高分子量多环芳烃降解菌LD29的筛选及降解特性研究  

Isolation and Degradation Characteristics of a HMW PAHs-Degrading Strain LD29

作　　者：刘芳[1] 梁金松[1,2] 孙英[3] 郭岩彬[1] 李庆孝 李季[1] 

机构地区：[1]中国农业大学资源与环境学院,北京100193 [2]中国科学院生态环境研究中心环境水质学国家重点实验室,北京100085 [3]中国农业大学理学院,北京100193 [4]美国夏威夷大学生物科学与生物工程系,夏威夷96822

出　　处：《环境科学》2011年第6期1799-1804,共6页Environmental Science

基　　金："十一五"国家科技支撑计划项目(2006BAD10B09);2008粤港关键领域重点突破项目(2009205200031);广东省2008年省部产学研结合项目(2008A090400001);农业部公益性行业科研专项(200803033)

摘　　要：采用硅油-水双液相富集体系,以蒽为富集碳源,从原油污染土壤富集分离多环芳烃降解菌,分离出1株能降解菲、蒽、荧蒽、芘、苯并[a]芘的细菌,经形态特征、生理生化和16S rDNA鉴定为矢野口鞘氨醇菌(Sphingobium yanoikuyae),编号为LD29.采用高效液相色谱(HPLC)对LD29在无机盐培养基中对PAHs的降解特性做了研究.LD29能以唯一碳源与能源方式降解菲、蒽、荧蒽、芘(初浓度均为50 mg/L),4 d的降解率分别为92%、87%、28%、7%,但未能降解苯并[a]芘.蒽能促进LD29对荧蒽/芘的降解,而荧蒽/芘则抑制LD29对蒽的降解.较高初始pH(pH=9)的培养基有利于LD29对混合多环芳烃的降解.外加营养可促进LD29对荧蒽的降解.外加碳源(葡萄糖,200 mg/L)或氮源(蛋白胨,50 mg/L)处理中荧蒽(100 mg/L)6 d的降解率分别为69%、81%,而对照组只有34%.在含有5种多环芳烃(菲、蒽、荧蒽、芘、苯并[a]芘)的无机盐培养基溶液中,LD29在4 d的适应期之后开始快速降解高分子量多环芳烃,6 d芘和荧蒽的降解率(48%、66%)比4 d分别增加40%、56%,并且苯并[a]芘也被降解了17%.LD29具有降解高分子量PAHs的潜力.Two-liquid-phase（silicone oil-water） culture enrichment systems,with anthracene as carbon source,was used to enrichment PAHs-degrading strains from contaminated soil by crude oil.One strain,which can degrade phenanthrene,anthracene,fluoranthene,pyrene and benzo[a]pyrene,was isolated and identified as Sphingobium yanoikuyae based on 16S rDNA sequences,phenotypic characteristics and physio-biochemistry characteristics,and numbered as LD29.Degradation characteristics of LD29 in mineral salts medium（MSM） was measured by HPLC.After 4 days of growing in MSM with single PAH as carbon source,LD29 degraded phenanthrene,anthracene,fluoranthene,pyrene（initial concentration： 50 mg/L） by 92%,87%,28% and 7% respectively,but no benzo[a]pyrene was degraded.Anthracene enhanced the degradation of fluoranthene/pyrene by LD29,whereas fluoranthene/pyrene impeded anthracene degradation by LD29.MSM with high initial pH value（pH=9） favored the degradation of PAHs mixture in MSM by LD29.The degradation activity of LD29 can be improved by additional nutrition.Additional carbon source（glucose,200 mg/L） or nitrogen source（peptone,50 mg/L） accelerated fluoranthene（100 mg/L） degradation in MSM,with degradation rate 69%,81% respectively（CK： 34%） within 6 days.LD29 started to significantly degrade HMW PAHs from the 4th day in MSM with 5 PAHs（phenanthrene,anthracene,fluoranthene,pyrene and benzo[a]pyrene）,and the degradation rate of pyrene and fluoranthene at day 6 were 44% and 58% higher than those of day 4 respectively,and the degradation rate of benzo[a]pyrene also reached to 17% at day 6.LD29 has significant potential for PAHs degradation,including high molecular weight（HMW） PAHs.

关 键 词：高分子量 多环芳烃 生物降解 矢野口鞘氨醇菌 

分 类 号：X172[环境科学与工程—环境科学]