作　　者： ; ; ; ; ; ; ;

机构地区： 同济大学环境科学与工程学院污染控制与资源化研究国家重点实验室

出　　处： 《环境科学学报》 2009年第9期1800-1805,共6页

摘　　要： 为了考察热处理后的重组DNA进入水环境后可能存在的环境风险,以pET-28b质粒为材料,以质粒相对转化效率为指标,考察了热变性重组质粒DNA的复性可能性,并在此基础上构建了人工模拟水环境系统,研究了热变性质粒DNA在水环境中的降解速率和影响因素.结果表明,热变性pET-28b质粒经过30min后,其转移活性可以得到恢复,在4～37℃之间,温度越高越有利于热变性质粒的复性.热处理过程中未被降解的质粒DNA进入水环境后,在pH值为7、8时降解速率相对较慢,在pH值为5、6、9的条件下,降解较快,但在任何pH下,1.0h后仍存在未降解的质粒DNA.水环境中的NaCl对热处理质粒DNA有一定的保护作用,而且这种作用是随着NaCl质量分数的提高而增强.进入水环境中的热变性DNA有足够的时间复性,从而可能发生基因转移.因此,这些热处理的质粒DNA进入环境后理论上存在一定的生态风险. Plasmid pET-28b was used as a test plasmid to investigate the potential environmental risk caused by thermo-treated recombinant DNA. Firstly, plasmid DNA transformation was performed to evaluate the re-naturation efficiency of the thermo-treated plasmid DNA, and then simulated aquatic environments were constructed to determine the persistence of un-decayed plasmid DNAs in the aquatic environment after thermo-treatment. The results showed that the transforming activity of the thermo-treated plasmid DNA could be recovered to a certain extent after re-naturing for 30 min. From 4 - 37℃, the higher the temperature, the more transforming activity of denatured plasmid DNA will be recovered. When thermo-treated plasmid DNAs were discharged into simulated aquatic environments with pH from 5 - 9, the persistence of un-decayed plasmid DNAs at pH 7 and 8 exceeded those at 5, 6 or 9, but at any pH some could persist for 1.0 h or more. Higher ionic strengths further inhibited decay of the recombinant plasmid in the simulated aquatic environment. These results indicate that recombinant DNAs which are not destroyed during the thermo-treatment process cannot be degraded completely in a short time in the aquatic environment, which means when they are discharged into aquatic environment, they may have enough time to re-nature and transform, thus resulting in gene diffusion.

关 键 词： 热处理 质粒 水环境 复性 转化 降解

领　　域： [环境科学与工程]