Exploration of the inhibitory mechanism of Lactobacillus plantarum on the production of BC by Bacillus plantarum: a metabolomics based approach

This study is based on the abnormal production situation of nata de coco factories. Multiple research methods are used to compare and analyze abnormal fermentation broth and normal fermentation broth. Non-bacterial cellulose (BC)-producing bacteria were isolated from abnormal fermentation broth. The isolated strains were mixed with Komagataeibacter nataicola to explore the mechanism of production inhibition. The results showed that there was a significant difference in the structure of BC between the abnormal group and the normal group. The composition of microbial community in the abnormal group was more abundant than that in the normal group. The microorganisms in the normal group are mainly composed of Komagataeibacter, followed by Vibrionimonas and Lactobacillus. The microorganisms in the abnormal group are mainly composed of Lactiplantibacillus, Acetobacter, Lactobacillus, Leuconostoc and a small amount of Komagataeibacter. The difference of flora composition showed that non-BC-producing bacteria may have a negative effect on the process of BC production. Six Lactiplantibacillus strains were isolated from the fermentation broth of abnormal group, all of which inhibited the production of BC by JF6211(Komagataeibacter). When GPb4103 and JF6211 were co-cultured, the contents of some metabolites in the system were lower than those in the control group, such as D-Threitol, arabinitol, mannitol, propylene glycol, ascorbate, propionate, taurine, acetoin, carnitine, UDP-Glucose, ethanol. The contents of glucose-1-phosphate, lactate and threonine were higher than those in the control group. The biological metabolic pathway of JF6211 is affected by GPb4103. The pathway of UDP-Glucose synthesis was inhibited by the metabolites of GPb4103, which reduced the number of UDP-Glucose. The ability of JF6211 to synthesize BC was weakened. GPb4103 will also reduce the ethanol content in the system, thus reducing the yield of BC.