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Nair, Ramkumar B
Alternative names
Publications (10 of 16) Show all publications
Osadolor, O. A. (2018). Effect of media rheology and bioreactor hydrodynamics on filamentous fungi fermentation of lignocellulosic and starch-based substrates under pseudoplastic flow conditions. Bioresource Technology, 263, 250-257
Open this publication in new window or tab >>Effect of media rheology and bioreactor hydrodynamics on filamentous fungi fermentation of lignocellulosic and starch-based substrates under pseudoplastic flow conditions
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2018 (English)In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 263, p. 250-257Article in journal (Refereed) Published
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.

Keywords
Foaming Oxygen transfer rate, Rheology model, Fungi growth kinetics, Bioreactor hydrodynamics
National Category
Chemical Process Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-14345 (URN)10.1016/j.biortech.2018.04.093 (DOI)000439317100030 ()2-s2.0-85046700875 (Scopus ID)
Available from: 2018-06-21 Created: 2018-06-21 Last updated: 2018-11-29Bibliographically approved
Jabbari, M., Osadolor, O. A., Nair, R. B. & Taherzadeh, M. J. (2017). All-polyamide composite coated-fabric as an alternative material of construction for textile-bioreactors (TBRs). Energies, 10(11)
Open this publication in new window or tab >>All-polyamide composite coated-fabric as an alternative material of construction for textile-bioreactors (TBRs)
2017 (English)In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, no 11Article in journal (Refereed) Published
Abstract [en]

All-polyamide composite coated-fabric (APCCF) was used as an alternative material for the construction of textile-bioreactors (TBRs), which are prepared as a replacement of the traditional stainless steel bioreactors (SSBRs) or concrete-based bioreactors. The material characteristics, as well as the fermentation process performance of the APCCF-TBR, was compared with a TBR made using the polyvinyl chloride (PVC)-coated polyester fabric (PVCCF). The TBRs were used for the anaerobic fermentation process using baker's yeast; and, for aerobic fermentation process using filamentous fungi, primarily by using waste streams from ethanol industries as the substrates. The results from the fermentation experiments were similar with those that were obtained from the cultivations that were carried out in conventional bioreactors. The techno-economic analysis conducted using a 5000 m3 APCCF-TBR for a typical fermentation facility would lead to a reduction of the annual production cost of the plant by 128,000,000 when compared to similar processes in SSBR. The comparative analyses (including mechanical and morphological studies, density measurements, thermal stability, ageing, and techno-economic analyses) revealed that the APCCF is a better candidate for the material of construction of the TBR. As the APCCF is a 100% recyclable single-polymer composite, which was prepared from Nylon 66 textile production-line waste, it could be considered as an environmentally sustainable product. 

Place, publisher, year, edition, pages
MDPI AG, 2017
Keywords
All-polyamide coated-fabric, Edible filamentous fungi cultivation, Nylon 66, Polyvinyl chloride (PVC) coated-textile, Single-polymer composite, Techno-economic analysis, Textile bioreactor, Waste management, Yeast fermentation
National Category
Industrial Biotechnology
Identifiers
urn:nbn:se:hb:diva-14814 (URN)10.3390/en10111928 (DOI)000417046500247 ()2-s2.0-85035113895 (Scopus ID)19961073 (ISSN) (ISBN)
Available from: 2018-08-02 Created: 2018-08-02 Last updated: 2018-12-01
Osadolor, O. A., Nair, R. B., Lennartsson, P. R. & Taherzadeh, M. J. (2017). Empirical and experimental determination of the kinetics of pellet growth in filamentous fungi: A case study using Neurospora intermedia.. Biochemical engineering journal, 124, 115-121
Open this publication in new window or tab >>Empirical and experimental determination of the kinetics of pellet growth in filamentous fungi: A case study using Neurospora intermedia.
2017 (English)In: Biochemical engineering journal, ISSN 1369-703X, E-ISSN 1873-295X, Vol. 124, p. 115-121Article in journal (Refereed) Published
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)]

Place, publisher, year, edition, pages
Elsevier B.V., 2017
Keywords
Neurospora intermedia, Fungi pellets, Kinetic parameters, Growth inhibition, Fermentation
National Category
Industrial Biotechnology
Identifiers
urn:nbn:se:hb:diva-12533 (URN)10.1016/j.bej.2017.05.012 (DOI)000404199100014 ()2-s2.0-85019359697 (Scopus ID)
Note

Copyright (C) 2017 American Chemical Society (ACS). All Rights Reserved.; CAPLUS AN 2017:831336(Journal; Online Computer File)

Available from: 2017-08-27 Created: 2017-08-27 Last updated: 2017-09-29Bibliographically approved
Nair, R. B., Kabir, M. M., Lennartsson, P. R., Taherzadeh, M. J. & Sárvári Horváth, I. (2017). Integrated Process for Ethanol, Biogas, and Edible Filamentous Fungi-Based Animal Feed Production from Dilute Phosphoric Acid-Pretreated Wheat Straw. Applied Biochemistry and Biotechnology, 1-15
Open this publication in new window or tab >>Integrated Process for Ethanol, Biogas, and Edible Filamentous Fungi-Based Animal Feed Production from Dilute Phosphoric Acid-Pretreated Wheat Straw
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2017 (English)In: Applied Biochemistry and Biotechnology, ISSN 0273-2289, E-ISSN 1559-0291, p. 1-15Article in journal (Refereed) Published
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)]

Keywords
bioethanol, biogas, dilute acid pretreatment, filamentous fungi, integration, n. intermedia, wheat straw
National Category
Industrial Biotechnology
Identifiers
urn:nbn:se:hb:diva-12539 (URN)10.1007/s12010-017-2525-1 (DOI)000419607700005 ()2-s2.0-85020404803 (Scopus ID)
Note

Copyright (C) 2017 U.S. National Library of Medicine.; MEDLINE AN 2018665916(Journal; Article; (JOURNAL ARTICLE))

Available from: 2017-08-27 Created: 2017-08-27 Last updated: 2018-11-30Bibliographically approved
Nair, R. B. (2017). Integration of first and second generation bioethanol processes using edible filamentous fungus Neurospora intermedia. (Doctoral dissertation). Borås: Högskolan i Borås
Open this publication in new window or tab >>Integration of first and second generation bioethanol processes using edible filamentous fungus Neurospora intermedia
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Establishing a commercial, lignocellulose-based, second-generation ethanol process has received several decades of attention by both researchers and industry. However, a fully economically viable process still remains a long-term goal. The main bottleneck to this achievement is the recalcitrance of lignocellulosic feedstocks, although there are several other factors, such as the huge investment required for second-generation ethanol facilities. An intelligent alternative solution discussed in this thesis is an integrated approach using firstgeneration ethanol plants for second-generation processes. Wheat is the major feedstock for first-generation ethanol in Europe; therefore, wheat-based lignocellulose waste, such as wheat straw, bran, and whole stillage fiber (a waste stream from first-generation wheat-based ethanol plants) was the primary focus of the integration model in this thesis. Since the major share of first-generation ethanol plant economics focuses on the animal feed DDGS (Distillers’ dried gains with solubles), the integration of lignocellulose should be designed in order to maintain DDGS quality. An ethanol-producing edible filamentous fungus, Neurospora intermedia, a potential protein source in DDGS, was considered for use as the fermenting microbe. The morphological and physiological aspects of this fungus were studied in the thesis, leading to the first report of fungal pellet development.

An alternative approach of using dilute phosphoric acid to pretreat lignocellulose, as it does not negatively affect fungal growth or DDGS quality, was demonstrated in both the laboratory and on a 1m3 pilot scale. Furthermore, the process of hydrolysis of pretreated lignocelluloses and subsequent N. intermedia fermentation on lignocellulose hydrolysate was also optimized in the laboratory and scaled up to 1 m3 using an in-house pilot-scale airlift bioreactor. Fungal fermentation on acid-pretreated and enzyme-hydrolyzed wheat bran, straw and whole stillage fiber resulted in a final ethanol yield of 95%, 94% and 91% of the theoretical maximum based on the glucan content of the substrate, respectively. Integrating the first- and second-generation processes using thin stillage (a waste stream from first-generation wheat-based ethanol plants) enhanced the fungal growth on straw hydrolysate, avoiding the need for supplementing with extra nutrients.

Based on the results obtained from this thesis work, a new model for integrated first- and second-generation ethanol using edible filamentous fungi processes that also adds value to animal feed (DDGS) was developed.

Place, publisher, year, edition, pages
Borås: Högskolan i Borås, 2017
Series
Skrifter från Högskolan i Borås, ISSN 0280-381X ; 82
Keywords
First- and second-generation bioethanol, Integration, Neurospora intermedia, Edible filamentous fungi, Wheat straw, Wheat bran, Whole stillage fiber
National Category
Natural Sciences
Identifiers
urn:nbn:se:hb:diva-12436 (URN)978-91-88269-51-5 (ISBN)978-91-88269-52-2 (ISBN)
Available from: 2017-09-13 Created: 2017-07-24 Last updated: 2017-09-22Bibliographically approved
Nair, R. B., Kalif, M., Ferreira, J. A., Taherzadeh, M. J. & Lennartsson, P. R. (2017). Mild-temperature dilute acid pretreatment for integration of first and second generation ethanol processes. Bioresource Technology, 245, 145-151
Open this publication in new window or tab >>Mild-temperature dilute acid pretreatment for integration of first and second generation ethanol processes
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2017 (English)In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 245, p. 145-151Article in journal (Refereed) Published
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.

Keywords
Bioethanol, Edible filamentous fungi, Lignocelluloses, Mild temperature pretreatment, Neurospora intermedia
National Category
Bioenergy Bioprocess Technology Chemical Process Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-12931 (URN)10.1016/j.biortech.2017.08.125 (DOI)000412443500018 ()2-s2.0-85028936794 (Scopus ID)
Available from: 2017-10-26 Created: 2017-10-26 Last updated: 2018-08-20Bibliographically approved
Nair, R. B., Ravula, V., Lennartsson, P. R. & Taherzadeh, M. J. (2017). Neurospora intermedia pellets for enhanced ethanol and fungal biomass production from wheat straw. In: Proceedings of 39th Symposium on Biotechnology for Fuels and Chemicals: . Paper presented at 39th Symposium on Biotechnology for Fuels and Chemicals, San Francisco USA, May 1-4, 2017.
Open this publication in new window or tab >>Neurospora intermedia pellets for enhanced ethanol and fungal biomass production from wheat straw
2017 (English)In: Proceedings of 39th Symposium on Biotechnology for Fuels and Chemicals, 2017Conference paper, Poster (with or without abstract) (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.

Keywords
Neurospora intermedia, Fungal pellets, wheat straw, Bioethanol, Edible filamentous fungi
National Category
Chemical Process Engineering Bioprocess Technology Bioenergy
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-12921 (URN)
Conference
39th Symposium on Biotechnology for Fuels and Chemicals, San Francisco USA, May 1-4, 2017
Available from: 2017-10-25 Created: 2017-10-25 Last updated: 2017-12-13Bibliographically approved
Nair, R. B. & Taherzadeh, M. J. (2017). Process for edible filamentous fungal cultivation and its integration in conventional sugar to ethanol production.. India . (IN201621018552A) .
Open this publication in new window or tab >>Process for edible filamentous fungal cultivation and its integration in conventional sugar to ethanol production.
2017 (English)Patent (Other (popular science, discussion, etc.))
Abstract [en]

The present invention relates to a process for edible fungal cultivation by employing vinasse or spent wash of first generation ethanol prodn. as a substrate. More particularly, the present invention relates to a process for edible fungal cultivation in the form of pellets. [on SciFinder(R)]

Place, publisher, year, edition, pages
India ., 2017
National Category
Industrial Biotechnology
Identifiers
urn:nbn:se:hb:diva-12536 (URN)
Note

Copyright (C) 2017 American Chemical Society (ACS). All Rights Reserved.; CAPLUS AN 2017:48517(Patent)

Available from: 2017-08-27 Created: 2017-08-27 Last updated: 2017-09-22Bibliographically approved
Nair, R. B., Eh-Hser Nay, T., Lennartsson, P. R. & Taherzadeh, M. J. (2017). Waste Bread Valorization Using Edible Filamentous Fungi. In: : . Paper presented at EUBCE 2017 – 25th European Biomass Conference and Exhibition, Stockholm Sweden, June 12-15, 2017.
Open this publication in new window or tab >>Waste Bread Valorization Using Edible Filamentous Fungi
2017 (English)Conference paper, Poster (with or without abstract) (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.

Keywords
Integrated-biorefinery, Edible filamentous fungi, Bread waste, Ethanol, Animal feed
National Category
Bioprocess Technology Bioenergy
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-12922 (URN)
Conference
EUBCE 2017 – 25th European Biomass Conference and Exhibition, Stockholm Sweden, June 12-15, 2017
Available from: 2017-10-25 Created: 2017-10-25 Last updated: 2017-12-14Bibliographically approved
Nair, R., Lennartsson, P. R. & Taherzadeh, M. J. (2016). Bioethanol production from agricultural and municipal waste (1ed.). In: Wong, J.; Tyagi, R.D.; Pandey, A. (Ed.), Current Developments in Biotechnology and Bioengineering: Solid Waste Management: (pp. 157-190). USA: Elsevier
Open this publication in new window or tab >>Bioethanol production from agricultural and municipal waste
2016 (English)In: 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.

Place, publisher, year, edition, pages
USA: Elsevier, 2016 Edition: 1
National Category
Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-11689 (URN)2-s2.0-85010899631 (Scopus ID)
Available from: 2017-01-09 Created: 2017-01-09 Last updated: 2018-11-28Bibliographically approved
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