Weightman A J, Don R H, Lehrbach P R, Timmis K N
Basic Life Sci. 1984;28:47-80. doi: 10.1007/978-1-4684-4715-6_4.
This paper reviews the genetic basis of haloaromatic biodegradation by bacteria, with a focus on the genetic analysis of Alcaligenes eutrophus JMP134, an organism which can utilize 3-chlorobenzoate, 2,4-dichlorophenoxyacetate (2,4-D) and related compounds as sole carbon and energy sources, and Pseudomonas sp. B13, a chlorobenzoate degrader. The involvement of transmissible plasmids pJP4 and pWR1, isolated from strains JMP134 and B13, respectively, in chloroaromatic mineralization has been examined, and restriction fragments of both plasmids have been cloned on the broad host range plasmid vector pKT231. Transposon Tn5 mutagenesis of these and other soil isolates enriched in and purified from mixed cultures utilizing 2,4,5-trichlorophenoxyacetate (2,4,5-T) as sole carbon and energy source, has been carried out using a "suicide" transposon donor, pLG221 (Co1Ibdrd-1::Tn5). Mapping of Tn5 insertions in mutants which accumulate pathway intermediates has facilitated the identification and cloning of genes encoding chlorocatechol 1,2-dioxygenase, and other key enzymes in haloaromatic catabolism. There are good prospects for the genetic construction of hybrid haloaromatic catabolic pathways by combining genes encoding broad specificity enzymes, capable of transforming halogenated analogues of their natural substrates, with genes for halocatechol degradation.
本文综述了细菌对卤代芳烃生物降解的遗传基础，重点是对真养产碱菌JMP134和假单胞菌属B13的遗传分析。真养产碱菌JMP134能够利用3-氯苯甲酸、2,4-二氯苯氧乙酸（2,4-D）及相关化合物作为唯一碳源和能源；假单胞菌属B13是一种氯代苯甲酸降解菌。分别从菌株JMP134和B13中分离得到的可转移质粒pJP4和pWR1参与氯代芳烃矿化作用的情况已得到研究，并且这两种质粒的限制性片段已被克隆到广泛宿主范围的质粒载体pKT231上。利用“自杀性”转座子供体pLG221（ColIbdrd-1::Tn5），对从以2,4,5-三氯苯氧乙酸（2,4,5-T）作为唯一碳源和能源的混合培养物中富集并纯化得到的这些及其他土壤分离菌株进行了转座子Tn5诱变。对积累途径中间产物的突变体中Tn5插入位点的定位有助于鉴定和克隆编码氯儿茶酚1,2-双加氧酶及卤代芳烃分解代谢中其他关键酶的基因。通过将编码能够转化其天然底物卤代类似物的广泛特异性酶的基因与卤代儿茶酚降解基因相结合，构建杂交卤代芳烃分解代谢途径具有良好的前景。
