| Bacillamide C was isolated from the bacterium Bacillus atrophaeus C89, associated with the South China Sea sponge Dysidea avara. Members of Bacillamides family possess antialgal activity. In order to improve the production of Bacillamide C, statistical methods were applied to optimize the medium components in the 250ml shake flask. Then in the 5L-fermenter, fed-batch culture was preliminary studied.Based on the establishment of HPLC analysis of Bacillamide C, the target was achieved as following steps. Firstly, a better medium was chosen as the basic medium from 4 different mediums for the higher yield of Bacillamide C. Secondly, three precursors (Trp, Cys, Ala) were proved to have remarkable effects on Bacillamide C production and their concentration and added time were determined by single factor experiment. Thirdly, Plackett-Burman design was used for the initial optimization, and seven factors viz., corn starch, soy peptone, peptone, CaCO3, L-Tryptophan, L-Cysteine and L-α-Alanine were selected for this study. Finally, four significant factors (corn starch, CaCO3, L-Cysteine and L-α-Alanine) were selected to test the effect on the Bacillamide C production using Box-Bohnken response surface methodology. The optimal fermentation parameters for enhanced Bacillamide C yield were found to be: corn starch 3.64g/L, peptone 6.0g/L, soy peptone 4.0g/L, CaCO3 6.29g/L, L-Cysteine 0.10g/L, L-Tryptophan 0.02g/L, dissolved in artificial sea water(Cys and Trp were added after 40h of the plateau).The optimal culture conditions in the 250ml shake flask led to a Bacillamide C yield of 22.797mg/L, which was 8.3-fold than that of the basic medium.Bacillamide C production was scaled up to the 5L-fermenter scale with the optimized medium in the shake flask (250ml). Firstly, the pH level was optimized as pH 7.7. Then two fed-batch time points (16.5h, 24h) were investigated. Finally, the maximum Bacillamide C concentration in the 5L-fermenter was 70.85mg/L with the fed-batch time 24h.
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