The Culture Medium Optimization of Serratia plymuthica UBCF_13 To Produce Antifungal Compounds

Abstract

Abstract Bacteria can produce secondary metabolites compounds that act as antifungal agents. But in natural conditions, the production of secondary metabolites is low and requires certain growth conditions. One of the methods to increase secondary metabolites production is the modification of the culture medium. In this study, four environmental factors combination was used to optimize the optimal culture medium for S. plymuthica UBCF_13 to produce antifungal compounds. The environmental factors were pH 8, 2 % peptone, 1 mM MnSO4, and 8 hours culture duration. In inhibitory activity test to C. gloeosporioides fungi, cell-free supernatant and cell culture of S. plymuthica UBCF_13 were applied. The results showed that the highest inhibitory activity of cell-free supernatant application (17.80%) was obtained from a medium that adjusted with pH 8, 1 mM MnSO4, and 8 hours duration. While the highest inhibitory activity of cell culture application (44.53%) was obtained from the medium with a combination of pH 8, 2% peptone, 1 mM MnSO4, and 8 hours culture duration. In the SDS-PAGE visualization, 4 protein bands appeared which were thought to be closely related to the inhibitory activity of antifungal compounds of S. plymuthica UBCF_13. The optimum medium was found to be a medium with a combination of pH 8, 2% peptone, 1mM MnSO4, and 8 hours of culture duration.