Abstract: In order to explore new methods to improve the yield of polymyxin E， five different carbon sources including glucose， sucrose， maltose， lactose and soluble starch were added in the fermentation medium， respectively. The influence on Paenibacillus polymyxa growth and polymyxin E production of different carbon sources were investigated through plate counting method and HPLC method. The results indicated that the effects of different carbon sources on the growth of Paenibacillus polymyxa and the polymyxin E production varied significantly. The effect of these carbon sources on polymyxin E production was: soluble starch>lactose>sucrose>maltose>glucose. Soluble starch promoted both cell growth and polymyxin E yield by extending the polymyxin E biosynthetic period and promoting the synthetic rate. Compared with glucose as carbon source, the yield and the synthetic rate of polymyxin E were increased by 111% and 60%， respectively. Therefore， soluble starch was the optimal candidate for carbon sources among the five carbohydrates in polymyxin E synthese.

Key words: Paenibacillus polymyxa, polymyxin E, carbon source, soluble starch