Laboratory of Organic Geochemistry, Tokyo University of Agriculture and Technology, 3-5-8, Saiwaicho, Fuchu, Tokyo 183-8509, Japan.
Aqua Restoration Research Center, Public Works Research Institute, National Research and Development Agency, Kawashima Kasada-machi, Kakamigahara, Gifu 501-6021, Japan; United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
Sci Total Environ. 2022 Feb 1;806(Pt 3):151265. doi: 10.1016/j.scitotenv.2021.151265. Epub 2021 Oct 29.
Polybrominated diphenyl ethers (PBDEs) are known to be broken down by debromination reactions in the natural environment, such as by photolysis, microbial and metabolic processes. Although species-specific debromination of PBDEs by fish has also been reported, it has only rarely been studied from the phylogenetic perspective. The objective of this study is to reveal the factors affecting species-specific debromination through validation between the bioaccumulation of PBDEs in muscle tissue and the ability to debrominate BDE99. As environmental observations, PBDE concentrations in muscle tissues were analyzed in 25 wild fish (Cyprinidae, Gobiidae and others). As in vitro experiments, debromination experiments were conducted using the hepatic microsomes of 21 fish species. Significant amounts of BDE99 were detected in almost none of the Cyprinidae. A relatively higher debromination ability was confirmed in the Cyprinidae in in vitro experiments. The Cyprinidae thus appears to be a family with high debromination ability. BDE99 has been detected in some goby species but not others. This pattern was also seen in in vitro experiments, suggesting that debromination ability is not consistent within the Gobiidae. In further quantitative comparisons, kinetic parameters such as K and v were determined for selected fish species. The common carp (Cyprinus carpio) and the Japanese crucian carp (Carassius cuvieri), both Cyprinidae, showed higher v values, whereas v values among three Gobiidae diverged widely. A comparison of field observations and in vitro experiments, revealed the bioaccumulation ratio of BDE99 to be affected by the BDE99 debromination ability of each fish species. This is the first report on classification of BDE99 accumulation ratio by debromination ability and a phylogenetic species comparison based on kinetic parameters for debromination reactions of PBDEs by fish.
多溴二苯醚（PBDEs）已知会在自然环境中通过脱溴反应分解，如光解、微生物和代谢过程。尽管鱼类对 PBDEs 的种特异性脱溴作用也有报道，但从系统发育的角度研究很少。本研究的目的是通过验证肌肉组织中 PBDEs 的生物积累与脱溴 BDE99 的能力之间的关系，揭示影响种特异性脱溴的因素。作为环境观察，分析了 25 种野生鱼类（鲤科、虾虎鱼科等）肌肉组织中的 PBDE 浓度。作为体外实验，使用 21 种鱼类的肝微粒体进行了脱溴实验。在鲤科鱼类中几乎没有检测到大量的 BDE99。在体外实验中，确认了鲤科鱼类具有较高的脱溴能力。因此，鲤科鱼类似乎是一种具有高脱溴能力的家族。在一些虾虎鱼科鱼类中检测到 BDE99，但在其他鱼类中没有检测到。在体外实验中也观察到了这种模式，这表明脱溴能力在虾虎鱼科鱼类中并不一致。在进一步的定量比较中，为选定的鱼类物种确定了动力学参数，如 K 和 v。鲤科的鲤鱼（Cyprinus carpio）和日本鲫（Carassius cuvieri）显示出较高的 v 值，而三种虾虎鱼科鱼类的 v 值差异很大。将现场观察和体外实验进行比较，揭示了 BDE99 的生物积累比受每种鱼类的 BDE99 脱溴能力的影响。这是第一个根据鱼类对 PBDEs 的脱溴反应的动力学参数对 BDE99 积累比进行分类和系统发育物种比较的报告。
