Advances in mechanisms and modifications for rendering yeast thermotolerance

Abstract

Thermotolerant Saccharomyces cerevisiae is widely regarded as an attractive strain with which to accomplish the coupling of enzyme saccharification, ethanol fermentation and ethanol distillation in non-grain fuel bioethanol fermentation systems, and it has many advantages for increasing the ethanol yield and reducing production costs. This review provided an overview of the yeast heat-resistant mechanisms from six aspects, including gene expression responses, heat shock proteins, trehalose, ATPase, the ubiquitin-proteasome pathway and heat-induced antioxidant defenses. Innovative methods, such as random and rational strategies for improving yeast thermotolerance, were further discussed, and several special cases were provided. To rationally engineer thermotolerance in yeast, the advances in employing heat-resistant mechanisms of thermophiles were particularly discussed. By designing and constructing heat-resistant devices consists of heat-resistant parts from thermophiles to yeast, a superior thermotolerance of S. cerevisiae has been achieved, providing a new system with important applications for research regarding the improvement of the robustness of microbes.

Keywords: Heat-resistant devices; Heat-resistant modification; Non-gain fuel bioethanol; Saccharomyces cerevisiae; Thermophiles; Thermotolerant mechanism.