三苯基锡的微生物降解及其对降解菌的影响

为了探明三苯基锡(TPhT)微生物降解途径,分析TPhT生物降解机制,及降解过程TPhT对降解菌的毒性影响,采用Biolog法研究了克雷伯氏菌处理不同浓度TPhT后菌体利用碳源能力的改变,并利用GC-MS和X射线光电子能谱检测了TPhT的降解产物.处理2 h后,1 mg.L-1TPhT对降解菌利用碳源的促进作用最强.原子力显微镜观察发现,降解TPhT后部分菌体内含物流失,细胞凋亡,但大部分菌体保持完整形态,对照菌体表面出现细小褶皱.胞内酶在120 h内对3 mg.L-1TPhT的降解率即可达66.0%,效果明显优于菌体细胞.综合GC-MS和XPS分析结果发现,TPhT降解过程会产生二苯基锡(DPhT)和一苯基锡(MPhT),并最终形成无机的Sn4+.

Biodegradation of Triphenyltin and Its Effect on Klebsiella pneumoniae

To investigate the pathway and mechanism of triphenyltin (TPhT) biodegradation by Klebsiella pneumoniae, and the effects of TPhT on cells during the degradation process, the alteration of carbon utilization ability of the strain after dealing with different concentrations of TPhT was studied by the Biolog method, and the degradation pathway of TPhT was explored by GC-MS and X-ray photoelectron spectroscopy (XPS). After degradation for 2 h, the nutrient utilization capacity of K. pneumoniae was significantly improved by 1 mg ·L^-1 TPhT. Atomic force microscope observation found that exposure to TPhT changed the cellular morphology, inducing the apoptosis of some cells, but most of the cells still maintained intact and had smooth cell wall. The efficiencies of TPhT removal by intracellular enzyme were up to 66.0% within 120 h, which demonstrated that endoenzyme was more effective than the intact cells. The results of GC-MS and XPS revealed that during the biodegradation process, TPhT was transformed to diphenyltin, monophenyltin and finally inorganic tin.