Beta-lactam and aminoglycoside production from streptomycetes

Streptomyces cattleya, S. fradiae and S. griseus produced different amounts of growth when cultured sequentially through sporulation, vegetative and antibiotic production media. Only S. griseus grew well on all three types of medium. Streptomyces cattleya grew poorly on both sporulation and vegetative media. Growth was 1.6 and 8.0 mg/1/h respectively. For all three species, biomass yield in the final antibiotic production medium was dependent on amount of inoculum. Antibiotic yields were obtained only from production media. Under slow growth conditions L-cysteine and L-valine supplementation stimulated S. cattleya beta-lactam production, giving 1000 micrograms/ml beta-lactam equivalents compared with 45 micrograms/ml beta-lactam equivalents for no supplementation. For aminoglycosides the agar well diffusion bioassay was more sensitive towards the hydrochloride than the neutral salt. Paper chromatography confirmed the main antibiotic classes. RF values for replicate samples indicated aminoglycoside homogeneity and beta-lactam heterogeneity.