Applied Biochemistry, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355 Berlin, Germany.
Environ Sci Technol. 2012 Aug 21;46(16):8960-8. doi: 10.1021/es3003519. Epub 2012 Aug 3.
Brominated aromatics are used in many different applications but occur also naturally. Here, we demonstrate organohalide respiration and growth of Dehalococcoides mccartyi strain CBDB1 with 1,2,4-tribromobenzene, all three dibrominated benzene congeners and monobromobenzene. All bromobenzenes were fully dehalogenated to benzene. Growth yields were between 1.8 × 10(14) and 2.8 × 10(14) cells per mol of bromide released. Furthermore, a newly designed high-throughput methyl viologen-based photometric microtiter plate assay was established to determine the activity of the reductive dehalogenases in resting cell assays of strain CBDB1 with brominated aromatics as electron acceptors. Activities of 2.8-13.2 nkat per mg total cell protein (0.16-0.8 units per mg total cell protein) were calculated after cultivation of strain CBDB1 on 1,2,4-tribromobenzene. Mass spectrometric analyses and activity assays with whole cell extracts of strain CBDB1 gave strong evidence that four to six reductive dehalogenases were involved in the dehalogenation of all tested brominated benzenes, including the reductive dehalogenases CbdbA80 and CbrA.
溴代芳烃被广泛应用于许多不同的领域，同时也存在于自然界中。在这里，我们展示了 Dehalococcoides mccartyi 菌株 CBDB1 对 1,2,4-三溴苯、三种二溴苯同系物和一溴苯的有机卤化物呼吸作用和生长情况。所有的溴苯都被完全脱卤化成苯。溴化物释放的摩尔数与细胞生长的产率比值为 1.8×10(14)至 2.8×10(14)。此外，我们还建立了一种新的高通量基于甲紫精的分光光度微板测定法，用于测定以溴代芳烃为电子受体时 CBDB1 菌株的还原脱卤酶在静止细胞测定中的活性。在以 1,2,4-三溴苯为碳源培养 CBDB1 菌株后，计算出的还原脱卤酶活性为 2.8-13.2 nkat/mg 总细胞蛋白（0.16-0.8 单位/mg 总细胞蛋白）。对 CBDB1 菌株的全细胞提取物进行质谱分析和活性测定，有力地证明了四种到六种还原脱卤酶参与了所有测试的溴代苯的脱卤反应，包括 CbdbA80 和 CbrA 还原脱卤酶。
