Prado Cleiton D, Mandrujano Gustavo P L, Souza Jonas P, Sgobbi Flávia B, Novaes Hosana R, da Silva João P M O, Alves Mateus H R, Eliodório Kevy P, Cunha Gabriel C G, Giudici Reinaldo, Procópio Diele P, Basso Thiago O, Malavazi Iran, Cunha Anderson F
Genetic and Evolution Department, Universidade Federal de São Carlos (UFSCar), São Carlos, SP 13565-905 Brazil.
Chemical Engineering Department, Escola Politécnica, Universidade de São Paulo (USP), São Paulo, SP 05508-010 Brazil.
Biotechnol Biofuels. 2020 Oct 27;13:178. doi: 10.1186/s13068-020-01817-6. eCollection 2020.
The use of thermotolerant yeast strains can improve the efficiency of ethanol fermentation, allowing fermentation to occur at temperatures higher than 40 °C. This characteristic could benefit traditional bio-ethanol production and allow simultaneous saccharification and fermentation (SSF) of starch or lignocellulosic biomass.
We identified and characterized the physiology of a new thermotolerant strain (LBGA-01) able to ferment at 40 °C, which is more resistant to stressors as sucrose, furfural and ethanol than CAT-1 industrial strain. Furthermore, this strain showed similar CAT-1 resistance to acetic acid and lactic acid, and it was also able to change the pattern of genes involved in sucrose assimilation ( and ). Genes related to the production of proteins involved in secondary products of fermentation were also differentially regulated at 40 °C, with reduced expression of genes involved in the formation of glycerol (), acetate ( and ), and acetyl-coenzyme A synthetase 2 (). Fermentation tests using chemostats showed that LBGA-01 had an excellent performance in ethanol production in high temperature.
The thermotolerant LBGA-01 strain modulates the production of key genes, changing metabolic pathways during high-temperature fermentation, and increasing its resistance to high concentration of ethanol, sugar, lactic acid, acetic acid, and furfural. Results indicate that this strain can be used to improve first- and second-generation ethanol production in Brazil.
使用耐热酵母菌株可以提高乙醇发酵效率，使发酵能够在高于40°C的温度下进行。这一特性可能有益于传统生物乙醇生产，并允许淀粉或木质纤维素生物质的同步糖化和发酵（SSF）。
我们鉴定并表征了一种能够在40°C发酵的新型耐热菌株（LBGA-01）的生理学特性，该菌株比CAT-1工业菌株对蔗糖、糠醛和乙醇等应激源具有更强的抗性。此外，该菌株对乙酸和乳酸的抗性与CAT-1相似，并且它还能够改变参与蔗糖同化（和）的基因模式。与发酵次级产物相关的蛋白质生产相关基因在40°C时也受到差异调节，参与甘油（）、乙酸盐（和）以及乙酰辅酶A合成酶2（）形成的基因表达降低。使用恒化器进行的发酵试验表明，LBGA-01在高温乙醇生产中具有优异的性能。
耐热LBGA-01菌株调节关键基因的产生，在高温发酵过程中改变代谢途径，并增加其对高浓度乙醇、糖、乳酸、乙酸和糠醛的抗性。结果表明，该菌株可用于提高巴西第一代和第二代乙醇的产量。
