Artificial induction of the UPR by Tet-off system-dependent expression of Hac1 and its application in Saccharomyces cerevisiae cells.

In response to endoplasmic reticulum (ER) stress, yeast Saccharomyces cerevisiae cells produce Hac1, which is a transcription factor responsible for the unfolded protein response (UPR). When Hac1 is unregulatedly expressed from a constitutive promoter, the ER is artificially enforced and enlarged, even without ER stress stimuli. However, such cells are unsuitable for applicative bioproduction because they grow quite slowly and quickly lose their high-UPR phenotype upon their long-term storage.

domination during the fermentation of Japanese traditional fermented fish (funazushi).

Funazushi is a Japanese traditional fermented fish made with boiled rice without the addition of microbial starter cultures. Isolates from various commercial funazushi products, as identified by 16S rDNA sequences, suggested that strains are major lactic acid bacteria. Based on an analysis of the putative CRISPR (clustered regularly interspaced short palindromic repeat) region, the genetic diversity of strains was examined.