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Sárvári Horváth, IlonaORCID iD iconorcid.org/0000-0002-1456-1840
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Publications (10 of 81) Show all publications
Yangin-Gomec, C., Agnihotri, S., Ylitervo, P. & Sárvári Horváth, I. (2023). Assessment of Microbial Diversity during Thermophilic Anaerobic Co-Digestion for an Effective Valorization of Food Waste and Wheat Straw. Energies, 16(1), Article ID 15.
Open this publication in new window or tab >>Assessment of Microbial Diversity during Thermophilic Anaerobic Co-Digestion for an Effective Valorization of Food Waste and Wheat Straw
2023 (English)In: Energies, E-ISSN 1996-1073, Vol. 16, no 1, article id 15Article in journal (Refereed) Published
Abstract [en]

In this study, predominant bacterial and archaeal populations and their roles during anaerobic mono-digestion of food waste (FW) and co-digestion of FW with straw pellets (SP) at thermophilic temperature (53 ± 1 °C) were assessed by Next Generation Sequencing (NGS) analysis at organic loading rates (OLRs) of 3.0 and 7.0 gVS/L/d. Depending on the seed; results revealed that Firmicutes, Bacteroidetes, and Proteobacteria were, respectively the most prevalent bacterial phyla at both OLRs investigated. On the other hand, Euryarchaeota was dominated by methanogens playing crucial role in biogas production and correlated mainly with the activities of Methanobacteria and Methanomicrobia at class level. Acetoclastic Methanosaetae was the predominant genus at OLR = 3.0 gVS/L/d; however, shared the same predominance with hydrogenotrophic methanogens Methanospirillium at the highest OLR. Although no clear effect in response to straw addition at OLR of 3.0 gVS/L/d could be seen in terms of methanogenic archaea at genus level, hydrogenotrophic methanogens revealed some shift from Methanobacterium to Methanospirillium at higher OLR. Nevertheless, no prominent microbial shift in the presence of wheat straw at increased OLR was likely due to adapted inoculation at start-up which was also demonstrated by relatively stable biogas yields during co-digestion.

Place, publisher, year, edition, pages
MDPI, 2023
Keywords
biogas yield, co-substrate, food waste, methanogens, next generation sequencing
National Category
Other Industrial Biotechnology
Identifiers
urn:nbn:se:hb:diva-29248 (URN)10.3390/en16010055 (DOI)000909041900001 ()2-s2.0-85145776617 (Scopus ID)
Available from: 2023-01-11 Created: 2023-01-11 Last updated: 2024-01-16
Yangin-Gomec, C., Sárvári Horváth, I. & Martín, C. (2023). Energy Production from Biomass Valorization. Energies, 16(11), Article ID 4300.
Open this publication in new window or tab >>Energy Production from Biomass Valorization
2023 (English)In: Energies, E-ISSN 1996-1073, Vol. 16, no 11, article id 4300Article in journal, Editorial material (Refereed) Published
National Category
Other Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-30282 (URN)10.3390/en16114300 (DOI)001006598100001 ()2-s2.0-85161646325 (Scopus ID)
Available from: 2023-08-14 Created: 2023-08-14 Last updated: 2024-02-01Bibliographically approved
Yarsur, E., Sárvári Horváth, I. & Yangin Gömeç, Ç. (2023). Methane yield of paper industry waste in the presence of two compounds from alcohol and aldehyde groups during thermophilic anaerobic digestion. In: Environmental Research and Technology: . Paper presented at 6th EurAsia Waste Management Symposium, 24-26, October, 2022 (pp. 54-59). Yildiz Technical University (1)
Open this publication in new window or tab >>Methane yield of paper industry waste in the presence of two compounds from alcohol and aldehyde groups during thermophilic anaerobic digestion
2023 (English)In: Environmental Research and Technology, Yildiz Technical University , 2023, no 1, p. 54-59Conference paper, Published paper (Refereed)
Abstract [en]

In this study, effect of two chemical compounds (i.e., 1-octanol and hexanal) respectively from the alcohol and aldehyde groups on thermophilic (55±2 °C) anaerobic process digesting the waste produced at a paper industry was investigated. In this scope, possible inhibition was monitored by the cumulative methane (CH4) yields in the batch reactors digesting the paper waste as the feedstock at concentrations of 0.005%, 0.05%, and 0.5% for each compound. Comparing the effects of the two different groups with the control reactor having only the paper waste as the substrate, the results revealed that adding 1-octanol and hexanal up to 0.05% concentrations had some synergistic effect on biogas yield (i.e., from 3% to 12% enhancement). Accordingly, the highest methane yields were 550 and 567 mL/g-VSfed, respectively on average in the presence of 1-octanol and hexanal at a concentration of 0.05% while the cumulative methane yield was observed as 490 mL/g-VSfed for the control reactor. With the exception of 1-octanol at 0.5%, adding both compounds at each investigated concentration was beneficial for the digestion in the batch process. Therefore, the selected alcohol and aldehyde sources did not cause the expected detrimental effect on the methanogens even at the maximum amounts added in this study. Nevertheless, since the effect of the chemical compounds on methane generation has been generally concentration-dependent, the toxic effects of 1-octanol and hexanal would be better observed at higher concentrations (>0.5%), especially when their threshold levels are exceeded in anaerobic reactors digesting paper wastes. 

Place, publisher, year, edition, pages
Yildiz Technical University, 2023
Keywords
1-octanol, Biogas, Hexanal, Inhibition, Lignocellulose
National Category
Other Industrial Biotechnology
Identifiers
urn:nbn:se:hb:diva-30285 (URN)10.35208/ert.1212911 (DOI)2-s2.0-85156223018 (Scopus ID)
Conference
6th EurAsia Waste Management Symposium, 24-26, October, 2022
Available from: 2023-08-14 Created: 2023-08-14 Last updated: 2024-02-01Bibliographically approved
Akintunde, M., Adebayo-Tayo, B. C., Ishola, M. M., Zamani, A. & Sárvári Horváth, I. (2022). Bacterial Cellulose Production from agricultural Residues by two Komagataeibacter sp. Strains. Bioengineered, 13(4), 10010-10025
Open this publication in new window or tab >>Bacterial Cellulose Production from agricultural Residues by two Komagataeibacter sp. Strains
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2022 (English)In: Bioengineered, ISSN 2165-5979, E-ISSN 2165-5987, Vol. 13, no 4, p. 10010-10025Article in journal (Refereed) Published
Abstract [en]

Agricultural residues are constantly increasing with increased farming processes, and improper disposal is detrimental to the environment. Majority of these waste residues are rich in lignocellulose, which makes them suitable substrate for bacterial fermentation in the production of valueadded products. In this study, bacterial cellulose (BC), a purer and better form of cellulose, was produced by two Komagataeibacter sp. isolated from rotten banana and kombucha drink using corncob (CC) and sugarcane bagasse (SCB) enzymatic hydrolyzate, under different fermentation conditions, that is, static, continuous, and intermittent agitation. The physicochemical and mechanical properties of the BC films were then investigated by Fourier Transformed Infrared Spectroscopy (FTIR), Thermogravimetry analysis, Field Emission Scanning Electron Microscopy (FESEM), and Dynamic mechanical analysis. Agitation gave a higher BC yield, with Komagataeibacter sp. CCUG73629 producing BC from CC with a dry weight of 1.6 g/L and 1.4 g/L under continuous and intermittent agitation, respectively, compared with that of 0.9 g/L in HS medium. While BC yield of dry weight up to 1.2 g/L was obtained from SCB by Komagataeibacter sp. CCUG73630 under continuous agitation compared to that of 0.3 g/L in HS medium. FTIR analysis showed BC bands associated with cellulose I, with high thermal stability. The FE-SEM analysis showed that BC fibers were highly ordered and densely packed. Although the BC produced by both strains showed similar physicochemical and morphological properties, the BC produced by the Komagataeibacter sp. CCUG73630 in CC under intermittent agitation had the best modulus of elasticity, 10.8 GPa and tensile strength, 70.9 MPa. [GRAPHICS]

National Category
Biochemistry and Molecular Biology Composite Science and Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-27795 (URN)10.1080/21655979.2022.2062970 (DOI)000783506100001 ()2-s2.0-85128138635 (Scopus ID)
Available from: 2022-04-28 Created: 2022-04-28 Last updated: 2023-01-18
Pinheiro, V. E., Wainaina, S., Polizeli, M. D. & Sárvári Horváth, I. (2021). Anaerobic digestion of cornmeal: the effect of crude enzyme extract and co-digestion with cow manure. Biofuels, Bioproducts and Biorefining
Open this publication in new window or tab >>Anaerobic digestion of cornmeal: the effect of crude enzyme extract and co-digestion with cow manure
2021 (English)In: Biofuels, Bioproducts and Biorefining, ISSN 1932-104X, E-ISSN 1932-1031Article in journal (Refereed) Published
Abstract [en]

This study examined the effect of a crude enzyme extract, containing mainly starch-degrading enzymes, on cornmeal (Zea mays) hydrolysis. This was followed by an investigation of the effect of enzymatic treatment for the anaerobic digestion of this biomass. Cornmeal and cow manure were also co-digested, and both batch and semi-continuous experiments were performed. The enzymatic pretreatment of cornmeal resulted in a yield of 65 ± 5% reducing sugars, with 1:10 w/v (grams of dry substrate per mililiters of enzyme extract) enzyme load at 45 °C for 48 h. There was an 8% enhancement of methane production observed during the batch assays, both when cornmeal hydrolysate was digested and when enzymes were added directly to the digester. Synergetic effects were found when co-digesting cornmeal and cow manure, leading to higher methane yield (280 NmL gVS–1) than that (200 NmL gVS–1) calculated based on the methane potential of the individual substrates. Regarding long-term effects, the laboratory-scale semi-continuous experiments also demonstrated that the co-digestion of cornmeal and cow manure (1:1 volatile solid (VS) basis) led to a stable process reaching an organic loading rate of 3 g VS L day–1 and achieving a daily methane production of 1280.12 ± 99.4 NmL CH4/day. However, when cornmeal was investigated in mono-digestion, and the enzyme extract was directly added during semi-continuous digestion of cornmeal, volatile fatty acid (VFA) accumulation was observed, leading to a decrease in pH, and no significant enhancement of the conversion into methane was observed. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Place, publisher, year, edition, pages
John Wiley and Sons Ltd, 2021
Keywords
anaerobic digestion, co-digestion, cornmeal, cow manure, enzymatic hydrolysis, Chemical industry, Fertilizers, Manures, Methane, Stability criteria, Substrates, Volatile fatty acids, Codigestion, Crude enzymes, Degrading enzymes, Enzymatic treatments, Methane production, Semi-continuous, Volatile solid, Zea mays
National Category
Bioenergy Chemical Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-26974 (URN)10.1002/bbb.2303 (DOI)000710190400001 ()2-s2.0-85117602713 (Scopus ID)
Available from: 2021-12-02 Created: 2021-12-02 Last updated: 2022-09-14Bibliographically approved
Foereid, B., Szocs, J., Patinvoh, R. J. & Sárvári Horváth, I. (2021). Effect of anaerobic digestion of manure before application to soil – benefor nitrogen utilisation?. International Journal of Recycling of Organic Waste in Agriculture, 10(1), 89-99
Open this publication in new window or tab >>Effect of anaerobic digestion of manure before application to soil – benefor nitrogen utilisation?
2021 (English)In: International Journal of Recycling of Organic Waste in Agriculture, ISSN 2195-3228, E-ISSN 2251-7715, Vol. 10, no 1, p. 89-99Article in journal (Refereed) Published
Abstract [en]

Purpose Anaerobic digestion produces renewable energy, biogas, from organic residues, but also digestate, a valuable organic fertiliser. Previous studies have indicated that digestate contains ample plant available nitrogen (N), but there are also concerns about greenhouse gas (GHG) emissions after application of digestates to soil. The aim of this study was to compare digestate and undigested feedstock for fertiliser effect as well as greenhouse gas emissions during the next season. Method Digestate and its feedstock, manure, were compared as N fertilisers for wheat. Mixing digestate with biochar before application was also tested. After harvest, soil samples were frozen and dried. Then GHG emissions immediately after a re-wetting of dry soil and after thawing of frozen soil were measured to determine emissions after a non-growing season (dry or cold). Results All N in digestate was plant available, while there was no significant N fertiliser effect of the undigested manure. N2 O emissions were higher after a dry season than after freezing, but the undigested manure showed higher emissions during thawing than those detected during thawing of soils from any of the other treatments. Conclusion Anaerobic digestion makes N available to plants, and when residues with much N that is not plant available the first season are used, the risk of N2 O emission next spring is high. © 2021, Islamic Azad University. All rights reserved.

Place, publisher, year, edition, pages
Islamic Azad University, 2021
Keywords
Biochar, Digestate, Nitrogen Fertiliser value, Nitrous oxide, Re-wetting, Thawing, anaerobic digestion, carbon emission, greenhouse gas, manure, rewetting, soil nitrogen
National Category
Agricultural Science
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-26008 (URN)10.30486/IJROWA.2020.1897538.1055 (DOI)000741372600008 ()2-s2.0-85102999674 (Scopus ID)
Available from: 2021-07-08 Created: 2021-07-08 Last updated: 2024-02-01Bibliographically approved
Pinheiro, V. E., Sárvári Horváth, I., Lundin, M. & Polizeli, M. D. (2021). Screening and cocktail optimization using experimental mixture design: enzymatic saccharification as a biological pretreatment strategy. Biofuels, Bioproducts and Biorefining
Open this publication in new window or tab >>Screening and cocktail optimization using experimental mixture design: enzymatic saccharification as a biological pretreatment strategy
2021 (English)In: Biofuels, Bioproducts and Biorefining, ISSN 1932-104X, E-ISSN 1932-1031Article in journal (Refereed) Epub ahead of print
Abstract [en]

Biofuels contribute environment-friendly, renewable energy, minimizing dependence on fossil energy. The pretreatment of biomass is a practical step that accelerates and facilitates the hydrolysis of complex materials. This work aimed to screen, select, and study cocktail formulations for biomass hydrolysis, where the enzymes were provided both from a commercial source (Trichoderma reesei, Novozymes®) and through the cultivation of Aspergillus brasiliensis and Aspergillus tamarii Kita. Experimental mixture designs were used to optimize the enzymatic conversion of substrates into simple sugars. A crude extract rich in amylase (AAB) had a significant favorable influence on cornmeal hydrolysis by maximizing the yield of reducing sugars (RS) (173 μmol mL–1). Celluclast™, rich in cellulase, significantly affected the hydrolysis of banana peel, maximizing the RS yield (175 μmol mL–1). Variable degrees of enzyme synergism were evident from statistical analysis of the biomass hydrolysis.

Place, publisher, year, edition, pages
John Wiley & Sons, 2021
Keywords
banana peel, biomass, cornmeal, enzymatic hydrolysis, experimental mixture design, sorghum grain bran, Aspergillus, Chemical industry, Enzymes, Saccharification, Sugars, Biological pre-treatment, Biomass hydrolysis, Commercial sources, Environment friendly, Enzymatic conversions, Enzymatic saccharification, Experimental mixture designs, Renewable energies, Mixtures
National Category
Biocatalysis and Enzyme Technology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-25985 (URN)10.1002/bbb.2251 (DOI)000656801500001 ()2-s2.0-85107341277 (Scopus ID)
Available from: 2021-07-09 Created: 2021-07-09 Last updated: 2021-07-13Bibliographically approved
Patel, A., Mahboubi, A., Sárvári Horváth, I., Taherzadeh, M. J., Rova, U., Christakopoulos, P. & Matsakas, L. (2021). Volatile Fatty Acids (VFAs) Generated by Anaerobic Digestion Serve as Feedstock for Freshwater and Marine Oleaginous Microorganisms to Produce Biodiesel and Added-Value Compounds. Frontiers in Microbiology, 12, Article ID 614612.
Open this publication in new window or tab >>Volatile Fatty Acids (VFAs) Generated by Anaerobic Digestion Serve as Feedstock for Freshwater and Marine Oleaginous Microorganisms to Produce Biodiesel and Added-Value Compounds
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2021 (English)In: Frontiers in Microbiology, E-ISSN 1664-302X, Vol. 12, article id 614612Article in journal (Refereed) Published
Abstract [en]

Given an increasing focus on environmental sustainability, microbial oils have been suggested as an alternative to petroleum-based products. However, microbial oil production relies on the use of costly sugar-based feedstocks. Substrate limitation, elevated costs, and risk of contamination have sparked the search for alternatives to sugar-based platforms. Volatile fatty acids are generated during anaerobic digestion of organic waste and are considered a promising substrate for microbial oil production. In the present study, two freshwater and one marine microalga along with two thraustochytrids were evaluated for their potential to produce lipids when cultivated on volatile fatty acids generated from food waste via anaerobic digestion using a membrane bioreactor. Freshwater microalgae Auxenochlorella protothecoides and Chlorella sorokiniana synthesized lipids rich in palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (C18:2). This composition corresponds to that of soybean and jatropha oils, which are used as biodiesel feedstock. Production of added-value polyunsaturated fatty acids (PUFA) mainly omega-3 fatty acids was examined in three different marine strains: Aurantiochytrium sp. T66, Schizochytrium limacinum SR21, and Crypthecodinium cohnii. Only Aurantiochytrium sp. T66 seemed promising, generating 43.19% docosahexaenoic acid (DHA) and 13.56% docosapentaenoic acid (DPA) in total lipids. In summary, we show that A. protothecoides, C. sorokiniana, and Aurantiochytrium sp. T66 can be used for microbial oil production from food waste material.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2021
Keywords
biofuels, microalgae, oleaginous microorganisms, omega-3 fatty acids, volatile fatty acids, acetic acid, biodiesel, butyric acid, docosahexaenoic acid, docosapentaenoic acid, fresh water, hexanoic acid, linoleic acid, oleic acid, palmitic acid, polyunsaturated fatty acid, propionic acid, stearic acid, valeric acid, volatile fatty acid, anaerobic digestion, Article, Aurantiochytrium, Auxenochlorella protothecoides, biomass, cell culture technique, cell growth, Chlorella sorokiniana, controlled study, Crypthecodinium cohnii, dry weight, fermentation, fluorescence microscopy, food waste, high performance liquid chromatography, Jatropha, lipid fingerprinting, lipid storage, marine species, mass fragmentography, microalga, nonhuman, Schizochytrium limacinum
National Category
Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-25819 (URN)10.3389/fmicb.2021.614612 (DOI)000616920300001 ()33584617 (PubMedID)2-s2.0-85100753813 (Scopus ID)
Available from: 2021-07-06 Created: 2021-07-06 Last updated: 2024-01-17
Wainaina, S., Mukesh Kumar, A., Sárvári Horváth, I. & Taherzadeh, M. J. (2020). Anaerobic digestion of food waste to volatile fatty acids and hydrogen at high organic loading rates in immersed membrane bioreactors. Renewable energy
Open this publication in new window or tab >>Anaerobic digestion of food waste to volatile fatty acids and hydrogen at high organic loading rates in immersed membrane bioreactors
2020 (English)In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682Article in journal (Refereed) Published
Abstract [en]

The organic loading rate (OLR) is an essential parameter that controls the anaerobic digestion process. This work investigated the performance of immersed membrane bioreactors operated at high OLRs of 4, 6, 8 and 10 g volatile solids (VS)/L/d regarding the fermentation behavior, product recovery and microbial dynamics during the acidogenic fermentation of food waste to volatile fatty acids (VFAs) and hydrogen. The highest yield of 0.52 g VFA/ gVSadded was attained at 6 g VS/L/d, while an optimal hydrogen yield of 14.7 NmL/ gVSadded was obtained at 8 g VS/L/d. The bacterial populations, analyzed using 16S rRNA gene amplicon sequencing, consisted mainly of Firmicutes and Actinobacteria at OLRs 4 and 8 g VS/L/d while Firmicutes, Actinobacteria and Proteobacteria phyla dominated at 6 and 10 g VS/L/d. Moreover, the presence of Clostridium and Lactobacillus genera correlated with the acetate, butyrate, caproate and lactate production.

Keywords
In-situ product recovery Immersed membrane bioreactor High organic loading rate Volatile fatty acids Microbial dynamics
National Category
Engineering and Technology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-22766 (URN)10.1016/j.renene.2020.01.138 (DOI)000536949600094 ()2-s2.0-85078880176 (Scopus ID)
Funder
Swedish Agency for Economic and Regional GrowthMoRe ResearchSwedish Research Council
Available from: 2020-02-03 Created: 2020-02-03 Last updated: 2024-02-01Bibliographically approved
Habagil, M., Keucken, A. & Sárvári Horváth, I. (2020). Biogas Production from Food Residues-The Role of Trace Metals and Co-Digestion with Primary Sludge. Environments, 7(6)
Open this publication in new window or tab >>Biogas Production from Food Residues-The Role of Trace Metals and Co-Digestion with Primary Sludge
2020 (English)In: Environments, E-ISSN 2076-3298, Vol. 7, no 6Article in journal (Refereed) Published
Abstract [en]

The majority of municipal Wastewater Treatment Plants (WWTPs) in Sweden produce biogas from sewage sludge. In order to increase the methane production, co-digestion of internal sludge with Organic Fraction of Municipal Solid Waste (OFMSW) might be feasible in the future. The objective of this study was therefore to find a beneficial solution for the utilization of OFMSW at the WWTP in Varberg, Sweden. The effects of co-digesting primary sludge (PS) and OFMSW collected in the municipality, in different mixing ratios, were investigated by semi-continuous anaerobic digestion assays. Furthermore, the effects of the addition of a commercial trace elements mixture solution (CTES), available on the market in Sweden, were also examined. Co-digestion of OFMSW and PS resulted in specific methane yields of 404, 392, and 375 NmL CH4/g volatile solids (VS), obtained during semi-continuous operations of 301, 357 and 385 days, for the reactors fed with OMFSW:PS ratio of 4:1, 3:1, and 1:1, and at maximum organic loading rates (OLRs) achieved of 4.0, 4.0 and 5.0 gVS/L/d, respectively. Furthermore, mono-digestion of OFMSW failed already at OLR of 1.0 gVS/L/d, however, an OLR of 4.0 gVS/L/d could be achieved with addition of 14 mu L/g VS Commercial Trace Element Solutions (CTES) leading to 363 mL CH4/g VS methane production. These experiments were running during 411 days. Hence, higher process efficiency was obtained when using co-digestion of OFMSW and PS compared to that of OFMSW in mono-digestion. Co-digestion is a more feasible option where a balanced Carbon/Nitrogen (C/N) ratio and nutrient supply can be maintained.

Place, publisher, year, edition, pages
MDPI, 2020
Keywords
co-digestion, process stability, methane production, primary sludge, OFMSW, trace metals
National Category
Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-24834 (URN)10.3390/environments7060042 (DOI)000559184200003 ()2-s2.0-85085878514 (Scopus ID)
Available from: 2021-01-21 Created: 2021-01-21 Last updated: 2023-02-20Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-1456-1840

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