinate in orange peel hydrolysate, under anaerobic conditions. The zygomycetes strains used in the present study demonstrated a relatively high resistance to the antimicrobial compounds present in orange peel hydrolysate, and they were capable of producing ethanol and biomass in the presence of limonene, particularly when cultivated with air supply.

  • 29.
    Lennartsson, P.R.
    et al.
    University of Borås, School of Engineering.
    Karimi, K.
    University of Borås, School of Engineering.
    Edebo, L.
    Taherzadeh, M.J.
    University of Borås, School of Engineering.
    Ethanol production by dimorphic fungus Mucor indicus2008Conference paper (Refereed)
  • 30.
    Mahboubi, Amir
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Ferreira, Jorge A.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Production of Fungal Biomass for Feed, Fatty Acids, and Glycerol by Aspergillus oryzae from Fat-Rich Dairy Substrates2017In: Fermentation, ISSN 2311-5637, Vol. 3, no 4Article in journal (Other academic)
    Abstract [en]

    Dairy waste is a complex mixture of nutrients requiring an integrated strategy for valorization into various products. The present work adds insights into the conversion of fat-rich dairy products into biomass, glycerol, and fatty acids via submerged cultivation with edible filamentous fungi. The pH influenced fat degradation, where Aspergillus oryzae lipase was more active at neutral than acidic pH (17 g/L vs. 0.5 g/L of released glycerol); the same trend was found during cultivation in crème fraiche (12 g/L vs. 1.7 g/L of released glycerol). In addition to glycerol, as a result of fat degradation, up to 3.6 and 4.5 g/L of myristic and palmitic acid, respectively, were released during A. oryzae growth in cream. The fungus was also able to grow in media containing 16 g/L of lactic acid, a common contaminant of dairy waste, being beneficial to naturally increase the initial acidic pH and trigger fat degradation. Considering that lactose consumption is suppressed in fat-rich media, a two-stage cultivation for conversion of dairy waste is also proposed in this work. Such an approach would provide biomass for possibly feed or human consumption, fatty acids, and an effluent of low organic matter tackling environmental and social problems associated with the dairy sector.

  • 31.
    Mahboubi, Amir
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business. Biotechnology.
    Ferreira, Jorge A.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Value-added products from dairy waste using edible fungi2017In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 59, p. 518-525Article in journal (Refereed)
  • 32. Nair, R. B.
    et al.
    Gmoser, Rebecca
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Does the second messenger cAMP have a more complex role in controlling filamentous fungal morphology and metabolite production?2018In: MicrobiologyOpen, ISSN 2045-8827, E-ISSN 2045-8827Article in journal (Refereed)
  • 33.
    Nair, Ramkumar B
    et al.
    University of Borås, School of Engineering.
    Brandberg, Thomas
    Lennartsson, Patrik R
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J
    University of Borås, School of Engineering.
    Dilute phosphoric acid pretreatment of wheat straw for ethanol production using edible fungi2014Conference paper (Refereed)
  • 34.
    Nair, Ramkumar B
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Eh-Hser Nay, Theimya
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business. Biotechnology.
    Waste Bread Valorization Using Edible Filamentous Fungi2017Conference paper (Refereed)
    Abstract [en]

    The present study is the first of its kind to use industrial waste bread for ethanol and food-grade filamentous fungal biomass production, with an ‘integrated-biorefinery’ approach for the existing wheat-based ethanol facilities. Four different food-grade fungi such as Neurospora intermedia, Aspergillus oryzae, belonging to ascomycetes and Mucor indicus, Rhizopus oryzae, belonging to zygomycetes, were screened. Initial screening for fungal cultures (without external enzyme saccharification) showed an ethanol yield maximum of 47.8 ±1.1 to 67.3 ±2.1, and 38.7 ±1.1 to 67.7±1.8 mg per g dry substrate loading from whole-grain bread and white-bread respectively, post the enzymatic liquefaction. Scale-up of the N. intermedia fermentation achieved using bench scale airlift reactor showed an ethanol yield maximum of 91.6 ±2.1 and 87.5 ±1.9 mg per g dry substrate loading for whole-grain bread and white-bread respectively.

  • 35.
    Nair, Ramkumar B
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Kabir, Maryam M.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Sárvári Horváth, Ilona
    University of Borås, Faculty of Textiles, Engineering and Business.
    Integrated Process for Ethanol, Biogas, and Edible Filamentous Fungi-Based Animal Feed Production from Dilute Phosphoric Acid-Pretreated Wheat Straw2017In: Applied Biochemistry and Biotechnology, ISSN 0273-2289, E-ISSN 1559-0291, p. 1-15Article in journal (Refereed)
    Abstract [en]

    Integration of wheat straw for a biorefinery-based energy generation process by producing ethanol and biogas together with the production of high-protein fungal biomass (suitable for feed application) was the main focus of the present study. An edible ascomycete fungal strain Neurospora intermedia was used for the ethanol fermentation and subsequent biomass production from dilute phosphoric acid (0.7 to 1.2% w/v) pretreated wheat straw. At optimum pretreatment conditions, an ethanol yield of 84 to 90% of the theoretical maximum, based on glucan content of substrate straw, was observed from fungal fermentation post the enzymatic hydrolysis process. The biogas production from the pretreated straw slurry showed an improved methane yield potential up to 162% increase, as compared to that of the untreated straw. Additional biogas production, using the syrup, a waste stream obtained post the ethanol fermentation, resulted in a combined total energy output of 15.8 MJ/kg wheat straw. Moreover, using thin stillage (a waste stream from the first-generation wheat-based ethanol process) as a co-substrate to the biogas process resulted in an additional increase by about 14 to 27% in the total energy output as compared to using only wheat straw-based substrates. .[on SciFinder (R)]

  • 36.
    Nair, Ramkumar B
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Kalif, Mahdi
    University of Borås, Faculty of Textiles, Engineering and Business.
    Ferreira, Jorge A.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Mild-temperature dilute acid pretreatment for integration of first and second generation ethanol processes2017In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 245, p. 145-151Article in journal (Refereed)
    Abstract [en]

    The use of hot-water (100 °C) from the 1st generation ethanol plants for mild-temperature lignocellulose pretreatment can possibly cut down the operational (energy) cost of 2nd generation ethanol process, in an integrated model. Dilute-sulfuric and -phosphoric acid pretreatment at 100 °C was carried out for wheat bran and whole-stillage fibers. Pretreatment time and acid type influenced the release of sugars from wheat bran, while acid-concentration was found significant for whole-stillage fibers. Pretreatment led up-to 300% improvement in the glucose yield compared to only-enzymatically treated substrates. The pretreated substrates were 191–344% and 115–300% richer in lignin and glucan, respectively. Fermentation using Neurospora intermedia, showed 81% and 91% ethanol yields from wheat bran and stillage-fibers, respectively. Sawdust proved to be a highly recalcitrant substrate for mild-temperature pretreatment with only 22% glucose yield. Both wheat bran and whole-stillage are potential substrates for pretreatment using waste heat from the 1st generation process for 2nd generation ethanol.

  • 37.
    Nair, Ramkumar B.
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lundin, Magnus
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Optimizing dilute phosphoric acid pretreatment of wheat straw in the laboratory and in a demonstration plant for ethanol and edible fungal biomass production using Neurospora intermedia.2016In: Journal of chemical technology and biotechnology (1986), ISSN 0268-2575, E-ISSN 1097-4660Article in journal (Refereed)
    Abstract [en]

    BACKGROUND : A method is described that uses dil. phosphoric acid for wheat straw pretreatment and subsequent ethanol and fungal biomass prodn. with the edible fungus Neurospora intermedia. Dil. phosphoric acid pretreatment of wheat straw was optimized at a lab. scale, and the results were validated in a biorefinery demonstration plant for the first time. The various conditions for the dil. acid pretreatment include such factors as phosphoric acid concns. (0.5-3.0% w/v), temp. (150-210 °C), and reaction time (5-20 min). RESULTS : The optimal pretreatment conditions were detd. as an acid concn. of 1.75% (w/v) at a temp. of 190 °C for 15 min, based on the max. enzymic digestibility with the min. inhibitor release. The efficiency of enzymic polysaccharide hydrolysis was 36% for untreated straw and 86% for straw pretreated with dil. phosphoric acid. Scale up of the pretreatment at a biorefinery demonstration plant improved the process, with the subsequent efficiency of polysaccharide hydrolysis being 95% of the theor. max. Ethanol fermn. of enzymically hydrolyzed wheat straw using N. intermedia showed an improvement in the ethanol yield from 29% (with untreated straw) to 94% (with dil. phosphoric acid pretreated straw) of the theor. max. CONCLUSION : This study opens up an alternative strategy for the efficient use of wheat straw for the prodn. of ethanol and edible fungal biomass in existing wheat-to-ethanol plants.

  • 38.
    Nair, Ramkumar B
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Ravula, Vamsikrishna
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Neurospora intermedia pellets for enhanced ethanol and fungal biomass production from wheat straw2017In: Proceedings of 39th Symposium on Biotechnology for Fuels and Chemicals, 2017Conference paper (Refereed)
    Abstract [en]

    Recent studies at our research group have described an ‘integrated-biorefinery’ model for the existing 1st generation wheat-based ethanol facilities, by using edible filamentous fungus, Neurospora intermedia. The process focuses on the production of 2nd generation ethanol together with fungal biomass (for animal or aquaculture feed applications) from wheat straw. A final ethanol yield of 94% (theoretical maximum based on substrate glucan content) was obtained with N. intermedia fermentation in dilute phosphoric acid pretreated (0.7%w/v acid, 7min at 201±4°C) and enzymatically hydrolyzed (10FPU cellulase/g substrate) straw. Fungal cultivation in liquid straw hydrolysate resulted in a maximum of 3.71±0.11g/L dry fungal biomass. Considering the industrial significance of the fungal process, attempts were made to manipulate N. intermedia to grow as pellet forms in the straw hydrolysate, for the first time. Of the various culture conditions screened, stable pellet morphology was obtained at pH 3.0 to 5.5, resulting in uniform pellets with size ranging from 2.5 to 4.25mm. Fermentation using N. intermedia pellets in the liquid straw hydrolysate, resulted in about 31% increase in the ethanol yield, with an improved glucose assimilation by the pellets (82% reduction) as opposed to filamentous forms (51% reduction), at similar culture conditions. The growth of fungal pellets in presence of inhibitors (at different concentrations of acetic acid and furfural) resulted in about 11% to 45% increase in ethanol production as compared to filamentous forms, at similar growth conditions in the liquid straw hydrolysate. Detailed results on N. intermedia pelletization in liquid straw hydrolysate will be discussed in this presentation.

  • 39.
    Nair, Ramkumar
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business. Swedish Centre for Resource Recovery.
    Ferreira, Jorge
    University of Borås, Faculty of Textiles, Engineering and Business. Swedish Centre for Resource Recovery.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business. Swedish Centre for Resource Recovery.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Evaluating dilute phosphoric acid pretreated wheat bran for ethanol and edible fungal biomass production: A pilot study2015Conference paper (Refereed)
    Abstract [en]

    Purpose of the work:

    The present study reports the application of using dilute phosphoric acid for pretreatment of wheat branbiomass and its subsequent use as an ethanol fermentation substrate for edible fungi, Neurospora intermedia inbench scale (4.5L) and pilot airlift (26L) reactors.

    Approach:

    The optimized pretreatment conditions to release maximum sugar and minimum inhibitor concentrations weredetermined using a statistically modelled experimental setup. The dilute acid pretreatment was scaled up withthe validation of lab results in a biorefinery demo plant (BDP) at Svensk Etanolkemi AB – SEKAB (Örnsköldsvik,Sweden). The structural and physiological changes in the bran biomass during the pretreatment process werealso studied. Bench scale and pilot scale enzymatic hydrolysis of the pretreated biomass and subsequent ethanolfermentation using edible ascomycetes fungi, N. intermedia were studied using airlift reactors.

    Scientific innovation and relevance:

    With the use of dilute phosphoric acid, the study put forth an alternative strategy to the current use of relativelystronger acids for lignocellulosic biomass pretreatment. The potential use of acid pretreated lignocellulosicbiomass (wheat bran) as an ethanol feedstock, together with the edible fungal cultivation is a first of its kindapproach towards a wider ‘biorefinery’ concept. Improving the co-product (DDGS) quality and ethanol yield inthe existing wheat based ethanol facilities, whereby enhancing the overall ethanol production economics formsthe ultimate aim of the study.

    Results:

    Wheat bran was subjected to dilute acid pretreatment at varying acid concentrations (0.5–3.0% w/v),temperature (150–210◦C), and reaction time (5–20 min). The interaction of multiple factors showed theoptimum pretreatment conditions at acid concentration of 1.75% (w/v), at 190◦C for 10 min. A maximum totalpolysaccharide yield of 0.27 ± 0.01 g/g dry biomass loading, corresponding to 66% of the theoretical maximumwas observed. The effect of the dilute acid pretreatment on the functional groups of the wheat bran cellulosewas determined with 78% reduction in the cellulose crystallinity index. Enzymatic hydrolysis of pretreated slurryfrom the demo plant showed 85% total theoretical yield of polysaccharides. Compared to the untreated branbiomass, an increase of 51% was observed in the ethanol yield following pretreatment, with a total ethanol yieldof 95% theoretical maximum. Similar results were also observed on scaling up the reaction volume in a benchscale (4.5L) and pilot scale (26L) airlift reactors, which will also be presented in detail.

    Conclusions:

    The present work brings out the potential of using phosphoric acid as an efficient pretreatment agent addressingthe long existing problems associated with the sulfur contamination of the feed. Additional advantages relatedto the nutritional enrichment of DDGS (at the existing wheat based ethanol facility), with the use of edibleascomycetes fungi were also achieved. However, techno-economical analyses are required to determine theactual industrial feasibility of the process.

  • 40.
    Nair, Ramkumar
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Bioethanol production from agricultural and municipal waste2016In: Current Developments in Biotechnology and Bioengineering: Solid Waste Management / [ed] Wong, J.; Tyagi, R.D.; Pandey, A., USA: Elsevier, 2016, 1, p. 157-190Chapter in book (Refereed)
    Abstract [en]

    Bioethanol, one of the most promising technological advancements of the century, has been widely acclaimed for being produced from diversified origins. Production of bioethanol from food grains (as in Brazil or the United States) is however frequently criticized in the food vs. fuel debate. Several research studies across the globe, investigating the potential use of various renewable resources (such as waste biomass), have resulted in the emergence of second and/or third generation bioethanol processes. This chapter attempts to consolidate various aspects of bioethanol production from solid waste biomass. Waste biomass of lignocellulosic and starch-based origin, such as municipal solid waste, industrial waste (waste paper or coffee residues), livestock manure, and agricultural waste (wood biomass and agricultural crop residues), were reviewed for their potential to produce ethanol. This chapter describes the feedstock prospects, process technologies, and the current research and industrial developments.

  • 41.
    Nair, Ramkumar
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad
    University of Borås, Faculty of Textiles, Engineering and Business.
    Mycelial pellet formation by edible ascomycete filamentous fungi, Neurospora intermedia2016In: AMB Express, ISSN 2191-0855, E-ISSN 2191-0855, Vol. 6, no 31, article id 10.1186/s13568-016-0203-2Article in journal (Refereed)
    Abstract [en]

    Pellet formation of filamentous fungi in submerged culture is an imperative topic of fermentation research. In this study, we report for the first time the growth of filamentous ascomycete fungus,Neurospora intermedia in its mycelial pellet form. In submerged culture, the growth morphology of the fungus was successfully manipulated into growing as pellets by modifying various cultivation conditions. Factors such as pH (2.0–10.0), agitation rate (100–150 rpm), carbon source (glucose, arabinose, sucrose, and galactose), the presence of additive agents (glycerol and calcium chloride) and trace metals were investigated for their effect on the pellet formation. Of the various factors screened, uniform pellets were formed only at pH range 3.0–4.0, signifying it as the most influential factor for N. intermedia pellet formation. The average pellet size ranged from 2.38 ± 0.12 to 2.86 ± 0.38 mm. The pellet formation remained unaffected by the inoculum type used and its size showed an inverse correlation with the agitation rate of the culture. Efficient glucose utilization was observed with fungal pellets, as opposed to the freely suspended mycelium, proving its viability for fast- fermentation processes. Scale up of the pelletization process was also carried out in bench-scale airlift and bubble column reactors (4.5 L).

  • 42.
    Nair, Ramkumar
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business. Swedish Centre for Resource Recovery.
    Lundin, Magnus
    University of Borås, Faculty of Textiles, Engineering and Business. Swedish Centre for Resource Recovery.
    Brandberg, Tomas
    Lennartsson, Patrik
    University of Borås, Faculty of Textiles, Engineering and Business. Swedish Centre for Resource Recovery.
    Taherzadeh, Mohammad J
    University of Borås.
    Dilute phosphoric acid pretreatment of wheat bran for enzymatic hydrolysis and subsequent ethanol production by edible fungi Neurospora intermedia.2015In: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 69, p. 314-323Article in journal (Refereed)
    Abstract [en]

    The use of an underutilized and abundant lignocellulosic feedstock residue, wheat bran, was studied for ethanol prodn. using dil. phosphoric acid pretreatment followed by fermn. using edible fungi Neurospora intermedia. Wheat bran was subjected to dil. acid pretreatment at varying acid concns. (0.5-3.0% w/v), temp. (150-210 °C), and reaction time (5-20 min). The interaction of multiple factors showed the optimum pretreatment conditions at acid concn. of 1.75% (w/v), at 190 °C for 10 min. The max. total polysaccharide yield of 0.27 ± 0.01 g/g dry biomass loading, corresponding to 66% of the theor. max. was obsd. Subsequent fermn. with N. intermedia showed 85% of the theor. max. ethanol yield from the untreated bran glucose. The effect of the dil. acid pretreatment on the functional groups of the wheat bran cellulose was detd. with 78% redn. in the cellulose crystallinity index. The validation of the dil. phosphoric acid pretreatment in a demo plant is also reported for the first time. Enzymic hydrolysis of pretreated slurry from the demo plant showed 85% total theor. yield of polysaccharides. Compared to the untreated bran biomass, an increase of 51% was obsd. in the ethanol yield following pretreatment, with a total ethanol yield of 95% theor. max. Higher yield of ethanol is also attributed to the xylose fermenting capability of the fungi. [on SciFinder(R)]

  • 43. Nyman, Jonas
    et al.
    Lacintra, Gomes
    Westman, Johan
    University of Borås, School of Engineering.
    Berglin, M
    Lundin, Magnus
    University of Borås, School of Engineering.
    Lennartsson, Patrik
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad
    University of Borås, School of Engineering.
    Pellet formation of zygomycetes and immobilization of yeast2013In: New Biotechnology, ISSN 1871-6784, E-ISSN 1876-4347, Vol. 30, no 5, p. 516-522Article in journal (Refereed)
    Abstract [en]

    Pelleted growth provides many advantages for filamentous fungi, including decreased broth viscosity, improved aeration, stirring, and heat transfer. Thus, the factors influencing the probability of pellet formation of Rhizopus sp. in a defined medium was investigated using a multifactorial experimental design. Temperature, agitation intensity, Ca2+-concentration, pH, and solid cellulose particles, each had a significant effect on pelletization. Tween 80, spore concentration, and liquid volume were not found to have a significant effect. All of the effects were additive; no interactions were significant. The results were used to create a simple defined medium inducing pelletization, which was used for immobilization of a flocculating strain of Saccharomyces cerevisiae in the zygomycetes pellets. A flor-forming S. cerevisiae strain was also immobilized, while a non-flocculating strain colonized the pellets but was not immobilized. No adverse effects were detected as a result of the close proximity between the filamentous fungus and the yeast, which potentially allows for co-fermentation with S. cerevisiae immobilized in pellets of zygomycetes

  • 44. Osadolor, Osagie A.
    et al.
    Nair, Ramkumar B
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Empirical and experimental determination of the kinetics of pellet growth in filamentous fungi: A case study using Neurospora intermedia.2017In: Biochemical engineering journal, ISSN 1369-703X, E-ISSN 1873-295X, Vol. 124, p. 115-121Article in journal (Refereed)
    Abstract [en]

    Pellet morphol. formation by filamentous fungi has gained a lot of attention because of its multiple benefits such as the ease of sepn. and smaller bioreactor vol. requirement. Most reported kinetics studies on fungal pellet growth are centered on aeration, despite the exptl. results pointing to the importance of other factors such as pH, substrates and product concn. etc., influencing the pellet formation. Hence a kinetic study on the effect of multiple factors such as aeration, substrate and product concn. and pH was done in this paper using Neurospora intermedia as a model organism, whose ability to form mycelial pellets was recently reported. The max. growth rate of the pellets under uninhibited conditions at its optimal growth pH was 0.318 h-1. The pellets were found to be inhibited by high product (ethanol) concn. with no growth occurring at 70 g L-1 and above. High substrate concn. favored the formation of loose fur-like fluffy pellets. The specific oxygen uptake rate of the pellets was between 0.27-0.9 mmol-O2 g-biomass-1h-1 depending on the pellet av. diam. The results from this kinetic study can be used for bioreactor design, operations and optimization of fermn. processes utilizing N. intermedia. [on SciFinder(R)]

  • 45.
    Osadolor, Osagie Alex
    University of Borås, Faculty of Textiles, Engineering and Business.
    Nair, Ramkumar B
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Effect of media rheology and bioreactor hydrodynamics on filamentous fungi fermentation of lignocellulosic and starch-based substrates under pseudoplastic flow conditions2018In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 263, p. 250-257Article in journal (Refereed)
    Abstract [en]

    The aim of this work was to study how media rheology and bioreactor hydrodynamics would influence fermentation of lignocellulosic and starch-based substrates under pseudoplastic flow conditions. This was investigated using hydrolyzed wheat straw, wheat-based thin stillage and filamentous fungi as inoculum in bubble column, airlift and horizontal hybrid tubular/bubble column (textile bioreactor) bioreactors. The rheological models showed that the consistency index was dependent on biomass growth (R2 0.99) while the flow behavior index depended on biomass growth and suspended solid (R2 0.99). Oxygen transfer rate above 0.356 mmol-O2/L/h was needed for growing fungi with a cube-root growth rate constant of 0.03 g1/3/L1/3/h. At 1.4 VVM aeration the textile bioreactor performed better than others with minimal foaming, yields of 0.22 ± 0.01 g/g and 0.47 ± 0.01 g/g for ethanol and biomass, substrate consumption rate of 0.38 g/L/h. Operating the bioreactors with air-flowrate to cross-sectional area ratio of 8.75 × 10−3 (m3/s/m2) or more led to sustained foaming.

  • 46.
    Osadolor, Osagie Alex
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad
    University of Borås, Faculty of Textiles, Engineering and Business.
    Textile bioreactor a possible solution to reducing ethanol fermentation cost2016In: Bioprocess and Bio Therapeutics, 2016Conference paper (Refereed)
    Abstract [en]

    There is growing concern on bioethanol application as a transportation fuel because of the current low price of crude oil. To reduce the ethanol fermentation cost, how ethanol bioreactors can be designed to offer process flexibility, reduced investment cost, optimal productivity and more than 1 h-1 dilution rates without washout was investigated. A bioreactor made with textile as its backbone material of construction was designed to anaerobically utilize flocculating yeast for ethanol production without using mixing devices like aerators, spargers and stirrers. A mixing system was developed that used the flocculating yeast in the form of a fluidized bed in the bioreactor, and the conditions needed to maintain the fluidized bed in the bioreactor were determined. Recirculation flow rate and utilization of the mixing system were used as process variables for fermentation experiments. It was found that it is possible to use the fluidized mixing system in the bioreactor at dilution rate of 1.2 h‑1 without washout. Mass transfer limitations associated with mixing when using flocculating yeast was resolved even at low recirculation mixing rate of 0.0016 VVM. Specific ethanol productivity of 0.29 ± 0.01 g-ethanol/g-biomass/h with complete sucrose consumption was attained. Using the bioreactor with flocculating yeast can reduce the fermentation investment cost of a 100,000 m3/y ethanol plant by 37 %. 

  • 47.
    Osadolor, Osagie Alex
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik
    Taherzadeh, Mohammad
    Textile bioreactor for ethanol production2015In: Bioreactor Design and Engineering, 2015Conference paper (Refereed)
    Abstract [en]

    Problem statement: To achieve optimal production, optimal process conditions needs to be used. However, this increases the cost of fermentation. How can a bioreactor be developed to produce at optimal levels under suboptimal conditions with a substantial reduction of the fermentation cost. Purpose: Designing and developing the bioreactor features like temperature control, mixing, aeration, charging in and transfer out, and appropriate biomass contacting pattern within the textile bioreactor, with the overall goal of optimal productivity with substantial savings in the fermentation cost. Methods: A 30 L prototype of the textile bioreactor, with a working volume of 25 L was worked on. Temperature was controlled by a PVC tubing and a thermostatic circulator. Mixing and aeration control was achieved by using silicone tubing. Fermentation experiments with yeast as biomass were performed using temperature (30 °C to room temperature of 22 °C), mixing (with and without mixing), and flowrates (1.5 L/min – 0.04 L/min) as process variables. Results: No bacteria contamination was observed in all experiments performed. Optimum fermentation time of 15 h and ethanol yield of 0.48 ± 0.01 g/g sucrose was gotten from experiments performed at 30 °C with mixing and a flowrate of 0.92 L/min. Experiments done without mixing and at room temperature had the longest fermentation time of 42 h and an ethanol yield of 0.49 ± 0.02 g/g sucrose. Temperature was found to be the process variable with the highest impact on the fermentation rate. The specific productivity reduced from 1.34 ± 0.02 g L −1 h −1 under optimal temperature and mixing conditions to 0.53 ± 0.02 g L −1 h −1 at room temperature without mixing. The same optimal ethanol production rate can be gotten under sub optimal production conditions. At room temperature and without mixing, using a bioreactor volume 2.53 times the volume of that used with optimal temperature and mixing would give the same optimal productivity. This can reduce the fermentation investment cost of a 100,000 m3/y ethanol production facility by 26 %. While using a 1300 m3 textile bioreactor in place of a stainless steel reactor in this plant can reduce the fermentation cost by 19 %. Conclusion: 26 % investment cost reduction, and optimal ethanol production can be achieved under sub optimal conditions by using appropriate volume of the textile bioreactor. 

  • 48.
    Osadolor, Osagie Alex
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Development of Novel Textile Bioreactor for Anaerobic Utilization of Flocculating Yeast for Ethanol Production2015In: Fermentation, ISSN 2311-5637, Vol. 1, no 1, p. 98-112, article id 101566Article in journal (Refereed)
    Abstract [en]

    Process development, cheaper bioreactor cost, and faster fermentation rate can aid in reducing the cost of fermentation. In this article, these ideas were combined in developing a previously introduced textile bioreactor for ethanol production. The bioreactor was developed to utilize flocculating yeast for ethanol production under anaerobic conditions. A mixing system, which works without aerators, spargers, or impellers, but utilizes the liquid content in the bioreactor for suspending the flocculating yeast to form a fluidized bed, was developed and examined. It could be used with dilution rates greater than 1.0 h−1 with less possibility of washout. The flow conditions required to begin and maintain a fluidized bed were determined. Fermentation experiments with flow rate and utilization of the mixing system as process variables were carried out. The results showed enhanced mass transfer as evidenced by faster fermentation rates on experiments with complete sucrose utilization after 36 h, even at 30 times lesser flow rate.

  • 49.
    Osadolor, Osagie Alex
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lundin, Magnus
    University of Borås, Faculty of Textiles, Engineering and Business.
    Lennartsson, Patrik
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad
    University of Borås, Faculty of Textiles, Engineering and Business.
    Membrane stress analysis of collapsible tanks andbioreactorsIn: Biochemical engineering journal, ISSN 1369-703X, E-ISSN 1873-295XArticle in journal (Refereed)
    Abstract [en]

    Collapsible tanks, vessels or bioreactors are finding increasing usage in small/medium scaleprocesses because they offer flexibility and lower cost. However, if they are to be used atlarge scale, they need to be shown capable of handling the physical stress exerted on them.Because of their nonconventional shape and non-uniform pressure distribution, thin shellanalysis cannot be used in calculating their stress. Defining curvature in terms of pressureaddressed these challenges. Using curvature and numerical analysis, the membrane stress incollapsible tanks designed as bioreactors of volumes between 100-1000 m3 were calculated.When the liquid/gas height and static pressure are known, an equation for calculating tensionper length was developed. An equation that could calculate the liquid height from thebioreactor’s volume, dimensions and working capacity was generated. The equation gavevalues of liquid height with a maximum deviation of 3% from that calculated by curvatureanalysis. The stress values from the liquid height and tension equations had a maximumdeviation of 6% from those calculated by curvature analysis. The calculated tensile stress in a1000 m3 collapsible tank was 14.2 MPa. From these calculations, materials that optimize bothcost and safety can be selected when designing collapsible tanks.

  • 50.
    Pietrzak, Witold
    et al.
    Wroclaw University of Environmental and Life Sciences.
    Kawa-Rygielska, Joanna
    Wroclaw University of Environmental and Life Sciences.
    Krol, Barbara
    Wroclaw University of Environmental and Life Sciences.
    Lennartsson, Patrik R.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Ethanol, feed components and fungal biomass production from field bean (Vicia faba var. equina) seeds in an integrated process2016In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 216, p. 69-76Article in journal (Refereed)
    Abstract [en]

    The use of field beans, a non-food leguminous crop, was studied for ethanol, feed components and fungal biomass production. The seeds were hydrolyzed using enzymes or with combination of acid (H3PO4) and alkaline (Ca(OH)2) pretreatment and enzymatic hydrolysis. Fermentation by Saccharomyces cerevisiae, with or without removal of suspended solids, yielded 38.3-42.5gL(-1) ethanol (71.3-79.2% efficiency). The filtration residues contained ca. 247-326gkg(-1) crude protein, 10.6-15.5% acid detergent fiber and 19.9-29.1% neutral detergent fiber. They were enriched in phenolics (by up to 93.4%) and depleted in condensed tannin (by up to 59.3%) in comparison to the raw material. The thin stillages were used for cultivation of edible fungus Neurospora intermedia which produced 8.5-15.9gL(-1) ethanol and 4.8-16.2gL(-1) biomass containing over 62% protein. The mass balances showed that fermentation of unfiltered mashes was more efficient yielding up to 195.9gkg(-1) ethanol and 84.4% of protein recovery.[on SciFinder (R)]

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