菲高效降解菌的降解特性及其受蒙脱石的影响研究

通过选择性富集培养与纯化,从广州油制气厂附近的污染土壤中分离获得一株能以菲为唯一碳源和能源,快速生长的优势菌株（编号为YZ-1）。16S rDNA序列分析结果表明,YZ-1菌株为琼氏不动杆菌（Acinetobacter junii）。当无机盐培养液中菲初始质量浓度为100mg·L-1时,45h内该菌株对菲的降解率可达到99.5%。YZ-1菌株的最佳生长条件为pH7.4,温度30℃,摇床转速160r·min-1。加入蒙脱石矿物之后,在降解的初期（前16h）表现为促进菲的生物降解作用,但随着时间的延长,菲的降解速率逐渐低于不加蒙脱石体系,并随蒙脱石含量或菲质量浓度的增加,此抑制延缓现象愈加明显。矿物对高浓度的菲具有吸附分散作用,而对低浓度的菲具有吸附保护作用。

Degradation characteristics of a highly efficient phenanthrene-degrading strain and the effects of montmorillonite

A rapidly growing predominant strain（YZ-1）,which utilizes phenanthrene as the sole carbon and energy source,was obtained by selective accumulation and purification from contaminated soil samples collected near Guangzhou Oil Gas Plant.Sequence analysis of 16S rDNA revealed that YZ-1 belongs to Acinetobacter junii.The degradation ratio of PHE by YZ-1 can reach 99.5% in 45 h with an initial PHE concentration of 100 mg.L-1 in an inorganic salt medium.The optimum conditions for the degradation were：pH 7.4,30 ℃,and 160 r·min-1 of shaking flask culture.Introduction of montmorillonite to the medium enhanced the PHE degradation ratio at the initial stage,the first 16 h;thereafter,the degradation of PHE was restrained and the degradation ratio gradually decreased to less than that without montmorillonite present;this phenomenon became even more obvious with the gradual increase of montmorillonite amount and/or PHE concentration.The result reveals that montmorillonite has adsorption-dispersion effect for PHE of high concentration level while adsorption-protection for PHE of low concentration level.