Adrian L, Szewzyk U, Wecke J, Görisch H
Fachgebiet Technische Biochemie, Technische Universität, Berlin, Germany.
Nature. 2000 Nov 30;408(6812):580-3. doi: 10.1038/35046063.
Chlorobenzenes are toxic, highly persistent and ubiquitously distributed environmental contaminants that accumulate in the food chain. The only known microbial transformation of 1,2,3,5-tetrachlorobenzene (TeCB) and higher chlorinated benzenes is the reductive dechlorination to lower chlorinated benzenes under anaerobic conditions observed with mixed bacterial cultures. The lower chlorinated benzenes can subsequently be mineralized by aerobic bacteria. Here we describe the isolation of the oxygen-sensitive strain CBDB1, a pure culture capable of reductive dechlorination of chlorobenzenes. Strain CBDB1 is a highly specialized bacterium that stoichiometrically dechlorinates 1,2,3-trichlorobenzene (TCB), 1,2,4-TCB, 1,2,3,4-TeCB, 1,2,3,5-TeCB and 1,2,4,5-TeCB to dichlorobenzenes or 1,3,5-TCB. The presence of chlorobenzene as an electron acceptor and hydrogen as an electron donor is essential for growth, and indicates that strain CBDB1 meets its energy needs by a dehalorespiratory process. According to their 16S rRNA gene sequences, strain CBDB1, Dehalococcoides ethenogenes and several uncultivated bacteria form a new bacterial cluster, of which strain CBDB1 is the first, so far, to thrive on a purely synthetic medium.
氯苯是有毒、高度持久且广泛分布的环境污染物，会在食物链中累积。已知的1,2,3,5 - 四氯苯（TeCB）及更高氯代苯的唯一微生物转化途径是在厌氧条件下，通过混合细菌培养物将其还原脱氯为低氯代苯。低氯代苯随后可被好氧细菌矿化。在此，我们描述了对氧敏感的菌株CBDB1的分离，这是一种能够对氯苯进行还原脱氯的纯培养物。菌株CBDB1是一种高度专业化的细菌，它能化学计量地将1,2,3 - 三氯苯（TCB）、1,2,4 - TCB、1,2,3,4 - TeCB、1,2,3,5 - TeCB和1,2,4,5 - TeCB还原脱氯为二氯苯或1,3,5 - TCB。氯苯作为电子受体和氢气作为电子供体的存在对其生长至关重要，这表明菌株CBDB1通过脱卤呼吸过程满足其能量需求。根据它们的16S rRNA基因序列，菌株CBDB1、产乙烯脱卤球菌及几种未培养细菌形成了一个新的细菌簇，其中菌株CBDB1是迄今为止首个能在纯合成培养基上生长的菌株。
