Fermentation of glucose-xylose-arabinose mixtures by a synthetic consortium of single-sugar-fermenting Saccharomyces cerevisiae strains

Fermentation of glucose-xylose-arabinose mixtures by a synthetic consortium of single-sugar-fermenting Saccharomyces cerevisiae strains

Verhoeven, M.D. (TU Delft BT/Industriele Microbiologie)
de Valk, S.C. (TU Delft BT/Industriele Microbiologie)
Daran, J.G. (TU Delft BT/Industriele Microbiologie)
van Maris, A.J.A. (TU Delft BT/Industriele Microbiologie)
Pronk, J.T. (TU Delft BT/Biotechnologie)

BT/Biotechnologie

2018

D-Glucose, D-xylose and L-arabinose are major sugars in lignocellulosic hydrolysates. This study explores fermentation of glucose-xylose-arabinose mixtures by a consortium of three ‘specialist’ Saccharomyces cerevisiae strains. A D-glucose- and L-arabinose-tolerant xylose specialist was constructed by eliminating hexose phosphorylation in an engineered xylose-fermenting strain and subsequent laboratory evolution. A resulting strain anaerobically grew and fermented D-xylose in the presence of 20 g L-1 of D-glucose and L-arabinose. A synthetic consortium that additionally comprised a similarly obtained arabinose specialist and a pentose-non-fermenting laboratory strain, rapidly and simultaneously converted D-glucose and L-arabinose in anaerobic batch cultures on three-sugar mixtures. However, performance of the xylose specialist was strongly impaired in these mixed cultures. After prolonged cultivation of the consortium on three-sugar mixtures, the time required for complete sugar conversion approached that of a previously constructed and evolved ‘generalist’ strain. In contrast to the generalist strain, whose fermentation kinetics deteriorated during prolonged repeated-batch cultivation on a mixture of 20 g L-1 D-glucose, 10 g L-1 D-xylose and 5 g L-1 L-arabinose, the evolved consortium showed stable fermentation kinetics. Understanding the interactions between specialist strains is a key challenge in further exploring the applicability of this synthetic consortium approach for industrial fermentation of lignocellulosic hydrolysates.

bioethanol
mixed-culture fermentationt
evolutionary engineering
pentose fermentation
Yeast

http://resolver.tudelft.nl/uuid:4d6512c4-3a2c-4095-b941-913e73df2497

https://doi.org/10.1093/femsyr/foy075

1567-1356

FEMS Yeast Research, 18 (8)

Accepted Author Manuscript

Institutional Repository

journal article

© 2018 M.D. Verhoeven, S.C. de Valk, J.G. Daran, A.J.A. van Maris, J.T. Pronk