MAL62 overexpression and NTH1 deletion enhance the freezing tolerance and fermentation capacity of the baker's yeast in lean dough.

Background: Trehalose is related to several types of stress responses, especially freezing response in baker's yeast (Saccharomyces cerevisiae). It is desirable to manipulate trehalose-related genes to create yeast strains that better tolerate freezing-thaw stress with improved fermentation capacity, which are in high demand in the baking industry.

Results: The strain overexpressing MAL62 gene showed increased trehalose content and cell viability after prefermention-freezing and long-term frozen. Deletion of NTH1 in combination of MAL62 overexpression further strengthens freezing tolerance and improves the leavening ability after freezing-thaw stress.

Conclusions: The mutants of the industrial baker's yeast with enhanced freezing tolerance and leavening ability in lean dough were developed by genetic engineering. These strains had excellent potential industrial applications.