Effects of NTH1 gene deletion and overexpressing TPS1 gene on freeze tolerance in Baker's Yeast

The content of trehalose is widely believed to be a major determinant of stress resistance in Saccharomyces cerevisiae. A neutral trehalase gene, NTH1, is involved in trehalose degradation and TPS1 encoding trehalose biosynthesis enzyme is improtant to trehalose accumulation in S. cerevisiae. In this research, the responses of two engineering strains, the deletion of NTH1 (Delta nth1) and overexpression TPS1 (Delta nth1 + TPS1), were investigated to freezing stresses. High trehalose accumulation and growth activity were observed in Delta nth1 + TPS1 strain after freezing stress induction. Our results indicated that high trehalose accumulation can make yeast cells resistant freezing stress.