摘要
为丰富石油降解微生物菌种库,筛选更加高效、适应性更强的降解菌株,从西部荒漠地区石油污染土壤中分离石油降解菌,经细菌形态学、生理生化及16S r DNA序列分析进行鉴定,采用紫外分光光度法和气相色谱质谱联用(GC-MS)研究菌株生长及降解特性,利用PCR检测石油烃代谢相关基因.结果显示,分离的3株石油降解菌株KB1、2182和JC3-47在含油培养基中培养3 d后,石油降解率分别为41.02%、32.26%和55.90%,3株菌均属于红球菌属(Rhodococcus spp.),其中KB1与红平红球菌(Rhodococcus erythropolis)、2182与马红球菌(Rhodococcus equi)、JC3-47与庆笙红球菌(Rhodococcus qingshengii)的16S r DNA序列相似性分别均为100%,初步确定3株菌属于红平红球菌、马红球菌和庆笙红球菌.在温度10-50℃,p H 3-9,盐度为0-5.0%条件下菌株能很好生长,KB1和2182的最适生长温度为35℃,JC3-47最适温度为30℃,KB1和2182还可在p H 2和9.0%盐度的极端条件下生长.菌株能以十二烷、十八烷、苯、甲苯、二甲苯和萘为唯一碳源生长,其中KB1和J C3-47还能在含芘的培养基生长.GC-MS分析发现3株菌对中链及长链烷烃都具有较强降解能力,能产生表面活性剂,对十六烷具有一定粘附能力.利用特异性PCR扩增,在3株菌中均检测到烷烃单加氧酶基因、芳香烃双加氧酶基因和邻苯二酚双加氧酶基因,在KB1和2182中还检测出联苯双加氧酶基因.本研究表明,3株红球菌具有较强石油降解能力,适应性强,可用于高盐、低温等极端环境石油污染土壤的生物修复.
Oil pollution is one of the major factors causing environmental deterioration.Bioremediation of oil contaminated environments by microorganisms attracts much research attention.This study aimed to screen efficient oil-degrading bacteria from oil contaminated soil and analyze their characteristics and catabolic genes.Oil-degrading bacteria were screened from oil contaminated soil in minimal medium containing crude oil and identified by morphological,physiological and biochemical characteristics and 16 S rDNA sequence analysis.Their growth and degradation characteristics were studied with ultraviolet spectroscopy and GC-MS analysis.The surfactant production was studied by adopting culture method.The major oil-degrading related genes were detected by the PCR amplification.As a result,three oil-degrading bacteria strains named KB1,2182 and JC3-47 were isolated from the oil contaminated soil samples.The strains could use crude oil as the sole carbon source to degrade oil with a degrading rate of 41.02%,32.26%and 55.90%,respectively,when cultured in minimal medium containing crude oil for 3 days.The bacteria were identified to belong to genus Rhodococcus.With 100%similarity of 16 S rDNA sequences of the three strains with known ones of Rhodococcus,KB1 was preliminarily identified as Rhodococcus erythropolis,2182 as Rhodococcus equi,and JC3-47 as Rhodococcus qingshengii.They grew well at 10-50 ℃,with the initial pH of 3-9 and the NaCl concentration of 0-5%.The optimal temperature for bacterial growth was 35 ℃,35 ℃ and 30 ℃respectively.KB1 and 2182 could grow at pH 2 and 9.0%of NaCl.The bacteria grew well in broth containing different organic substrates as sole carbon source,such as n-dodecane,n-octadecane,benzene,methylbenzene,xylene and naphthaline.KB1 and JC3-47 could grow well in broth containing pyrene.GC-MS analysis revealed that the bacteria could effectively degrade medium- and long-chain alkane components in crude oil.The bacteria produced biosurfactants and decreased the surface tension of the culture b
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2015年第5期805-812,共8页
Chinese Journal of Applied and Environmental Biology
基金
国家自然科学基金项目(31272694)资助~~
