RESPONSE-SURFACE ANALYSIS OF CHLORTETRACYCLINE AND TETRACYCLINE PRODUCTION WITH K-CARRAGEENAN IMMOBILIZED STREPTOMYCES-AUREOFACIENS

A full-factorial experimental design at three levels with two independ ent variables, carrageenan concentration (1.0, 1.5, and 2.0%) and pota ssium chloride concentration (0.3, 0.7, and 1.1 M) was studied in orde r to analyze the effect of both factors on the antibiotic production o f K-carrageenan-immobilized mycelia of Streptomyces aureofaciens. The response surfaces obtained have indicated that both carrageenan and po tassium chloride concentrations have a pronounced effect on the yield of chlortetracycline (CTC) and tetracycline (TC) produced by S. aureof aciens. By exclusively varying the immobilization conditions, the tetr acycline production can be enhanced more than eight times (12.3 mg g(- 1) biomass for immobilized cells vs. 1.5 mg g(-1) biomass for free cel ls) in comparison with free-cell mycelial cultures. (C) 1997 Elsevier Science Inc.