【摘要】 从石油污染土壤中分离到两株可以菲为唯一碳源的细菌菌株,经形态和生理生化特性分析,脂肪酸含量分析和16S rDNA序列同源性鉴定, 两菌均属鞘氨醇单胞菌属(Sphingomonas),菌株ZX4为少动鞘氨醇单胞菌(Sphingomonas paucimobilis),而菌株EVA17与该属内已知菌的序列同源性在93%~98%之间,推测可能为一新种.两菌株在不同碳源培养基上的生长曲线表明菲对细菌生长有明显的延滞作用.菌株EVA17全细胞蛋白质电泳图谱揭示该细菌在菲诱导下可出现诱导性蛋白,推测可能为一些解毒酶或降解酶.菲降解细菌在以结晶态菲为碳源时生长速率明显低于以粉末态菲为碳源时的生长速率,表明细菌与菲间的接触面积是限制其利用菲的一个重要因素.分离菌株谷胱甘肽S-转移酶(GST酶)具有可与1-氯-2,4-二硝基苯(CDNB)结合的活性.添加表面活性剂吐温-80可促进细菌对菲的利用.更多还原

【Abstract】 Two strains which could use phenanthrene as sole carbon source were isolated from oil-contaminated soil. Both strains were belonged to Sphingomonas based on morphological and physio-biochemical characteristics, fatty acid content analysis and homology identification of 16S rDNA sequence, in which the strain ZX4 was identified as Sphingomonas paucimobilis, while the strain EVA17 was guessed as a new species due to 93%~98% homology with all known species in the genus. The curves of growth on different carbon sources cultivation showed that phenanthrene could delay markedly the growth of the bacteria. Whole cell protein SDS-PAGE map of strain EVA17 revealed that the induced protein may be detoxication enzyme or degrading enzyme which emerged in strain EVA17. The growth rate of the bacteria using crystal phenanthrene was lower markedly than using powered phenanthrene, indicating that their contacting area was an important limit factor for utilizing phenanthrene. The determination of GST (glutathione S-transferase) indicated that the GSTs isolated had the activity of conjugating with CDNB (1-chloro-2, 4-dinitrobenzene). Addition of surface activator tween 80 could improve the utilization of phenanthrene by the bacteria.更多还原