Three successive extractions reduce quantification bias of microbial communities associated with incomplete DNA recovery in soil
3 次连续重复提取DNA 能较好反映土壤微生物丰度

Objective] To assess the quantification bias associated with incomplete extractions of soil microbial DNA and the feasibility of air-dried soil for microbial ecology study.Methods] The flooded rice soil and upland wheat soil were used,and multiple extractions of soil microbial DNA was performed by lysing a single sample for 5 successive times.The copy number of 16S rRNA and amoA genes of Archaea and Bacteria was quantified in each DNA extraction by real-time PCR.Results] Cumulative DNA yields in 3 successive extractions accounted for more than 76% of microbial DNA in soils,and more than 77.5% of gene copies could be recovered.Air-drying decreased the abundance of bacterial 16S rRNA gene and archaeal 16S rRNA gene by 90.3% and 12.5%,and the abundance of bacterial and archaeal amoA genes showed a decline by 81.2% and 84.3%,respectively.The decline showed similar trend in two soils,suggesting air-dried soil could be of choice for biogeographic survey of microbial communities.Conclusion] Three successive extractions of microbial DNA in soil could be of choice for microbial ecology study in order to reduce quantification bias associated with incomplete DNA recovery.Air-dried soil could be employed under certain circumstances,and further investigation is warranted for the underlying mechanism by which microbial communities manage to survive the desiccation of soil.