High-throughput screening of inhibitors tolerance Saccharomyces cerevisiae from lignocellulosic pretreatment by ARTP-MMC

In order to enhance the tolerance of Saccharomyces cerevisiae to inhibitors such as formic acid, furfural, 5-hydroxymethyl-furfural produced by lignocellulosic pretreatment, and to ensure that the ethanol production capacity of S. cerevisiae was not affected, using Angel's super yeast as the starting strain, an adaptive evolution method combining atmospheric room temperature plasma (ARTP) mutagenesis and microbial microdroplets culture (MMC) with high throughput screening of lignocellulose-resistant preconditioning inhibitors for S. cerevisiae was studied. a dominate mutant strain with strong resistance was obtained and its inhibition resistance and ethanol production capacity were evaluated. The research showed that the optimal mutation conditions for the strain were as follows: mutation power 110 W, mutation time 140 s, cultivation time 12 h, and the compound inhibitors gradient combination of CI4-CI6 for adaptive evolution in the micro-droplet microbial culture system. So the optimal mutant strain M8 was obtained through high-throughput screening. The strain could tolerate 16% ethanol, had good high temperature resistance, and could grow normally at 55 ℃ heat shock for 5 min. After 10 L fermenter culture, the maximum ethanol yield was 56.29 g/L, and the sugar-alcohol conversion rate was 0.49 g/g, reaching 96.67% of the theoretical value. The study provided excellent S. cerevisiae for the high-quality utilization of lignocellulosic biomass and was of great significance for promoting cellulose ethanol production.