AEROBIC DEGRADATION OF POLYCHLORINATED BIPHENYLS

多氯联苯(多氯联苯)被广泛使用， 现在被认为是最具问题的污染物之一。最多的 多氯联苯的生物修复是一种很有前途的方法 厌氧-好氧工艺。厌氧降解导致还原 高氯化多氯联苯的脱氯和少量积累 氯化的同系物。8个同系物，包括2-，4-，2，4-，2，6-， 2-2-、2-4-、2，4-2-和2，4-4-氯联苯(CB)由70 至85%的Aroclor 1242厌氧脱氯产物。 虽然已经对许多好氧细菌进行了筛选，以确定其光谱 它们可以降解的多氯联苯，人们对降解知之甚少， 在厌氧过程中积累的同系物形成的最终产物 脱氯过程。为此选择了四个细菌菌株 基于其卓越的多氯联苯降解能力进行的调查。质量 用光谱分析方法对其进行特异性分析。 多氯联苯的攻击和最终产物由需氧细菌形成。基座 关于质谱学、紫外谱学和高效液相数据菌株的研究 红球菌属RHA1和伯克霍尔德菌(Burkholderia sp.)LB400总结为 优先攻击邻氯环，而另外两个 菌株(素共生单胞菌VP44和红球菌)。(NY05) 优先氧化了一对位取代环。事实证明， 邻位聚焦菌株对阿罗克罗的降解效率更高 厌氧脱氯产品。众所周知，有氧运动 多氯联苯的降解通常涉及部分降解和结果 在氯苯甲酸酯的生产中。我们还发现了氯苯甲酸盐 作为选定同系物降解的主要产物。然而， 对位聚集菌对2-4和2，4-CB的降解 这些同系物的不完全转化和积累 这些氯联苯的间位裂解产物是死胡同 代谢物。这些化合物是根据质量鉴定出来的。 光谱数据(GC-MS)。

Polychlorinated biphenyls (PCBs) were widely used and are considered now as one of the most problematic pollutants. The most promising approach for bioremediation of PCBs is a combined anaerobic-aerobic process. Anaerobic degradation results in reductive dechlorination of highly chlorinated PCBs and accumulation of less chlorinated congeners. Eight congeners including 2-, 4-, 2,4-, 2,6-, 2-2-, 2-4-, 2,4-2-, and 2,4-4-chlorobiphenyl (CB) comprise from 70 to 85% of anaerobic dechlorination products from Aroclor 1242. Although many aerobic bacteria have been screened for the spectra of PCBs which they can degrade, little is known about degradation and final products formed from congeners that accumulate during anaerobic dechlorination processes. Four bacterial strains were chosen for this investigation based on their superb PCB degradative abilities. Mass spectrometry was employed to analyze the specificity of the primary PCBs attack and the final products formed by aerobic bacteria. Based on mass spectrometry, UV-spectroscopy and HPLC data strains Rhodococcus sp. RHA1 and Burkholderia sp. LB400 were concluded to preferentially attack on ortho-chlorinated rings, while another two strains (Commamonas testosteroni VP44 and Rhodococcus sp. NY05) preferentially oxidized a para-substituted rings. It was shown that the ortho-focused strains showed more efficient degradation of Aroclor anaerobic dechlorination products. It is known that aerobic degradation of PCBs usually involves partial degradation and results in the production of chlorobenzoates. We also found chlorobenzoates as the major products of degradation of selected congeners. However, degradation of 2-4 and 2,4-4-CB by para-focused bacteria resulted in incomplete transformation of these congeners and accumulation of meta-cleavage products of these chlorobiphenyls as a dead end metabolites. These compounds were identified based on mass spectrometric data (GC-MS).