Improvement of lactic acid tolerance by cocktail δ-integration strategy and identification of the transcription factor PDR3 responsible for lactic acid tolerance in yeast Saccharomyces cerevisiae.

Although, yeast Saccharomyces cerevisiae is expected to be used as a host for lactic acid production, improvement of yeast lactic acid tolerance is required for efficient non-neutralizing fermentation. In this study, we optimized the expression levels of various transcription factors to improve the lactic acid tolerance of yeast by a previously developed cocktail δ-integration strategy. By optimizing the expression levels of various transcription factors, the maximum D-lactic acid production and yield under non-neutralizing conditions were improved by 1.

Modulation of gene expression by cocktail δ-integration to improve carotenoid production in Saccharomyces cerevisiae.

Carotenoids, including β-carotene, are commercially valuable compounds, and their production by engineered Saccharomyces cerevisiae is a promising strategy for their industrial production. Here, to improve β-carotene productivity in engineered S. cerevisiae, a cocktail δ-integration strategy, which involves simultaneous integration of various multi-copy genes, followed by selection of desirable transformants, was applied for modulation of β-carotene production-related genes expression.