石油污染土壤中苯酚降解菌ad049的鉴定及降解特性  

Identification and characteristics of phenol degrading bacteria ad049 screened from oil contaminated soil

作　　者：胡婷[1] 谷洁[1,2] 甄丽莎[1,3] 杨玖[1] 史龙翔[1] 王小娟[1] 高华[1,2] 

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100 [2]陕西省循环农业工程技术研究中心,杨凌712100 [3]陕西省微生物研究所,西安710043

出　　处：《生态学报》2014年第5期1140-1148,共9页Acta Ecologica Sinica

基　　金：国家自然科学基金(4087119;41171203);农业部"948"项目(2010-Z20);陕西省科学院青年人才项目(2012K-34)

摘　　要：以苯酚为唯一碳源,采用富集培养方法,从陕北靖边油田污染土壤中分离获得1株苯酚高效降解菌(ad049),对菌株进行形态观察、生理生化检验及16S rDNA序列分析,确定该菌株为红球菌(Rhodococcus)。采用摇瓶振荡培养方法,研究了接种量、pH值、温度和底物浓度对ad049生长量和苯酚降解率的影响,同时对该菌株脱氢酶和邻苯二酚双加氧酶活性进行了测定。结果表明,ad049具有较强的苯酚降解能力;在苯酚浓度1000 mg/L,温度35℃,pH值8,接种量5%的培养条件下,反应24 h后,苯酚降解率达99%以上,且整个降解过程符合零级动力学方程,速率常数k_0=41.51,相关系数R^2=0.96。通过邻苯二酚双加氧酶活性的测定,推测出该菌株降解苯酚的途径可能是以邻苯二酚1,2双加氧酶为主要途径进行邻位开环,辅以邻苯二酚2,3双加氧酶进行间位开环。A bacterium strain, which prove to be highly effective in phenol degrading, was isolated from soil contaminated with oil in Jingbian oilfield of Northern Shaanxi by using enrichment culture method with phenol as a sole carbon source. The bacterium was named ad049 and identified as Rhodococcus on the basis of the morphological characterizations, physiological and biochemical identification, and alignment analysis of the 16S rDNA sequence. Effects of inoculation quantity of ad049, pH, temperature, and concentration of phenol as a substrate on bacterial growth and the efficiency of ad049 on phenol degradation were also investigated by shaker culture method, and dehydrogenase and catechol dioxygenase were determined as well. Results showed that the ad049 had a strong biodegradation capability for phenol. It degraded 99% of the phenol in a concentration of 1000 mg/L in 24 hours under the incubating condition of 30 ℃, pH 8, and 5% of ad049 inoculation. The degradation process could be described with zero order kinetics equation with the k0 and R2 values of 41.51and 0.96, respectively. The degradation of phenol by ad049 might be achieved largely by 1,2-dioxygenase for ortho ring opening of benzene, and partly by catechol 2,3-dioxygenase for meta-cleavage.

关 键 词：石油污染土壤 苯酚 生物降解 红球菌 

分 类 号：X53[环境科学与工程—环境工程]