ABSTRACT
In order to investigate the nutritional conditions of cephamycin biosynthesis independently of the biomass growth process, the nutrient limited-resting cell system was used. A replacement medium eliminating cell multiplication was developed. The presence of Mg2+, carbon source and nitrogen source was necessary for cephamycin production by resting cells of Streptomyces lactamdurans L 2/6. Maximum antibiotic production was obtained when maltose, saccharose, and fructose were used as carbon source, and L-asparagine as nitrogen source. An inhibitory effect on the process was exerted by the calcium ions. There was no visible inhibition of cephamycin biosynthesis by inorganic phosphate ions in concentration up to 100 mM.
Subject(s)
Cephamycins/biosynthesis , Streptomyces/metabolism , Asparagine/metabolism , Calcium/pharmacology , Carbon/metabolism , Culture Media , Fructose/metabolism , Magnesium/metabolism , Maltose/metabolism , Nitrogen/metabolism , Phosphates/metabolism , Streptomyces/growth & development , Sucrose/metabolismABSTRACT
During batch cultivation of Streptomyces lactamdurans a diauxic growth has been shown taking into consideration dry cell mass, protein, and DNA determination. This phenomenon was connected with substantial changes in environmental conditions such as concentrations of ammonia and amino nitrogen, soluble inorganic phosphate and pH. The antibiotic production was preceded by the preparatory phase occurring at the beginning of the second growth phase. A hypothetical pattern of cell physiology in the curse of cephamycin fermentation is discussed. An essential part in the biphasic cell growth and the induction of antibiotic synthesis in this model is played by phosphate depletion in the medium.
