Spain J C, Nishino S F
Appl Environ Microbiol. 1987 May;53(5):1010-9. doi: 10.1128/aem.53.5.1010-1019.1987.
A Pseudomonas species able to degrade p-dichlorobenzene as the sole source of carbon and energy was isolated by selective enrichment from activated sludge. The organism also grew well on chlorobenzene and benzene. Washed cells released chloride in stoichiometric amounts from o-, m-, and p-dichlorobenzene, 2,5-dichlorophenol, 4-chlorophenol, 3-chlorocatechol, 4-chlorocatechol, and 3,6-dichlorocatechol. Initial steps in the pathway for p-dichlorobenzene degradation were determined by isolation of metabolites, simultaneous adaptation studies, and assay of enzymes in cell extracts. Results indicate that p-dichlorobenzene was initially converted by a dioxygenase to 3,6-dichloro-cis-1,2-dihydroxycyclohexa-3,5-diene, which was converted to 3,6-dichlorocatechol by an NAD+-dependent dehydrogenase. Ring cleavage of 3,6-dichlorocatechol was by a 1,2-oxygenase to form 2,5-dichloro-cis, cis-muconate. Enzymes for degradation of haloaromatic compounds were induced in cells grown on chlorobenzene or p-dichlorobenzene, but not in cells grown on benzene, succinate, or yeast extract. Enzymes of the ortho pathway induced in cells grown on benzene did not attack chlorobenzenes or chlorocatechols.
通过从活性污泥中进行选择性富集，分离出了一种能够将对二氯苯作为唯一碳源和能源进行降解的假单胞菌属细菌。该微生物在氯苯和苯上也生长良好。洗涤后的细胞从邻二氯苯、间二氯苯、对二氯苯、2,5 -二氯苯酚、4 -氯苯酚、3 -氯儿茶酚、4 -氯儿茶酚和3,6 -二氯儿茶酚中以化学计量的量释放出氯离子。通过代谢产物的分离、同步适应性研究以及细胞提取物中酶的测定，确定了对二氯苯降解途径的初始步骤。结果表明，对二氯苯最初由双加氧酶转化为3,6 -二氯 -顺式 -1,2 -二羟基环己 -3,5 -二烯，后者通过一种依赖于NAD⁺的脱氢酶转化为3,6 -二氯儿茶酚。3,6 -二氯儿茶酚的环裂解是由一种1,2 -加氧酶进行的，形成2,5 -二氯 -顺式，顺式 -粘康酸。在以氯苯或对二氯苯生长的细胞中诱导产生了降解卤代芳烃化合物的酶，但在以苯、琥珀酸盐或酵母提取物生长的细胞中则没有。在以苯生长的细胞中诱导产生的邻位途径的酶不会攻击氯苯或氯儿茶酚。
