Studies on hydrogenase activity and chlorobenzene respiration in Dehalococcoides sp strain CBDB1
Studies on hydrogenase activity and chlorobenzene respiration in Dehalococcoides sp strain CBDB1
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DOI：
10.1007/s00203-004-0734-9
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发表时间：
2004-12-01
影响因子：
2.8
通讯作者：
Adrian, L
中科院分区：
文献类型：
--
作者：
Jayachandran, G;Görisch, H;Adrian, L
研究了利用氯苯的厌氧菌 Dehalococcoides sp 的氢氧化和电子传递。菌株CBDB1。 Cu2+ 和 Hg2+ 离子不可逆地抑制完整细胞中的氢化酶活性，而 Ni2+ 离子则可逆地抑制。当细胞暴露在空气中时，约 80% 的初始氢化酶活性在 30 秒内失活。相反，当用氧化还原指示剂缺氧地建立氧化还原电位时，氢化酶在+10 mV的氧化还原电位下具有活性。紫罗碱染料既充当氢化酶的电子受体又充当脱卤酶的电子供体。甲基萘醌类似物2,3-二甲基1,4-萘醌既不充当氢化酶的电子受体，也不充当脱卤酶的电子供体。此外，甲基萘醌拮抗剂2-n-庚基-4-羟基喹啉-N-氧化物对细胞悬浮液或以氢为电子供体的分离膜催化的脱氯没有影响，进一步支持了甲基萘醌不参与电子传递的观点。离子载体四氯水杨酰苯胺和羰基氰化物间氯苯腙不抑制细胞悬浮液的脱氯作用，表明菌株CBDB1不需要反向电子传递。 ATP合酶抑制剂N,N'-二环己基碳二亚胺抑制细胞悬液的脱氯反应；然而，后一种影响通过添加四氯水杨酰苯胺而部分缓解。 1,2,3,4-四氯苯强烈抑制以氢为电子供体的细胞悬浮液对其他氯苯的脱氯作用，但它不干扰氢化酶或脱卤酶活性。
Hydrogen oxidation and electron transport were studied in the chlorobenzene-utilizing anaerobe Dehalococcoides sp. strain CBDB1. While Cu2+ and Hg2+ ions irreversibly inhibited hydrogenase activity in intact cells, Ni2+ ions inhibited reversibly. About 80% of the initial hydrogenase activity was inactivated within 30 s when the cells were exposed to air. In contrast, hydrogenase was active at a redox potential of + 10 mV when this redox potential was established anoxically with a redox indicator. Viologen dyes served both as electron acceptor for hydrogenase and electron donor for the dehalogenase. A menaquinone analogue, 2,3-dimethyl 1,4-naphthoquinone, served neither as electron acceptor for the hydrogenase nor as electron donor for the dehalogenase. In addition, the menaquinone antagonist 2-n-heptyl-4-hydroxyquinoline-N- oxide had no effect on dechlorination catalyzed by cell suspensions or isolated membranes with hydrogen as electron donor, lending further support to the notion that menaquinone is not involved in electron transport. The ionophores tetrachlorosalicylanilide and carbonylcyanide m-chlorophenylhydrazone did not inhibit dechlorination by cell suspensions, indicating that strain CBDB1 does not require reverse electron transport. The ATP-synthase inhibitor N,N'-dicyclohexylcarbodiimide inhibited the dechlorination reaction with cell suspensions; however, the latter effect was partially relieved by the addition of tetrachlorosalicylanilide. 1,2,3,4-Tetrachlorobenzene strongly inhibited dechlorination of other chlorobenzenes by cell suspensions with hydrogen as electron donor, but it did not interfere with either hydrogenase or dehalogenase activity.