The Cell-cell Communication And Enhanced Production In The Second Step Fermentation Of Vitamin C

The two-step fermentation process invited by prof. Yin of China was widelyused to produce vitamin C. Bacillus megaterium and Ketogulonigenium vulgare usedin the second step fermentation were mixed cultured to produce2-keto-gulonic acidwhich was the precursor of vitamin C. Although the yield significantly was higherthan other methods, their cell-cell communication, especially the role of K. vulgare inthis interaction was still not clarified. Metabolomics, a high-throughput systemsbiology approach, was used in this study to analyze different states in the mixedfermentation process. It was found that Bacillus megaterium swarm along the trace ofK.vulgare when they separated from the culture reaches a specific value in themeantime distance on solid medium. By analyzing chemical composition inside andoutside the cells, it was found that K.vulgare accumulated nutrients outside the cells,which attract the directed movement of B.megaterium. On the other hand,B.megaterium accumulated erythritol and other substances outside the cells alsopromoted K.vulgare to produce2-keto gulonic acid. Pyridine carboxylic acid in themixed culture also suggested the sporulation of B.megaterium. Metabolomics resultsshow different periods in industrial processes, presents lots of trends of metabolitecontent in the mixed culture system, suggesting a variety of physiological processesoccured, especially some changed with pyridine carboxylic acid. Based on theseresults above, the study found that thiol compounds, including glutathione (GSH) ordithiothreitol (DTT), could significantly promote the2-keto-gulonic acid productionand growth of K.vulgar when it was cultured alone. And metabolomics researchresults show that the content of amino acids and pentose phosphate pathwaymetabolic intermediate thiols added metabolite concentration levels have increasedsignificantly, and its content changes and thiols have substance has a certain degree ofcorrelation.