木糖氧化无色杆菌反硝化亚种细菌的分离鉴定及其菲降解特性研究

利用选择性富集培养及升华法,从石油污染的土壤中分离到2株菲降解细菌,它们在以菲为唯一碳源的培养基上生长良好。应用BIOLOG细菌鉴定系统和分子生物学方法对两株细菌进行鉴定,两株菌分别为坚强芽孢杆菌(Bacillus.firmus)和木糖氧化无色杆菌反硝化亚种(Achromobacter.xylosoxidanssub.sp.denitrificans),两株菌均具有邻苯二酚氧化酶活性。两株细菌在液体培养条件下都表现较强降解菲的能力,液体培养60.h约90%的加入菲被降解。通过测定液体培养基中菲浓度和菌体密度变化发现,菌株降解菲的量与其生长密度相关;随着菌体浓度(吸光度)的增加,代谢底物菲的浓度明显降低,两株菌混合使用能够大幅度提高降解菲的能力。

Isolation of Achromobacter xylosoxidans subsp. denitrificans and it's degradation of phenanthrene

Isolation of polycyclic aromatic hydrocarbon-degrading bacteria was conducted in plate medium using selective enrichment culture.Two isolates of FC31 and FC32 were obtained by the means of sublimation from petroleum-contaminated soil.Both strains grew well on sole carbon of phenanthrene and degraded it efficiently.FC31 was identified as Bacillus firmus and FC32 as Achromobacter xylosoxidans subsp.denitrificans based on analysis of 16S rDNA sequence and Biolog-GN profile.Both strains were of catechol dioxygenase activity and higher phenanthrene-degrading capacities in the broth assay with about 90% of phenanthrene added being degraded during 60 hours incubation.The quantity of phenanthrene degradation was correlated with the OD value.The results indicated that the ability of phenanthrene-degrading was strongly increased when they were used as a mixture.