Abstract:In order to block biosynthesis genes aprF and aprG of apramycin in Streptomyces tenebrarius Tt-49,recombinant plasmid pFD10 was introduced to S.tenebrarius Tt-49 by conjugation.And double crossover mutant Tt-49 G53 was obtained finally.Preliminary research on physiological characteristics for double crossover mutant Tt-49 G53 was conducted.The results showed that double crossover mutant Tt-49G53 grew more slowly than parent strain,the level of antibiotic production was 13 u/mL,which was 100 times lower than the level of parent strain.The metabolic products were analyzed by TLC.A pre-judgment of the result was that double crossover mutant Tt-49 G53 couldn’t produce apramycin.It was supposed that aprF and aprG were not closely related to secondary metabolism of S.tenebrarius only,but also was associated with the growth and development of producing strain.
