DEGRADATION OF MONOHALOGENATED, DIHALOGENATED, AND TRIHALOGENATED BENZOIC-ACIDS BY PSEUDOMONAS-AERUGINOSA JB2
DEGRADATION OF MONOHALOGENATED, DIHALOGENATED, AND TRIHALOGENATED BENZOIC-ACIDS BY PSEUDOMONAS-AERUGINOSA JB2
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DOI：
10.1128/aem.56.12.3842-3850.1990
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发表时间：
1990-12-01
影响因子：
4.4
通讯作者：
FOCHT, DD
中科院分区：
文献类型：
--
作者：
HICKEY, WJ;FOCHT, DD
以2-氯苯甲酸为唯一碳源，通过富集培养从多氯联苯污染土壤中分离到铜绿假单胞菌JB2。随后发现菌株JB2也生长在3-氯苯甲酸酯、2，3-和2，5-二氯苯甲酸酯、2，3，5-三氯苯甲酸酯以及其他一卤代和二卤代苯甲酸上。还观察到了2，4-二氯苯甲酸酯的共代谢。氯代儿茶酚是所有氯苯甲酸酯分解代谢途径的中心中间体。2-氯苯甲酸酯的降解是通过3-氯代儿茶酚进行的，而4-氯代儿茶酚是从2，3-二氯苯甲酸酯和2，5-二氯苯甲酸酯的代谢中鉴定出来的。最初对氯苯甲酸酯的攻击依赖于氧气，很可能是由双加氧酶介导的。虽然在菌株JB2中没有检测到质粒，但在70%的甘油培养菌落中检测到了自发突变。突变株的表型均为：苯甲酸+，3-氯苯甲酸+，2-氯苯甲酸-，2，3-二氯苯甲酸-，2，5-二氯苯甲酸-。虽然氯代儿茶酚在野生型水平上被突变体氧化，但2-氯-以及2，3-和2，5-二氯苯甲酸酯的氧化作用显著减弱。这些结果表明，菌株JB2除具有苯甲酸双加氧酶外，还具有降解邻位取代氯苯甲酸酯所必需的卤代苯甲酸双加氧酶。
Pseudomonas aeruginosa JB2 was isolated from a polychlorinated biphenyl-contaminated soil by enrichment culture containing 2-chlorobenzoate as the sole carbon source. Strain JB2 was subsequently found also to grow on 3-chlorobenzoate, 2, 3- and 2,5-dichlorobenzoates, 2,3,5-trichlorobenzoate, and a wide range of other mono- and dihalogenated benzoic acids. Cometabolism of 2,4-dichlorobenzoate was also observed. Chlorocatechols were the central intermediates of all chlorobenzoate catabolic pathways. Degradation of 2-chlorobenzoate was routed through 3-chlorocatechol, whereas 4-chlorocatechol was identified from the metabolism of both 2,3- and 2,5-dichlorobenzoate. The initial attack on chlorobenzoates was oxygen dependent and most likely mediated by dioxygenases. Although plasmids were not detected in strain JB2, spontaneous mutants were detected in 70% of glycerol-grown colonies. The mutants were all of the following phenotype: benzoate+, 3-chlorobenzoate+, 2-chlorobenzoate-, 2,3-dichlorobenzoate-, 2,5-dichlorobenzoate-. While chlorocatechols were oxidized by the mutants at wild-type levels, oxidation of 2-chloro- and 2,3- and 2,5-dichlorobenzoates was substantially diminished. These findings suggested that strain JB2 possessed, in addition to the benzoate dioxygenase, a halobenzoate dioxygenase that was necessary for the degradation of chlorobenzoates substituted in the ortho position.