双胞胎儿童牙菌斑宏基因组文库构建

Construction of Metagenomic Library from Dental Plaque of Twin Children

目的：摸索构建口腔牙菌斑宏基因组文库的条件，为从口腔牙菌斑基因组中筛选耐酸基因奠定基础。方法：采用改进的SDS方法提取牙菌斑总DNA，用BamHI限制性内切酶部分酶切基因组DNA，以质粒pUC18为载体，转入大肠杆菌DH5α中。结果：最终构建了1对双胞胎儿童的两个宏基因组文库，文库白斑率达到90％，两个文库的克隆子均在1000个左右，文库质量检测重组率达到85．5％，插入片段大小集中在1．5～10kb之间。结论：从文库的白斑率、重组率和插入片段大小可以看出文库的质量较好，这为后续从文库中筛选新的耐酸基因奠定了良好的基础。

Objective.. To laid a foundation for obtaining new acid--tolerant genes from dental plaque by studying the conditions for constructing metagenomic libraries from dental plaque. Methods： In this study , dental plaque DNA was isolated using improved SDS method, digested by BamHI , integrated into pUC18 and then transformed into E. coli strain DH5a to construct metagenomic library. Results.. Two dental plaque metagenomic libraries were constructed, and each library contained about 1000 recombinants. Its leukoplakia rate was up to 90% and the re- combination rate was about 85.5 %. The size of the inserted fragments were between 2-10kb. Conclusion.. This re- search has laid a good foundation for the subsequent screening of acid-resistant genes from these libraries.