Enrichment of soymeal medium to increase the rapamycin production by streptomyces hygroscopicus

Research was carried out to study the improved and increased production of rapamycin by streptomyces hygroscopicus with soymeal enriched media. media containing soymeal produced rapamycin upto 82.89 mg/l. the medium was enriched with different additives that can interfere with biosynthesis process. l-tyrosine supplementations led to noticeable increase in the rapamycin production to 112 mg/l. however,the progress was achieved upon addition of the shikimic acid (precursor rapamycin moiety),where,it reached 160 mg/l. the greatest increase was recorded after addition of calcium superphosphate (cap) and the production achieved 176 mg/l. other substances like vitamins and trace elements had either no or negative effects on the biosynthesis of rapamycin. the study also showed the ability of low concentrations of calcium phosphate to replace the expensive large amount of shikimic acid.