Effect Analysis of Mineral Salt Concentrations on Nosiheptide Production by Streptomyces actuosus.pdf

Molecules 2014, 19, 15507-15520; doi:10.3390/molecules191015507 molecules ISSN 1420-3049 /journal/molecules Article Effect Analysis of Mineral Salt Concentrations on Nosiheptide Production by Streptomyces actuosus Z-10 Using Response Surface Methodology Wei Zhou 1, Xiaohui Liu 2, Pei Zhang 3, Pei Zhou 4 and Xunlong Shi 4,* 1 Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China 2 College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, 333 Longteng Road, Shanghai 201620, China 3 CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China 4 School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, China * Author to whom correspondence should be addressed; E-Mail: xunlongshi@; Tel.: +86-21-5423-7431. External Editor: Nancy D. Turner Received: 21 July 2014; in revised form: 2 September 2014 / Accepted: 12 September 2014 / Published: 26 September 2014 Abstract: The objective of this study was to develop an optimal combination of mineral salts in the fermentation medium for nosiheptide (Nsh) production using statistical methodologies. A Plackett-Burman design (PBD) was used to evaluate the impacts of eight mineral salts on Nsh production. The results showed that among the no-significant factors, CaCO3, and K2HPO4·3H2O had positive effects, whereas FeSO4·7H2O, CuSO4·5H2O, and ZnSO4·7H2O had negative effects on Nsh production. The other three significant factors (Na2SO4, MnSO4·H2O, and MgSO4·7H2O) were further optimized by using a five-level three-factor central composite design (CCD). Experimental data were fitted to a quadratic polynomial model, which provided an effective way to determine the interactive effect of metal salts on Nsh production. The optimal values were determined to be 2.63, 0.21, and 3.37 g/L, respectively. The model also e