Abstract:The acid accumulation caused by carbon metabolism seriously affects the metabolic activity of microbial cells. In order to improve acid tolerance of cells, the acid tolerance of recombinant strain was studied by overexpression of the thiamine transporter ThiT. Based on this, comparative and recombinant strains were studied by comparative transcriptomics. We found that the survival rate of recombinant strain was 2.4 times higher than that of the control strain after 3 h of treatment with acid stress (pH 4.0). Transcriptomic analysis found that overexpression of the ThiT transporter increases the ability of cells to transport carbohydrates, thereby providing more energy for the cells against acid stress tolerance. In addition, significant upregulation of oligopeptides, betaine and other related transporters can help cells resist the damage of acid stress. The authors explored the specific mechanism of ThiT transporter in Lactococcus lactis to increasee tolerance of cellular acid stress. This study provided a theoretical basis for the application of ThiT protein in other industrial microorganisms.
