College of Enology, Northwest A & F University, Yangling, China.
Shandong Engineering and Technology Research Center for Ecological Fragile Belt of Yellow River Delta, Binzhou, China.
FEMS Microbiol Lett. 2019 Aug 1;366(15). doi: 10.1093/femsle/fnz192.
Oenococcus oeni is a lactic acid bacterium that is widely used in wine-making to conduct malolactic fermentation (MLF). During MLF, O. oeni undergoes acid and ethanol stress that impairs its growth. In order to investigate the role that the ctsR gene plays in acid-ethanol stress, the ctsR gene from O. oeni was expressed heterologously in Lactobacillus plantarum. The transcription level of the ctsR gene and 10 additional stress response genes in L. plantarum were analyzed by RT-qPCR. Physiological assays to assess reactive oxygen species accumulation, cell membrane integrity, intracellular ATP and GSH levels, Ca2+/Mg2+-ATPase and Na+/K+-ATPase activities were also performed. Results showed that the recombinant strain WCFS1-CtsR exhibited stronger growth performance than the control strain WCFS1-Vector, and the expression of ctsR, clp and hsp genes were significantly increased under acid-ethanol stress. Furthermore, WCFS1-CtsR displayed 1.08- and 1.39-fold higher ATP and GSH concentrations, respectively, compared with the corresponding values for WCFS1-Vector under acid-ethanol stress. ROS accumulation and PI value of WCFS1-CtsR were decreased by 46.52 and 42.80%, respectively, compared with the control strain. In addition, the two ATPase activities in WCFS1-CtsR increased significantly compared with WCFS1-Vector. This is the first report demonstrating that ctsR gene enhances the acid-ethanol tolerance of L. plantarum.
酒香酵母是一种广泛应用于葡萄酒酿造中的乳酸菌，用于进行苹果酸-乳酸发酵（MLF）。在 MLF 过程中，酒香酵母会经历酸和乙醇胁迫，这会损害其生长。为了研究 ctsR 基因在酸-乙醇胁迫中的作用，将来自酒香酵母的 ctsR 基因在植物乳杆菌中异源表达。通过 RT-qPCR 分析了植物乳杆菌中 ctsR 基因和另外 10 个应激反应基因的转录水平。还进行了生理测定以评估活性氧（ROS）积累、细胞膜完整性、细胞内 ATP 和 GSH 水平、Ca2+/Mg2+-ATP 酶和 Na+/K+-ATP 酶活性。结果表明，重组菌株 WCFS1-CtsR 的生长性能强于对照菌株 WCFS1-Vector，在酸-乙醇胁迫下 ctsR、clp 和 hsp 基因的表达显著增加。此外，与对照菌株 WCFS1-Vector 相比，在酸-乙醇胁迫下，WCFS1-CtsR 的 ATP 和 GSH 浓度分别提高了 1.08 倍和 1.39 倍。与对照菌株相比，WCFS1-CtsR 的 ROS 积累和 PI 值分别降低了 46.52%和 42.80%。此外，与 WCFS1-Vector 相比，WCFS1-CtsR 中的两种 ATP 酶活性显著增加。这是首次报道 ctsR 基因增强了植物乳杆菌的酸-乙醇耐受性。
