it is well known that more than 90 % of the microorganisms existing in nature are refractory to selective enrichment cultures . to overcome these drawbacks, molecular biological techniques especially 16s rdna analysis are increasingly employed in the analysis of microorganisms in their natural habitats 目前已知,自然環(huán)境中的微生物有90-99是還未能培養(yǎng),為了克服上述缺點(diǎn),分子生物學(xué)技術(shù)尤其是16srdna分析的方法引入土壤微生物群落的分析。