中文摘要：

提出直接从环境河流底泥和表层水体中同时提取不同形态DNA（胞内、胞外、染色体和质粒DNA）的有效方法.利用该方法提取了海河典型区域底泥的胞外DNA和胞内DNA及水体中细菌染色体DNA和质粒DNA.结果表明,NaH2PO4提取的胞外DNA分子量大于1kb,提取率40%～72%,没有共提取胞内DNA.胞内DNA提取的分子量均大于23.1kb,细菌质粒DNA与染色体DNA同时分离.16SrDNA与sul2扩增验证提取方法可靠性.16SrDNA扩增结果显示所有胞外DNA呈阴性,胞内DNA呈阳性.质粒DNA和染色体DNA的16SrDNA扩增显示,染色体DNA结果显阳性,质粒DNA呈阴性,sul2的结果相反.

英文摘要：

In this paper,effective methods were presented to extract different gene types（extracellular DNA,intracellular DNA,genome DNA and plasmid DNA）from the sediments and water in environment.The methods were used for extracted extracellular DNA and intracellular DNA in sediments while genome DNA and plasmid DNA of bacteria in water in typical regions of Haihe River.Results showed that extracellular DNA was more than 1kb in size;its recovery ratio was 46%～72% without containing intracellular DNA by using NaH2PO4.All intracellular DNA were more than 23.1kb in size.Genome DNA and plasmid DNA were separated simultaneously.PCR amplification of 16S rDNA and sul2 were applied for assurance of the methods.Results showed that products of 16S rDNA of all the extracellular were negative while intracellular DNA positive.The genome DNA amplified of 16S rDNA turned out to be positive while of sul2 was negative,the results of plasmid DNA were the opposite.