Microbial Degradation of Halogenated Compounds
Microbial Degradation of Halogenated Compounds
复制标题
卤代化合物的微生物降解
作者：
D. Ghosal;I. You;D. K. Chatterjee;A. M. Chakrabarty
本文研究了各种卤代化合物在分离纯培养物中的降解方式和降解基因的配置。在许多情况下，降解基因被发现聚集在质粒上，似乎处于阳性控制之下。体内遗传选择和体外遗传操作使得构建的菌株比天然菌株具有更广泛的生物降解潜力。在具有广泛宿主范围的载体中对卤化化合物的降解基因簇进行分子克隆也允许将这些基因转移到大量革兰氏阴性细菌中。2,4,5-三氯苯氧乙酸（2,4,5- t）降解微生物的应用已经证明了该菌株在短时间内从污染土壤中去除大量2,4,5-t的有效性，并且这种土壤已被证明支持通常对低浓度2,4,5-t敏感的植物的生长。在不久的将来必须解决的两个主要挑战是开发适当的微生物技术，以净化含有有害卤化化合物的土壤，以及颁布适当的法规，以确保在开放环境中应用遗传改良菌株期间公众的安全和福祉。
The mode of degradation of various halogenated compounds in isolated pure cultures and the disposition of the degradative genes have been studied. In many cases the degradative genes are found to be clustered on plasmids and appear to be under positive control. Genetic selection in vivo and genetic manipulations in vitro have allowed construction of strains having wider biodegradative potentials than their natural counterparts. Molecular cloning of the degradative gene clusters for halogenated compounds in vectors with a broad host range also allows the transfer of such genes to a large number of Gram-negative bacteria. The application of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degrading microorganisms has demonstrated the effectiveness of this strain in removing large amounts of 2,4,5-T from contaminated soil within a short period, and such soil has been shown to support the growth of plants normally sensitive to low concentrations of 2,4,5-T. The two major challenges that must be addressed in the near future are the development of appropriate microbial technology for the decontamination of soil containing hazardous halogenated compounds, and the promulgation of appropriate regulations to ensure the safety and well-being of the public during the application of genetically improved strains in an open environment.