棒状链霉菌(Streptomyces clavuligerus)可产生多种β-内酰胺类化合物,其中包括克拉维酸。利用聚合酶链式反应(PCR)-Targeting体系构建棒状链霉菌突变株是获得克拉维酸高产菌株的又一可行方法。采用该体系对棒状链霉菌的lat基因进行了敲除,获得了没有抗性标记的lat基因被敲除的突变株S.clavuligerus lat::scar,其克拉维酸产量是出发菌株的2.8倍。由于最终构建的突变株没有抗性标记,因此可以将该方法应用于突变棒状链霉菌的其他基因,实现用一种抗性标记突变同一菌株不同基因的目的,为链霉菌的基因突变提供了又一种有效的方法。

Streptomyces clavuligerus(S.clavuligerus) produces a number of β-lactam compounds,including clavulanic acid.An efficient procedure for creating clavulanic acid high producing S.clavuligerus mutant by using the polymerase chain reaction(PCR)-targeting system was described.PCR-targeting system was applied to mutate the lat gene of S.clavuligerus to obtain lat gene knocked-out,unmarked mutant S.clavuligerus lat:scar.Through PCR-targeting system to knock out the lat gene of S.clavuligerus,clavulanic acid of the mutant S.clavuligerus lat:scar was 2.8-fold to the original strain.This procedure allows repeated use of the same resistance marker for making multiple knock-outs in the same strain.This provides another efficient procedure for creating Streptomyces mutants.