studies on fermentation conditions of Bacillus cereus strain S1

The fermentation conditions of Bacillus cereus strain S1 producing a novel cyclic polypeptide (APS) were conducted by designs of single factor and orthogonal experiments.Factors such as temperature, initial pH, nitrogen sources, carbon sources etc. were studied. Two optimized fermentation media were as follows :wheat brown 5%, maize powder 5%, urea 0.2% and glucose 6%, NH 4NO 3 1.5%, Yeast extract 1.5%, NaCl 0.1%. The optimum temperature was 28℃ and the optimum initial pH was 6.8 or 7.4 . The transferred amount of oxygen had significant effects on the production of APS .