一种土壤微生物总DNA的高效提取方法

AN EFFICIENT METHOD FOR DNA EXTRACTION FROM SOIL MICROORGANISM

获得高浓度、大片段、多样性程度高的土壤微生物总DNA 是研究土壤微生物群落结构的分子生态学基础。本文采用间接法(菌体细胞回收法)提取红壤地区两种土壤类型的土壤微生物总DNA,定量计算其回收率,并与直接法(细胞原位裂解法)比较了提取效率和纯度。结果表明:红壤地区2种土壤每克干土的总DNA提取量,间接法约为0.34和0.53礸/g干土,直接法约为13.62和24.32礸/g干土;间接法的提取效率低于直接法,但所得DNA片段较大,且Sau 3AⅠ 酶切和16 S rDNA通用引物PCR扩增结果显示,间接法比直接法更能有效地去除土壤中的某些抑制剂,所得总DNA的纯度更高,有利于后续操作。

Isolation of DNA sufficient in purity, large in fragment and high in diversity from natural environments is the basis for molecular ecology study on community structure. In this study, the authors chose an indirect method, which is the cell recovery method, to extract DNA from two distinct red soils in South China, calculate its recovery efficiency and compare with the direct method in DNA yield and purity. The results show that the crude DNA yields from the two soils were about 0.34 and 0.53礸/g by the indirect method and 13.62礸, and 24.32礸/g dried soil by the direct method respectively. Although the indirect DNA extraction method recovered smaller amounts of total DNA than the direct method, the DNA fragments are larger in size. Moreover, the results of Sau3AⅠenzyme digestion and PCR amplification in evaluating DNA purity demonstrate that the indirect method can delete some inhibitor more efficiently, yielding DNA of superior quality more suitable for follow-up procedures.