Appl Environ Microbiol. 1997 May;63(5):1974-9. doi: 10.1128/aem.63.5.1974-1979.1997.
The degradation of toluene by Pseudomonas putida F1 and of chlorobenzenes by Burkholderia sp. strain PS12 is initiated by incorporation of dioxygen into the aromatic nucleus to form cis-dihydrodihydroxybenzenes. Toluene-grown cells of P. putida F1 and 3-chlorobenzoate-grown cells of Burkholderia sp. strain PS12 were found to monooxygenate the side chain of 2- and 3-chlorotoluene to the corresponding chlorobenzyl alcohols. Further metabolism of these products was slow, and the corresponding chlorobenzoates were usually observed as end products, whereas the 3-chlorobenzoate produced from 3-chlorotoluene in Burkholderia sp. strain PS12 was metabolized further. Escherichia coli cells containing the toluene dioxygenase genes from P. putida F1 oxidized 2- and 3-chlorotoluene to the corresponding chlorobenzyl alcohols as major products, demonstrating that this enzyme is responsible for the observed side chain monooxygenation. Two methyl- and chloro-substituted 1,2-dihydroxycyclohexadienes were formed as minor products from 2- and 3-chlorotoluene, whereas a chloro- and methyl-substituted cyclohexadiene was the only product formed from 4-chlorotoluene. The toluene dioxygenase of P. putida F1 and chlorobenzene dioxygenase from Burkholderia sp. strain PS12 are the first enzymes described that efficiently catalyze the oxidation of 2-chlorotoluene.
恶臭假单胞菌 F1 降解甲苯和伯克霍尔德氏菌 PS12 菌株降解氯苯是通过将氧气掺入芳香核中形成顺式-二氢-二羟基苯来启动的。发现甲苯生长的恶臭假单胞菌 F1 细胞和 3-氯苯甲酸生长的伯克霍尔德氏菌 PS12 菌株将 2-和 3-氯甲苯的侧链单加氧酶化为相应的氯苄醇。这些产物的进一步代谢缓慢，通常观察到相应的氯苯甲酸盐作为终产物，而从 Burkholderia sp. PS12 中的 3-氯甲苯产生的 3-氯苯甲酸进一步代谢。含有恶臭假单胞菌 F1 的甲苯双加氧酶基因的大肠杆菌细胞将 2-和 3-氯甲苯氧化为主要产物的相应氯苄醇，表明该酶负责观察到的侧链单加氧酶作用。从 2-和 3-氯甲苯形成两种甲基和氯取代的 1,2-二羟基环己二烯作为次要产物，而从 4-氯甲苯形成唯一的氯和甲基取代的环己二烯。恶臭假单胞菌 F1 的甲苯双加氧酶和伯克霍尔德氏菌 PS12 的氯苯双加氧酶是第一个被描述的能够有效催化 2-氯甲苯氧化的酶。
