Project description:It was found that after OA treatment, compared with the CK group, the abundance of lactic acid bacteria in the intestinal flora of mice in the OA group increased, and the increase in the abundance of lactic acid bacteria made the gene Il10 upregulated, Il10 had a significant effect on tumor volume reduction and prolongation of mouse survival, and played a role through cytokine receptor interaction pathway.
Project description:This study aimed to investigate the effects of oral administration of lactic acid bacteria (LAB) on gene expression in murine ileum. Two LAB strains, Lactococcus lactis subsp. lactis C59 and Lactobacillus rhamnosus GG, were administered to mice for 2 weeks. Microarray analysis was performed using total RNA from upper and lower ileum to detail the gene expression of 3 groups; control, C59-administered and GG-administered. Gene expression of upper ileum was less affected by administered strains than that of lower ileum and the latter was strain-specifically affected.
Project description:D-lactic acid is a three-carbon organic acid with a chiral structure and can improve the thermostability of polylactic acid. Microorganisms such as the methylotrophic yeast Pichia pastoris, which lack the natural ability to produce or accumulate high amounts of D-lactic acid, have been engineered to produce it in high titers. However, tolerance to D-lactic acid remains a challenge. In this study, we demonstrate that cell flocculation improves tolerance to D-lactic acid and leads to increased D-lactic acid production in Pichia pastoris. By incorporating a flocculation gene from Saccharomyces cerevisiae (ScFLO1) into P. pastoris KM71, we created a strain (KM71-ScFlo1) that demonstrated up to a 1.6-fold improvement in specific growth rate at high D-lactic acid concentrations. Furthermore, integrating a D-lactate dehydrogenase gene from Leuconostoc pseudomesenteroides (LpDLDH) into KM71-ScFlo1 resulted in an engineered strain (KM71-ScFlo1-LpDLDH) that can produce D-lactic acid at a titer of 5.12 0.35 g/L in 48 hours , a 2.6-fold improvement over the control strain lacking ScFLO1 expression. Transcriptomics analysis of this strain provided insights into the mechanism of increased tolerance to D-lactic acid including the upregulations of genes involved in lactate transport and iron metabolism. Overall, our work represents an advancement in the efficient microbial production of D-lactic acid by manipulating yeast flocculation.
