Lambo A J, Patel T R
Applied Microbiology and Biotechnology Laboratory, Department of Biology, Memorial University of Newfoundland, St John's, NL, Canada.
Lett Appl Microbiol. 2007 Apr;44(4):447-53. doi: 10.1111/j.1472-765X.2006.02070.x.
The present work investigates the possibility that temperature could regulate the pattern of transformation of 2,4'-chlorobiphenyl (2,4'-CB) by psychrotolerant Hydrogenophaga sp. IA3-A.
Transformation of 2,4'-chlorobiphenyl to 2- and 4-chlorobenzoic acid (2- and 4-CBA), and meta-cleavage products by cells of strain IA3-A incubated at 10 degrees C, 25 degrees C, 37 degrees C or 45 degrees C were monitored by UV spectrometry, HPLC and GC-MS analyses. Cultures incubated at 10 degrees C, 25 degrees C or 37 degrees C produced low amounts of CBAs and excess levels of meta-cleavage products from 2,4'-CB. Cultures incubated at 45 degrees C transformed most of the degraded 2,4'-CB to CBAs and low level of meta-cleavage product. Culture extracts contained unusual varieties of isomeric hydroxylated metabolic products.
Efficient transformation of 2,4'-CB to CBAs was possible in cultures incubated at 45 degrees C. Evidence for the involvement of multiple pathways in the transformation of 2,4'-CB in strain IA3-A suggests that differential regulation of the pathways at different temperatures was likely responsible for the change in the pattern of transformation of 2,4'-CB in cultures incubated at 45 degrees C.
It may be possible to condition cells to transform chlorinated biphenyls more efficiently without accumulating excess level of toxic intermediates.
本研究探讨温度是否能够调节耐冷嗜氢菌IA3 - A对2,4'-氯联苯（2,4'-CB）的转化模式。
通过紫外光谱法、高效液相色谱法和气相色谱 - 质谱分析法监测菌株IA3 - A的细胞在10℃、25℃、37℃或45℃下培养时，2,4'-氯联苯向2 - 和4 - 氯苯甲酸（2 - 和4 - CBA）以及间位裂解产物的转化情况。在10℃、25℃或37℃下培养的菌液产生少量的氯苯甲酸和过量的2,4'-CB间位裂解产物。在45℃下培养的菌液将大部分降解的2,4'-CB转化为氯苯甲酸，间位裂解产物水平较低。培养物提取物含有不同寻常的多种异构羟基化代谢产物。
在45℃下培养的菌液中，2,4'-CB能够高效转化为氯苯甲酸。菌株IA3 - A中2,4'-CB转化涉及多种途径的证据表明，不同温度下这些途径的差异调节可能是导致45℃下培养的菌液中2,4'-CB转化模式变化的原因。
有可能使细胞更有效地转化氯代联苯，而不会积累过量的有毒中间体。
