一株副球菌对邻苯二甲酸酯的降解特性研究

摘要

从受污染的土壤中筛选出1株能同时以邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二(2-乙基)己酯(DEHP)3种邻苯二甲酸酯(PAEs)的混合物作为碳源和能源的菌株MJ3,采用生理生化特性分析和16S rRNA基因序列分析对其进行鉴定;研究了菌株对邻苯二甲酸酯的降解特性,初步探讨了菌株对邻苯二甲酸酯的降解机理.结果表明,菌株MJ3可初步鉴定为副球菌属.菌株最适生长条件为温度30℃,pH值为7.0,在最适条件下,菌株在3 d内即可将质量浓度为780 mg/L(DMP,DBP,DEHP质量浓度各为260 mg/L)的邻苯二甲酸酯降解87%以上.菌株能够在以PAEs的降解中间产物邻苯二甲酸(PA)为唯一碳源的培养液中生长,且对TOC的去除率与邻苯二甲酸酯的去除基本一致,达83%以上,表明MJ3菌株可通过PA途径实现对PAEs的完全矿化.%A bacterial strain MJ3, which could simultaneously utilize three kinds of phthalates (PAEs) DMP, DBP and DEHP as the sole source of carbon and energy, was isolated from contaminated soil. The strain MJ3 was identified according to physiological and biochemical characteristics and 16S rRNA sequences analysis, and biodegradation characteristics of phthalates by strain MJ3 were tested. The results showed that strain MJ3 was identified as Paracoccus sp. The optimum pH and temperature forgrowth of strain MJ3 were 7.0 and 30 ℃, respectively. Under the optimal condition, degradation rate of phthalates with initial concentration of 780 mg/L-1 (containing 260 mg/L of DMP, DBP and DEHP, respectively) was up to 87%within 3 days. Strain MJ3 could grow well with phthalic acid (PA) as sole carbon source, and removal rate of TOC by strain MJ3 could reach more than 83%, according with removal of PAEs basically. It is indicated that phthalates could be completely mineralized by strain MJ3 through PA route.