多功能农药降解基因工程菌株m-CDS-1环境释放安全评价

目的]为了评价多功能农药降解基因工程菌株m-CDS-1的环境释放中间试验水平的安全性.方法]通过农药检测、平板计数、Most probable number-PCR(MPN-PCR)和Denaturing Gradient GelElectrophoresis(DGGE)等方法在江苏大丰进行了工程菌株m-CDS-1田间降解农药效果、定殖动态和对土壤微生物群落结构影响的研究.结果]投加1.01×107CFU/g干土的工程菌株m-CDS-1在30 d时均能完全降解10.71 mg/kg的甲基对硫磷和1.29 mg/kg的呋喃丹.平板计数表明工程菌株m-CDS-1在土壤中快速下降;MPN-PCR检测结果显示,在4 d,15 d和30 d时,0～10 cm混合土壤中该工程菌株的数目分别为2.15±0.98×106CFU/g干土,3.70±4.66×106 CFU/g干土和检测不出.工程菌株m-CDS-1的投加不会对土壤可培养三大微生物菌群数量产生显著影响;基于细菌16S rDNA V3区的DGGE分析结果表明,施加农药对细菌菌落结构有显著影响,4 d,11 d,30 d时农药施用区与空白对照区的图谱相似性分别为17.16%,49.81%和75.01%,但到60 d时的相似性为98.62%.工程菌株m-CDS-1释放在前期对细菌群落结构有一定影响,4 d,11 d和30 d工程菌株释放区相对于空白的相似性分别为49.57%,38.30%和83.30%.在60 d时,空白、施药和施菌小区的图谱相似性都在90%以上.结论]工程菌株m-CDS-1不仅可同时高效降解甲基对硫磷和呋喃丹,仍保持了实验室内的原有特性,而且不会成为优势菌群长期在土壤环境中存在,也不会对土壤微生物群落结构造成长期影响.

Risk Assessment for Environmental Release of Genetically Engineered Mi-croorganism m-CDS-1

Abstract: Objective] To assess the environmental release risk of genetically engineered microorganism Sphingomonas sp. m-CDS-1. Methods] Pesticides detection, plates counting, most probable number-PCR (MPN-PCR) and denaturing gra-dient gel electrophoresis (DGGE) were used to study the pesticides degrading effects, the decline dynamics of m-CDS-1, and the effects of release of m-CDS-1 on community structure of soil microorganisms. Results] m-CDS-1 (1.01× 107CFU/g dry soil) could degrade both 10.71 mg/kg methyl parathion and 1.29 mg/kg carbofuran in 30 days. m-CDS-1 declined quickly with time, and could not be detected anymore in 30 days. Release of m-CDS-1 would not change the number of the cultivable microorganisms notably. The similarities of PCR-DGGE profiles between the pesti-cides applied treatments and the controls in 4, 11 and 30 days were 17.16 %, 49.81 % and 75.01 %, and the similarities between the m-CDS-1 released treatments and controls were 49.57 %, 38.3 % and 83.3 %, respectively. In 60 days, DGGE profiles of all treatments and controls had high similarities. Conclusion] m-CDS-1 could degrade both pesticides re-markably in the field, and would not be the predominant population, and would not affect the community structure of soil microorganisms in the long term.