邻苯二甲酸二(2-乙基己基)酯降解菌群的筛选及特性研究

Isolation of a Bacterial Consortium Degrading Di- (2-Ethylhexyl) Phthalate and Its Biodegradation Characteristics

为了获得高效降解邻苯二甲酸二(2-乙基己基)酯(DEHP)的微生物资源,研究采用富集驯化法从土壤中分离获得1个高效降解DEHP的HM6菌群,并对其群落组成和降解特性进行了研究。结果表明:HM6菌群中最主要的科是Nocardiaceae(64.87%)、Alcaligenaceae(7.91%)、Comamonadaceae(5.34%)、Chitinophagaceae(4.53%),最主要的属为Rhodococcus(57.5%)、unclassified_f_Alcaligencaceae(7.90%)、Gordonia(6.23%)、Hydrogenophaga(3.43%);在含600 mg/L DEHP的培养基中培养3 d后,HM6菌群对培养基中DEHP的降解率可达93.9%;该菌群可在较宽温度、p H值范围内高效降解DEHP,最适降解温度为30或35℃,最适p H值为6.0~8.0,当初始DEHP浓度≤1 000 mg/L时,菌群对DEHP的降解率均大于86%。该研究还考察了HM6菌群在DEHP污染土壤(200 mg/kg)中的应用效果,结果显示21 d试验周期结束时,接种HM6菌群的试验组,DEHP的降解率达70.6%,而对照组的DEHP降解率仅为28.5%。这表明HM6菌群的添加显著提高了污染土壤中DEHP的降解率,其在DEHP污染土壤的生物修复方面具有较高的潜在应用价值。

By the enrichment and domestication approaches,an effective bacterial consortium HM6 for DEHP-degrading was screened from the soil.Analyses on the colony composition and biodegradation characteristics of HM6 were performed.The results showed that in HM6 the predominant families were Nocardiaceae(64.87%),Alcaligenaceae(7.91%),Comamonadaceae(5.34%),and Chitinophagaceae(4.53%).The predominant genera were Rhodococcus(57.5%),unclassified_f_Alcaligencaceae(7.90%),Gordonia(6.23%),and Hydrogenophaga(3.43%).On the 3rd day of culture on medium containing 600 mg/L DEHP,biodegradation rate of HM6 for DEHP was 93.9%.It could efficiently degrade DEHP in a wide range of temperatures and pH values.The optimal temperature and pH for DEHP biodegradation was 30℃or 35℃,and 6.0-8.0,respectively.When the initial concentrations of DEHP were≤1000 mg/L,its degradation rates were all above 86%.This study also investigated the application effect of HM6 in DEHP-contaminated soil(200 mg/kg).The results showed that at the end of the 21-day test period,the degradation rate of DEHP in the test group inoculated with HM6 reached 70.6%,while in the control group was only 28.5%.These results indicate that HM6 can significantly increase the degradation rate of DEHP in contaminated soil,and has great potential in bioremediation of DEHP-contaminated soil.