Park Won-Kun, Yang Ji-Won, Kim Hyun-Soo
Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 350-701, Korea.
J Ind Microbiol Biotechnol. 2015 Apr;42(4):567-75. doi: 10.1007/s10295-015-1584-y. Epub 2015 Jan 23.
Saccharomyces cerevisiae strains tolerant to salt stress are important for the production of single-cell protein using kimchi waste brine. In this study, two strains (TN-1 and TN-2) tolerant of up to 10 % (w/v) NaCl were isolated by screening a transposon-mediated mutant library. The determination of transposon insertion sites and Northern blot analysis identified two genes, MDJ1 and VPS74, and revealed disruptions of the open reading frame of both genes, indicating that salt tolerance can be conferred. Such tolerant phenotypes reverted to sensitive phenotypes on the autologous or overexpression of each gene. The two transposon mutants grew faster than the control strain when cultured at 30 °C in rich medium containing 5, 7.5 or 10 % NaCl. The genes identified in this study may provide a basis for application in developing industrial yeast strains.
耐盐胁迫的酿酒酵母菌株对于利用泡菜废盐水生产单细胞蛋白具有重要意义。在本研究中，通过筛选转座子介导的突变体文库，分离出了两株耐高达10%（w/v）NaCl的菌株（TN-1和TN-2）。转座子插入位点的确定和Northern印迹分析鉴定出两个基因，MDJ1和VPS74，并揭示了这两个基因开放阅读框的破坏，表明可以赋予耐盐性。当每个基因自体表达或过表达时，这种耐受表型恢复为敏感表型。在含有5%、7.5%或10% NaCl的丰富培养基中于30°C培养时，这两个转座子突变体比对照菌株生长得更快。本研究中鉴定出的基因可能为开发工业酵母菌株的应用提供基础。
