Physiological comparisons among Spathaspora passalidarum, Spathaspora arborariae, and Scheffersomyces stipitis reveal the bottlenecks for their use in the production of second-generation ethanol.

Autor: Campos VJ; Departamento de Bioquímica E Biologia Molecular, Universidade Federal de Viçosa, Av. PH Rolfs s/n, Campus Universitário, Viçosa, MG, 36570-900, Brazil., Ribeiro LE; Departamento de Microbiologia, Universidade Federal de Viçosa, Av. PH Rolfs s/n, Campus Universitário, Viçosa, MG, 36570-900, Brazil., Albuini FM; Departamento de Bioquímica E Biologia Molecular, Universidade Federal de Viçosa, Av. PH Rolfs s/n, Campus Universitário, Viçosa, MG, 36570-900, Brazil., de Castro AG; Departamento de Bioquímica E Biologia Molecular, Universidade Federal de Viçosa, Av. PH Rolfs s/n, Campus Universitário, Viçosa, MG, 36570-900, Brazil., Fontes PP; Departamento de Bioquímica E Biologia Molecular, Universidade Federal de Viçosa, Av. PH Rolfs s/n, Campus Universitário, Viçosa, MG, 36570-900, Brazil., da Silveira WB; Departamento de Microbiologia, Universidade Federal de Viçosa, Av. PH Rolfs s/n, Campus Universitário, Viçosa, MG, 36570-900, Brazil., Rosa CA; Departamento de Microbiologia, Universidade Federal de Minas Gerais, ICB, C.P. 486, Belo Horizonte, MG, 31270-901, Brazil., Fietto LG; Departamento de Bioquímica E Biologia Molecular, Universidade Federal de Viçosa, Av. PH Rolfs s/n, Campus Universitário, Viçosa, MG, 36570-900, Brazil. lgfietto@ufv.br.
Jazyk: angličtina
Zdroj: Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology] [Braz J Microbiol] 2022 Jun; Vol. 53 (2), pp. 977-990. Date of Electronic Publication: 2022 Feb 16.
DOI: 10.1007/s42770-022-00693-6
Abstrakt: The microbial conversion of pentoses to ethanol is one of the major drawbacks that limits the complete use of lignocellulosic sugars. In this study, we compared the yeast species Spathaspora arborariae, Spathaspora passalidarum, and Sheffersomyces stipitis regarding their potential use for xylose fermentation. Herein, we evaluated the effects of xylose concentration, presence of glucose, and temperature on ethanol production. The inhibitory effects of furfural, hydroxymethylfurfural (HMF), acetic acid, and ethanol were also determined. The highest ethanol yield (0.44 g/g) and productivity (1.02 g/L.h) were obtained using Sp. passalidarum grown in 100 g/L xylose at 32 °C. The rate of xylose consumption was reduced in the presence of glucose for the species tested. Hydroxymethylfurfural did not inhibit the growth of yeasts, whereas furfural extended their lag phase. Acetic acid inhibited the growth and fermentation of all yeasts. Furthermore, we showed that these xylose-fermenting yeasts do not produce ethanol concentrations greater than 4% (v/v), probably due to the inhibitory effects of ethanol on yeast physiology. Our data confirm that among the studied yeasts, Sp. passalidarum is the most promising for xylose fermentation, and the low tolerance to ethanol is an important aspect to be improved to increase its performance for second-generation (2G) ethanol production. Our molecular data showed that this yeast failed to induce the expression of some classical genes involved in ethanol tolerance. These findings suggest that Sp. passalidarum may have not activated a proper response to the stress, impacting its ability to overcome the negative effects of ethanol on the cells.
(© 2022. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)
Databáze: MEDLINE
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