Yeast Extract Inhibits Prodigiosin Production and Promotes Serrawettins Production in Serratia marcescens

Serratia marcescens is a gram-negative bacterium, which can produce many metabolites, among which the study of prodigiosin is the most extensive. This experiment explored the effect of yeast extract on intracellular metabolic pathway in S. marcescens. The experimental results showed that yeast extract could inhibit the production of prodigiosin in S. marcescens to a considerable extent. It was verified by RT-qPCR that yeast extract inhibited the expression of genes in the synthesis pathway of prodigiosin. However, although there was no production of prodigiosin in the fermentation broth added with yeast extract, a large number of lipopeptide serrawettins was produced through preliminary detection and identification. Serrawettins have surface activity, antibacterial and antitumor activity. Therefore, the addition of yeast extract can be used to promote the production of serrawettins by S. marcescens. There was no report on the effect of yeast extract on intracellular metabolic pathway in S. marcescens in other literatures at present.