Department of Biology, College of Science, Shantou University, Shantou, 515063, Guangdong Province, People's Republic of China.
Curr Microbiol. 2022 May 20;79(7):200. doi: 10.1007/s00284-022-02872-y.
1,2,5,6,9,10-Hexabromocyclododecanes (HBCDs) are brominated flame retardants causing serious environmental pollution. HBCDs in the environment could be transformed to various products. Identification of transformation products has been performed using various mass-spectrometric techniques. However, bacterial transformation of HBCDs yielding low-level products was not well studied. In this paper, a Rhodococcus strain stu-38 which could stereoselectively transform HBCDs in mineral salt medium, seawater, and growth medium was isolated. Seven potential biotransformation products of HBCDs were identified by using GC-MS. These products, including brominated alkenes, dibromocyclododecadiene and bromocyclododecatriene; brominated alkenols, bromocyclododecadienol and bromocyclododecatrienol; fully debrominated compounds, cyclododecadiendiol, 1,2-epoxy-5,9-cyclododecadiene, and cyclododecadienol, were presented in rather low level which could lead to false negative results. The low-level transformation products should not be ignored because their toxicity was less assessment. This research highlighted identification of the low-level transformation products to reveal the complicated stereoselective biotransformation of HBCDs.
1,2,5,6,9,10-六溴环十二烷（HBCDs）是一种溴系阻燃剂，会造成严重的环境污染。环境中的 HBCDs 可能会转化为各种产物。使用各种质谱技术对转化产物进行了鉴定。然而，细菌对 HBCDs 产生低水平产物的转化尚未得到很好的研究。本文从矿盐培养基、海水和生长培养基中分离出一株能够立体选择性转化 HBCDs 的红球菌菌株 stu-38。使用 GC-MS 鉴定了 HBCDs 的 7 种潜在生物转化产物。这些产物包括溴代烯烃、二溴环十二二烯和溴环十二三烯；溴代烯醇、溴环十二二烯醇和溴环十二三烯醇；完全脱溴化合物，环十二二烯二醇、1,2-环氧-5,9-环十二二烯和环十二二烯醇，其含量较低，可能导致假阴性结果。这些低水平的转化产物不应被忽视，因为它们的毒性尚未得到充分评估。本研究强调了低水平转化产物的鉴定，以揭示 HBCDs 复杂的立体选择性生物转化。
