Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
World J Microbiol Biotechnol. 2021 Jan 11;37(2):19. doi: 10.1007/s11274-020-02977-1.
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 1.2. and 1.6 times, respectively. Furthermore, overexpression of PDR3, which is known as a transcription factor involved in multi-drug resistance, effectively improved lactic acid tolerance in yeast. In addition, we clarified for the first time that high expression of PDR3 contributes to the improvement of lactic acid tolerance. PDR3 is considered to be an excellent target gene for studies on yeast stress tolerance and further researches are desired in the future.
虽然酵母酿酒酵母预计将被用作生产乳酸的宿主，但为了实现高效的非中和发酵，需要提高酵母的乳酸耐受性。在本研究中，我们通过先前开发的鸡尾酒δ整合策略优化了各种转录因子的表达水平，以提高酵母的乳酸耐受性。通过优化各种转录因子的表达水平，在非中和条件下，D-乳酸的最大产量和产率分别提高了 1.2 倍和 1.6 倍。此外，众所周知，多药耐药相关转录因子 PDR3 的过表达可有效提高酵母的乳酸耐受性。此外，我们首次阐明了 PDR3 的高表达有助于提高乳酸耐受性。PDR3 被认为是研究酵母应激耐受性的优秀靶基因，未来还需要进一步研究。
