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2,2’,4,4’-四溴联苯醚(BDE-47)是环境和生物体中普遍检出且生物毒性较大的一种多溴联苯醚同系物.本研究从广东省贵屿镇电子垃圾拆解厂周边采集的农田土壤中分离出一株BDE-47的高效好氧降解菌GYP1,考察了其对BDE-47的降解性能、降解路径及不同的环境因素对菌株降解BDE-47的影响.根据菌株形态特征、16S r DNA基因序列及系统发育树分析,将该菌鉴定为伯克霍尔德菌(Burkholderia cepacia).结果表明,菌株GYP1在好氧条件下能够利用BDE-47为唯一碳源生长,在BDE-47初始质量浓度为1 mg·L~(-1)、温度为30℃、摇床转速为150r·min~(-1)的条件下避光培养4 d,该菌株对BDE-47的降解率可达到82.4%.菌株GYP1在15~35℃和p H=4.0~7.0的环境条件范围内对BDE-47均能保持良好的降解性能,但外加蔗糖、酵母粉、联苯醚等碳源会明显抑制其对BDE-47的降解.在菌株GYP1对BDE-47的降解过程中检测到6-OH-BDE-47、5-OH-BDE-47、4’-OH-BDE-17、2’-OH-BDE-3这4种羟基多溴联苯醚及2,4-二溴苯酚,证明菌株GYP1对BDE-47的好氧降解机理主要是羟基化过程.
2,2 ’, 4,4’-tetrabromodiphenyl ether (BDE-47) is a polybrominated diphenylether homologue that is commonly detected in the environment and organisms and has a high biological toxicity.This study was conducted from Guiyu, An aerobic biodegradation bacterial strain, BDE-47, GYP1, was isolated from farmland collected around the e-waste dismantling plant. The degradability of BDE-47, its degradation pathway and different environmental factors were investigated. The strain was identified as Burkholderia cepacia according to its morphological characteristics, 16S r DNA sequence and phylogenetic tree analysis.The results showed that strain GYP1 could utilize BDE-47 under aerobic conditions As the only carbon source, it was cultured under the conditions of initial BDE-47 concentration of 1 mg · L -1, temperature of 30 ℃ and shaking speed of 150 r · min -1 for 4 days. The degradation rate of BDE-47 strain was 82.4% .The strains GYP1 could maintain good degradability to BDE-47 under the environmental conditions of 15-35 ℃ and p H = 4.0-7.0, The degradation of BDE-47 by carbon source, such as powder and diphenylether, was significantly inhibited.During the degradation of BDE-47 by strain GYP1, 6-OH-BDE-47,5-OH-BDE-47 4’-OH-BDE-17,2’-OH-BDE-3-hydroxy-the four polybrominated diphenyl ethers and 2,4-dibromophenol, GYP1 strain proved to aerobic degradation mechanism is mainly BDE-47 hydroxylation process.