(191p) The Global Regulator Irre from Deinococcus Radiodurans Enhanced Saccharomyces Cerevisiae Tolerances Toward Furfural

High tolerance to inhibitors is crucial for microorganisms producing ethanol from lignocellulosic hydrolysates. However, strain tolerance involves multiple genes and several complicated regulation mechanisms, so is difficult to achieve by manipulating single genes. It has been reported that the general regulator IrrE from the radioresistant bacterium Deinococcus radiodurans R1 plays an important role in radiation, oxidation, and desiccation resistance. In this study, several irrE gene libraries were constructed by three rounds of error-prone polymerase chain reaction (PCR) and transformed into Saccharomyces cerevisiae. The libraries were then screened for strains exhibiting higher furfural tolerance. The so-called FR mutant grew more effectively than the control group in furfural and glucose/furfural resistance tests, and it showed better ROS eliminating ability than the control strains. According to the furfural stress-related gene expression, the increased furfural tolerance in the FR mutant was associated with NADPH-related pathways. Moreover, the FR mutant was more tolerant to other main inhibitors, such as 5-HMF, formic and acetic acid, than the wild-type. The result demonstrates that the insertion of IrrE from D. radiodurans R1 promises to improve the resistance of Saccharomyces cerevisiae to multiple stresses.