Alahuhta Markus, Xu Qi, Knoshaug Eric P, Wang Wei, Wei Hui, Amore Antonella, Baker John O, Vander Wall Todd, Himmel Michael E, Zhang Min
Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
Biotechnol Biofuels. 2021 Jan 6;14(1):6. doi: 10.1186/s13068-020-01856-z.
Consolidated bioprocessing using oleaginous yeast is a promising modality for the economic conversion of plant biomass to fuels and chemicals. However, yeast are not known to produce effective biomass degrading enzymes naturally and this trait is essential for efficient consolidated bioprocessing. We expressed a chimeric cellobiohydrolase I gene in three different oleaginous, industrially relevant yeast: Yarrowia lipolytica, Lipomyces starkeyi, and Saccharomyces cerevisiae to study the biochemical and catalytic properties and biomass deconstruction potential of these recombinant enzymes. Our results showed differences in glycosylation, surface charge, thermal and proteolytic stability, and efficacy of biomass digestion. L. starkeyi was shown to be an inferior active cellulase producer compared to both the Y. lipolytica and S. cerevisiae enzymes, whereas the cellulase expressed in S. cerevisiae displayed the lowest activity against dilute-acid-pretreated corn stover. Comparatively, the chimeric cellobiohydrolase I enzyme expressed in Y. lipolytica was found to have a lower extent of glycosylation, better protease stability, and higher activity against dilute-acid-pretreated corn stover.
利用产油酵母进行联合生物加工是将植物生物质经济转化为燃料和化学品的一种有前景的方式。然而，已知酵母天然不会产生有效的生物质降解酶，而这一特性对于高效联合生物加工至关重要。我们在三种不同的产油且与工业相关的酵母中表达了嵌合纤维二糖水解酶I基因，这三种酵母分别是解脂耶氏酵母、斯达氏油脂酵母和酿酒酵母，以研究这些重组酶的生化和催化特性以及生物质解构潜力。我们的结果显示了糖基化、表面电荷、热稳定性和蛋白酶稳定性以及生物质消化效率方面的差异。与解脂耶氏酵母和酿酒酵母的酶相比，斯达氏油脂酵母被证明是较差的活性纤维素酶生产者，而酿酒酵母中表达的纤维素酶对稀酸预处理玉米秸秆的活性最低。相比之下，在解脂耶氏酵母中表达的嵌合纤维二糖水解酶I酶被发现糖基化程度较低、蛋白酶稳定性较好，并且对稀酸预处理玉米秸秆具有更高的活性。
