Improvement of inhibitors tolerance of Saccharomyces cerevisiae by overexpressing of long chain sphingoid kinases encoding gene LCB4.
- Author:
Yanyan HE
1
;
Lihan ZI
1
;
Baohui ZHANG
1
;
Jianren XU
1
;
Dandan WANG
1
;
Fengwu BAI
2
Author Information
- Publication Type:Journal Article
- Keywords: LCB4; acetic acid stress; ethanol fermentation; furfural stress; vanillin stress
- From: Chinese Journal of Biotechnology 2018;34(6):906-915
- CountryChina
- Language:Chinese
- Abstract: By-products released from pretreatment process of lignocellulose seriously hinder the development of cellulosic fuel ethanol. Therefore, the great way to increase the efficiency of cellulosic ethanol production is improvement of Saccharomyces cerevisiae tolerance to these inhibitors. In this work, the effects of LCB4 gene overexpression on cell growth and ethanol fermentation in S. cerevisiae S288C under acetic acid, furfural and vanillin stresses were studied. Compared to the control strain S288C-HO, the recombinant strain S288C-LCB4 grew better on YPD solid medium containing 10 g/L acetic acid, 1.5 g/L furfural and 1 g/L vanillin. Ethanol yields of recombinant strain S288C-LCB4 were 0.85 g/(L·h), 0.76 g/(L·h) and 1.12 g/(L·h) when 10 g/L acetic acid, 3 g/L furfural and 2 g/L vanillin were supplemented into the fermentation medium respectively, which increased by 34.9%, 85.4% and 330.8% than the control strain S288C-HO. Meanwhile, ethanol fermentation time was reduced by 30 h and 44 h under furfural and vanillin stresses respectively. Further metabolites analysis in fermentation broth showed that the recombinant strain produced more protective compounds, such as glycerol, trehalose and succinic acid, than the control strain, which could be the reason for enhancing strain tolerance to these inhibitors from pretreatment process of lignocellulose. The results indicated that overexpression of LCB4 gene could significantly improve ethanol fermentation in S. cerevisiae S288C under acetic acid, furfural and vanillin stresses.
