Medium optimization for the production of anti-cyanobacterial substances by Streptomyces sp. HJC-D1 using response surface methodology.

Bioremediation using isolated anti-cyanobacterial microorganism has been widely applied in harmful algal blooms (HABs) control. In order to improve the secretion of activated anti-cyanobacterial substances, and lower the cost, a sequential optimization of the culture medium based on statistical design was employed for enhancing the anti-cyanobacterial substances production and chlorophyll a (Chl a) removal by Streptomyces sp. HJC-D1 in the paper. Sucrose and KNO3 were selected as the most suitable carbon and nitrogen sources based on the one-at-a-time strategy method, and sucrose, KNO3 and initial pH were found as major factors that affected the anti-cyanobacterial ability of the isolated stain via the Plackett-Burman design. Based on the response surface and canonical analysis, the optimum condition of culture medium was obtained at 22.73 g l(-1) of sucrose, 0.96 g l(-1) of KNO3, and initial pH 8.82, and the Chl a removal efficiency by strain HJC-D1 increased from 63 ± 2 % to 78 ± 2 % on the optimum conditions.