Small scale screening of yeast strains enables high-throughput evaluation of performance in lignocellulose hydrolysates.

Abstract

Second generation biorefineries demand efficient lignocellulosic hydrolysate fermenting strains and recent advances in strain isolation and engineering have progressed the bottleneck in developing production hosts from generation of strains into testing these under relevant conditions. In this paper, we introduce a methodology for high-throughput analysis of yeast strains directly in lignocellulosic hydrolysates. The Biolector platform was used to assess aerobic and anaerobic growth of 12 Saccharomyces cerevisiae strains and their ΔPdr12 mutants in wheat straw hydrolysate. The strains evaluated included lab, industrial and wild type strains and the screening could capture significant differences in growth and ethanol production among the strains. The methodology was also demonstrated with corn stover hydrolysate and the results were in line with shake flask cultures. Our study demonstrates that growth in lignocellulosic hydrolysates could be rapidly monitored using 1 ml cultures and that measuring growth and product formation under relevant conditions are crucial for evaluating strain performance.