Selection and application of novel high temperature inducible promoters in the tolerant yeast Candida glycerinogenes

Abstract

High temperature fermentation can substantially reduce the contaminations and condensation costs. Candida glycerinogenes was more resistant to high temperature than Saccharomyces cerevisiae. Quantitative real-time PCR results showed that 7 of 33 candidates served as potential high temperature inducible promoters in C.glycerinogenes. Fluorescence analysis indicated that PCgcwp1 showed the highest activity at 42°C. PCgaac and PCgpot1 showed medium-high expression, while PCghsp12, PCgatp1, PCgino1 and PCgscl were modest or weaker expression. Above seven promoters were further used to control the expression of xylose reductase gene from Neurospora crassa in C.glycerinogenes. Compared with 30°C, the xylitol yields of the seven recombinant strains were all improved at 42°C, and PCgcwp1 showed the highest xylitol production which was increased by 204% and reached 15.4g/L. These results showed a potential to high temperature fermentation on the stress tolerant C.glycerinogenes and some of novel high temperature inducible promoters.