泰洛星产生菌弗氏链霉菌变株TM4-180的生物学特性

BIOLOGICAL PROPERTIES OF TM4-180 MUTANT DERIVED FROM TYLOSIN PRODUCERS TREPTOMYCES A41

本文报道泰洛星产生菌弗氏链霉菌诱变株的生物学特性:(1)变株TM4—180是弗氏链霉菌(StrePtomyces fradiae)A41多次诱变衍生的产生泰洛星并对泰洛星有高抗性(Tyl^+Tyl^r)的变株,其泰洛星产量是原始菌种A41的18倍。(2)用紫外线、亚硝基胍和光敏诱变剂等诱变剂做菌种诱变,效果很好。筛选的Tyl^+Ty1~r菌株,如TM1-32、TM4—180等产生抗生素的能力为直接亲株的160～200％。(3)TM4-180经γ—射线处理获得阻断变株TM5-221、TM5—257,它们不产生泰洛星,但其发酵时能产生泰洛星,其效价是单独发酵的10～20倍。(4)TM5—257(Tyl^-Tyl^r)用紫外线处理得变株TM5-257-60,它是泰洛星生物合成的回复突变株,具有隔代亲株TM4-180的相同功能。(5)变株TM4-180及有关菌株(Tyl^r)对泰洛星具有抗性,在含5～10mg/ml的培养基中正常生长。而TM5—221等变株Tyl^3)对泰洛星敏感,可能泰洛星抗性基因tlr C缺失。抗药标记的变化,是DNA突变多样性的表现。

The mutant TM4-180 was derived from StrePtomyces fradiae A41 and produced tylosin about 18 times of that produced by A41, a wild type parent. TM4 -180 and the relative strains were treated with UV, NTG, and Trioxsalen for inducing mutation to produce high level of tylosin and selfresistmty. TM5-221 and TM5-257 are tylosin non-producer blocked-mutant which survived from gamma-ray treatment, but they could cosynthesis tylosin. TM4 -180 and the relative strains (Tyl+Tyl5) have high degree of self-resistivity. The mutant TM4 -180 and the derived strain are valuable material for the use of biochemical and recombimant DNA techniques in tylosin biosynthesis and resistance studies.