Improved Tolerance of Lactiplantibacillus plantarum in the Presence of Acid by the Heterologous Expression of trxA from Oenococcus oeni

Oenococcus oeni is the main microorganism that undergoes malolactic fermentation (MLF) in winemaking industry due to its excellent adaptability harsh wine environments. The start of MLF often delayed or even fails, and low pH appears be a crucial parameter. To study function trxA gene acid stress, plasmid containing O. SD-2a was heterologously expressed Lactiplantibacillus plantarum WCFS1. recombinant strain (WCFS1-trxA) grew better than control (WCFS1-Vector) under stress. expression thioredoxin system genes much higher compared with In addition, series physiological biochemical assays were conducted. ATP content lower strain, while cell membrane fluidity integrity improved strain. Moreover, reactive oxygen species (ROS) accumulation, intracellular GSH level, superoxide dismutase (SOD) activity showed decreased accumulation by improving SOD activity. conclusion, heterologous improves L. WCFS1, reducing bacterial ROS increasing integrity, enhancing tolerance WCFS1