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Performance of xylose-fermenting yeasts in oat and soybean hulls hydrolysate and improvement of ethanol production using immobilized cell systems

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Abstract

We investigated the fermentation of a mixture of oat and soybean hulls (1:1) subjected to acid (AH) or enzymatic (EH) hydrolyses, with both showing high osmotic pressures (> 1200 Osm kg−1) for the production of ethanol. Yeasts of genera Spathaspora, Scheffersomyces, Sugiymaella, and Candida, most of them biodiverse Brazilian isolates and previously untested in bioprocesses, were cultivated in these hydrolysates. Spathaspora passalidarum UFMG-CM-469 showed the best ethanol production kinetics in suspended cells cultures in acid hydrolysate, under microaerobic and anaerobic conditions. This strain was immobilized in LentiKats® (polyvinyl alcohol) and cultured in AH and EH. Supplementation of hydrolysates with crude yeast extract and peptone was also performed. The highest ethanol production was obtained using hydrolysates supplemented with crude yeast extract (AH-CYE and EH-CYE) showing yields of 0.40 and 0.44 g g−1, and productivities of 0.39 and 0.29 g (L h)−1, respectively. The reuse of the immobilized cells was tested in sequential fermentations of AH-CYE, EH-CYE, and a mixture of acid and enzymatic hydrolysates (AEH-CYE) operated under batch fluidized bed, with ethanol yields ranging from 0.31 to 0.40 g g−1 and productivities from 0.14 to 0.23 g (L h)−1. These results warrant further research using Spathaspora yeasts for second-generation ethanol production.

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References

  • Antunes FAF, Santos JC, Chandel AK, Milessi TSS, Peres GFD, Da Silva SS (2016) Hemicellulosic ethanol production by immobilized Wild Brazilian Yeast Scheffersomyces shehatae UFMG-HM 52.2: effects of cell concentration and stirring rate. Curr Microbiol 72:133–138

    Article  PubMed  CAS  Google Scholar 

  • Antunes FAF, Santos JC, Chandel AK, Carrier DJ, Peres GFD, Milessi TSS, Da Silva SS (2019) Repeated batches as a feasible industrial process for hemicellulosic ethanol production from sugarcane bagasse by using immobilized yeast cells. Cellulose 26:3787–3800

    Article  CAS  Google Scholar 

  • Attfield PV, Bell PJ (2006) Use of population genetics to derive nonrecombinant Saccharomyces cerevisiae strains that grow using xylose as a sole carbon source. FEMS Yeast Res 6:862–868

    Article  PubMed  CAS  Google Scholar 

  • Bezbradica D, Obradovic B, Leskosek-Cukalovic I, Bugarski B, Nedovic V (2007) Immobilization of yeast cells in PVA particles for beer fermentation. Process Biochem 42:1348–1351

    Article  CAS  Google Scholar 

  • Bonn G, Bobleter O (1984) HPLC-analyses of plant biomass hydrolysis and fermentation solutions. Chromatographia 18:445–448

    Article  CAS  Google Scholar 

  • Cadete RM, Rosa CA (2018) The yeasts of the genus Spathaspora: potential candidates for second-generation biofuel production. Yeast 35:191–199

    Article  PubMed  CAS  Google Scholar 

  • Cadete RM, Melo MA, Dussán KJ, Rodrigues RCLB, Silva SS, Zilli JE, Vital MJS, Gomes FCO, Lachance M-A, Rosa CA (2012) Diversity and physiological characterization of D-xylose-fermenting yeasts isolated from the Brazilian Amazonian Forest. PloS One 7:e43135

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  • Cadete RM, Melo MA, Zilli JE, Vital MJS, Mouro A, Prompt AH, Gomes FCO, Stambuk BU, Lachance M-A, Rosa CA (2013) Spathaspora brasiliensis sp. nov., Spathaspora suhii sp. nov., Spathaspora roraimanensis sp. nov. and Spathaspora xylofermentans sp. nov., four novel d-xylose-fermenting yeast species from Brazilian Amazonian forest. Antonie Leeuwenhoek 103:421–431

    Article  PubMed  CAS  Google Scholar 

  • Cadete RM, De Las Heras AM, Sandström AG, Ferreira C, Gírio F, Gorwa-Grauslund M-F, Rosa CA, Fonseca C (2016) Exploring xylose metabolism in Spathaspora species: XYL1.2 from Spathaspora passalidarum as the key for efficient anaerobic xylose fermentation in metabolic engineered Saccharomyces cerevisiae. Biotechnol Biofuels 9:167

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  • Cortivo PRD, Hickert LR, Hector R, Ayub MAZ (2018) Fermentation of oat and soybean hull hydrolysates into ethanol and xylitol by recombinant industrial strains of Saccharomyces cerevisiae under diverse oxygen environments. Ind Crops Prod 113:10–18

    Article  CAS  Google Scholar 

  • Cunha JT, Soares PO, Romaní A, Thevelein JM, Domingues L (2019) Xylose fermentation efficiency of industrial Saccharomyces cerevisiae yeast with separate or combined xylose reductase/xylitol dehydrogenase and xylose isomerase pathways. Biotechnol Biofuels 12:20

    Article  PubMed  PubMed Central  Google Scholar 

  • Fan C, Qi K, Xia X-X, Zhong J-J (2013) Efficient ethanol production from corncob residues by repeated fermentation of an adapted yeast. Bioresour Technol 136C:309–315

    Article  CAS  Google Scholar 

  • Ferreira AD, Mussatto SI, Cadete RM, Rosa CA, Silva SS (2011) Ethanol production by a new pentose-fermenting yeast strain, Scheffersomyces stipitis UFMG-IMH 43.2, isolated from the Brazilian forest. Yeast 28:547–554

    Article  PubMed  CAS  Google Scholar 

  • Gabardo S, Pereira GF, Klein MP, Rech R, Hertz PF, Ayub MAZ (2016) Dynamics of yeast immobilized-cell fluidized-bed bioreactors systems in ethanol fermentation from lactose-hydrolyzed whey and whey permeate. Bioprocess Biosyst Eng 39:141–150

    Article  PubMed  CAS  Google Scholar 

  • Gisele D, Luana T, Samila R, Maxwel A (2017) Efficient production of second generation ethanol and xylitol by yeasts from Amazonian beetles (Coleoptera) and their galleries. Afr J Microbiol Res 11:814–824

    Article  Google Scholar 

  • Hahn-Hägerdal B, Karhumaa K, Fonseca C, Spencer-Martins I, Gorwa-Grauslund M (2007) Towards industrial pentose-fermenting yeast strains. Appl Microbiol Biotechnol 74:937–953

    Article  PubMed  CAS  Google Scholar 

  • Hector RE, Dien BS, Cotta MA, Qureshi N (2011) Engineering industrial Saccharomyces cerevisiae strains for xylose fermentation and comparison for switchgrass conversion. J Ind Microbiol Biotechnol 38:1193–1202

    Article  PubMed  CAS  Google Scholar 

  • Hickert LR, Cruz MM, Dillon AJP, Fontana RC, Rosa CA, Ayub MAZ (2014) Fermentation kinetics of acid–enzymatic soybean hull hydrolysate in immobilized-cell bioreactors of Saccharomyces cerevisiae, Candida shehatae, Spathaspora arborariae, and their co-cultivations. Biochem Eng J 88:61–67

    Article  CAS  Google Scholar 

  • Hittinger C, Rokas A, Bai F-Y, Boekhout T, Gonçalves P, Jeffries T, Kominek J, Lachance M-A, Libkind D, Rosa C, Sampaio J, Kurtzman C (2015) Genomics and the making of yeast biodiversity. Curr Opin Genet Dev 35:100–109

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  • Hohmann S (2002) Osmotic stress signaling and osmoadaptation in yeasts. Microbiol Mol Biol Rev 66:300–372

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  • Hou X (2011) Anaerobic xylose fermentation by Spathaspora passalidarum. Appl Microbiol Biotechnol 94:205–214

    Article  PubMed  CAS  Google Scholar 

  • Isikgor F, Becer R (2015) Lignocellulosic biomass: a sustainable platform for production of bio-based chemicals and polymers. Polym Chem 6:4497–4559

    Article  CAS  Google Scholar 

  • Jansen MLA, Bracher JM, Papapetridis I, Verhoeven MD, De Bruijn H, De Waal PP, Van Maris AJA, Klaassen P, Pronk JT (2017) Saccharomyces cerevisiae strains for second-generation ethanol production: from academic exploration to industrial implementation. FEMS Yeast 17:1–20

    Google Scholar 

  • Kachrimanidou V, Vlysidis A, Kopsahelis N, Kookos I (2021) Increasing the volumetric productivity of fermentative ethanol production using a fed-batch vacuferm process. Biomass Convers Biorefin 11:673–680

    Article  CAS  Google Scholar 

  • Kourkoutas Y, Bekatorou A, Banat IM, Marchant R, Koutinas AA (2004) Immobilization technologies and support materials suitable in alcohol beverages production: a review. Food Microbiol 21:377–397

    Article  CAS  Google Scholar 

  • Krasňan V, Stloukal R, Rosenberg M, Rebroš M (2016) Immobilization of cells and enzymes to LentiKats®. Appl Microbiol Biotechnol 100:2535–2553

    Article  PubMed  CAS  Google Scholar 

  • Kuhad RC, Gupta R, Khasa YP (2010) Bioethanol production from lignocellulosic biomass: an overview. In: Sharma PM, Lal B (eds) Wealth from waste, 3rd edn. Teri Press, New Delhi, pp 53–106

    Google Scholar 

  • Kurtzman CP (2011) Millerozyma Kurtzman & M. Suzuki (2010). In: Kurtzman CP, Fell JW, Boekhout T (eds) The yeasts, 5th edn. Elsevier, London, pp 625–628

    Chapter  Google Scholar 

  • Lee HS, Rouseff RL, Nagy S (1986) HPLC determination of furfural and 5-hydroxymethylfurfural in citrus juices. J Food Sci 51:1075–1076

    Article  CAS  Google Scholar 

  • Lopes MR, Morais CG, Kominek J, Cadete RM, Soares MA, Uetanabaro APT, Fonseca C, Lachance M-A, Hittinger CT, Rosa CA (2016) Genomic analysis and D-xylose fermentation of three novel Spathaspora species: Spathaspora girioi sp. nov., Spathaspora hagerdaliae f. a., sp. nov. and Spathaspora gorwiae f. a., sp. nov. FEMS Yeast Res 16:1–12

    Article  CAS  Google Scholar 

  • Lopes D, Rosa C, Hector R, Dien B, Mertens J, Ayub MAZ (2017) Influence of genetic background of engineered xylose-fermenting industrial Saccharomyces cerevisiae strains for ethanol production from lignocellulosic hydrolysates. J Ind Microbiol Biotechnol 44:1–14

    Article  CAS  Google Scholar 

  • Lopes MR, Lara CA, Moura MEF, Uetanabaro APT, Morais PB, Vital MJS, Rosa CA (2018) Characterisation of the diversity and physiology of cellobiose-fermenting yeasts isolated from rotting wood in Brazilian ecosystems. Fungal Biol 122:668–676

    Article  PubMed  CAS  Google Scholar 

  • Martiniano S, Chandel A, Soares L, Pagnocca F, Silva SS (2013) Evaluation of novel xylose-fermenting yeast strains from Brazilian forests for hemicellulosic ethanol production from sugarcane bagasse. 3 Biotech 3:345–352

    Article  PubMed  PubMed Central  Google Scholar 

  • Morais CG, Lara CA, Marques S, Fonseca C, Lachance MA, Rosa CA (2013) Sugiyamaella xylanicola sp. nov., a xylan-degrading yeast species isolated from rotting wood. Int J Syst Evol Microbiol 63:2356–2360

    Article  PubMed  CAS  Google Scholar 

  • Moya A, Bravo V, Mateo S, Sánchez S (2008) Fermentation of acid hydrolysates from olive-tree pruning debris by Pachysolen tannophilus. Bioprocess Biosyst Eng 31:611–617

    Article  PubMed  CAS  Google Scholar 

  • Nguyen NH, Suh SO, Marshall CJ, Blackwell M (2006) Morphological and ecological similarities: wood-boring beetles associated with novel xylose-fermenting yeasts, Spathaspora passalidarum gen. sp. nov. and Candida jeffriesii sp. nov. Mycol Res 110:1232–1241

    Article  PubMed  Google Scholar 

  • Ping Y, Ling HZ, Song G, Ge JP (2013) Xylitol production from non-detoxified corncob hemicellulose acid hydrolysate by Candida tropicalis. Biochem Eng J 75:86–91

    Article  CAS  Google Scholar 

  • Pitarelo AP, Fonseca CSD, Chiarello LM, Gírio FM, Ramos LP (2016) Ethanol production from sugarcane bagasse using phosphoric acid-catalyzed steam explosion. J Braz Chem Soc 27:1889–1898

    CAS  Google Scholar 

  • Prado E, Rivas EM, Silóniz MI, Diezma B, Barreiro P, Peinado J (2014) Quantitative analysis of morphological changes in yeast colonies growing on solid medium: the eccentricity and Fourier indexes. Yeast 31:431–440

    Article  CAS  Google Scholar 

  • Rakin M, Mojovic L, Nikolić S, Vukasinovic M, Nedovic V (2009) Bioethanol production by immobilized Sacharomyces cerevisiae var. ellipsoideus cells. Afr J Biotechnol 8:464–471

    CAS  Google Scholar 

  • Robak K, Balcerek M (2018) Review of second generation bioethanol production from residual biomass. Food Technol Biotechnol 56:174–187

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  • Schirmer-Michel AC, Flôres SH, Hertz PF, Ayub MAZ (2009) Effect of oxygen transfer rates on alcohols production by Candida guilliermondii cultivated on soybean hull hydrolysate. J Chem Technol Biotechnol 84:223–228

    Article  CAS  Google Scholar 

  • Sehnem NT, Silva AM, Leite FCB, Barros PW, Morais MA, Ayub MAZ (2013) 5-Hydroxymethylfurfural induces ADH7 and ARI1 expression in tolerant industrial Saccharomyces cerevisiae strain P6H9 during bioethanol production. Bioresour Technol 133:190–196

    Article  PubMed  CAS  Google Scholar 

  • Soares J, Demeke MM, Van de Velde M, Foulquié-Moreno MR, Kerstens D, Sels BF, Verplaetse A, Fernandes AAR, Thevelein JM, Fernandes PMB (2017) Fed-batch production of green coconut hydrolysates for high-gravity second-generation bioethanol fermentation with cellulosic yeast. Bioresour Technol 244:234–242

    Article  PubMed  CAS  Google Scholar 

  • Torres-Mayanga PC, Lachos-Perez D, Mudhoo A, Kumar S, Brown AB, Tyufekchiev M, Dragone G, Mussatto SI, Rostagno MA, Timko M, Forster-Carneiro T (2019) Production of biofuel precursors and value-added chemicals from hydrolysates resulting from hydrothermal processing of biomass: a review. Biomass Bioenergy 130:105397

    Article  CAS  Google Scholar 

  • Verbelen PJ, De Schutter DP, Delvaux F, Verstrepen KJ, Delvaux FR (2006) Immobilized yeast cell systems for continuous fermentation applications. Biotechnol Lett 28:1515–1525

    Article  PubMed  CAS  Google Scholar 

  • Vleet J, Jeffries T (2009) Yeast metabolic engineering for hemicellulosic ethanol production. Curr Opin Biotechnol 20:300–306

    Article  PubMed  CAS  Google Scholar 

  • Zahed O, Jouzani GS, Abbasalizadeh S, Khodaiyan F, Tabatabaei M (2016) Continuous co-production of ethanol and xylitol from rice straw hydrolysate in a membrane bioreactor. Folia Microbiol 61:179–189

    Article  CAS  Google Scholar 

Download references

Acknowledgements

The authors wish to thank Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Coordenação do Aperfeiçoamento de Pessoal do Ensino Superior (CAPES), Finance Code 001, and FAPERGS for their financial support and scholarships for this project. The authors thank Cereais Naturale (Lagoa Vermelha, RS, Brazil) for supplying the oat hulls.

Supplementary Information

Supplementary Material 2. Performance of yeasts fermenting concentrated hydrolysate resulting from acid treatment (AH) in an orbital shaker at 28 oC and 180 rpm under microaerophilic conditions.

Figure S2.1. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Spathaspora brasiliensis UFMG-HMD-19.3. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S2.2. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Spathaspora girioi UFMG-CM-Y302. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure 2.3. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Spathaspora roraimanensis UFMG-XMD-23.2. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S2.4. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Spathaspora xylofermentans UFMG-HMD-23.3. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S2.5. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Spathaspora passalidarum CBS-10501. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S2.6. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Spathaspora passalidarum UFMG-CM-469. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S2.7. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Candida guilliermondii NRRL Y-2075. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S2.8. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Scheffersomyces queiroziae UFMG-CM-416. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S2.9. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Scheffersomyces amazonensis UFMG-CM-418. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S2.10. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Sugiymaella xylanicola UFMG-CM-Y1884. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S2.11. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Scheffersomyces stipitis UFMG-IMH- 43.2. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S2.12. Fermentation of concentrated hydrolysate resulting from acid treatment (AH) in orbital shaker at 28 °C and 180 rpm by Saccharomyces cerevisiae YRH1415. (A) Biomass formation (CFU mL−1). (B) Kinetics of substrates consumption and products formation; (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Supplementary Material 3. Fermentation of AH and EH by Sp. passalidarum UFMG-CM-469 with immobilized cells in LentiKats® and the effect of supplementation.

Figure S3.1. Kinetics of substrate consumption and products formation in fermentation of AH (A), AH-CYE (B), and AH-CYEP (C) by Sp. passalidarum UFMG-CM-469 immobilized in LentiKats® in orbital shaker at 28 °C and 180 rpm. (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

Figure S3.2. Kinetics of substrate consumption and products formation in fermentation of EH (A), EH-CYE (B), and EH-CYEP (C) by Sp. passalidarum UFMG-CM-469 immobilized in LentiKats® in orbital shaker at 28 °C and 180 rpm. (open circle) Glucose, (open square) Xylose, (filled circle) Ethanol, (filled square) Xylitol, and (filled triangle) glycerol. Results are the mean of duplicates.

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Authors and Affiliations

  1. Biotechnology & Biochemical Engineering Laboratory (BiotecLab), Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, PO Box 15090, Porto Alegre, RS, 91501-970, Brazil

    Paulo Roberto Dall Cortivo, Luiza Fichtner Aydos & Marco Antônio Záchia Ayub

  2. State University of Rio Grande do Sul, Av. Bento Gonçalves, 8855, Porto Alegre, RS, 91540-000, Brazil

    Lilian Raquel Hickert

  3. Department of Microbiology, ICB, C.P. 486, State University of Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil

    Carlos Augusto Rosa

  4. Bioenergy Research Unit, USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 North University Street, Peoria, IL, 61604, USA

    Ronald E. Hector & Jeffrey A. Mertens

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  1. Paulo Roberto Dall Cortivo
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  2. Luiza Fichtner Aydos
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Cortivo, P.R.D., Aydos, L.F., Hickert, L.R. et al. Performance of xylose-fermenting yeasts in oat and soybean hulls hydrolysate and improvement of ethanol production using immobilized cell systems. Biotechnol Lett 43, 2011–2026 (2021). https://doi.org/10.1007/s10529-021-03182-2

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