低温邻苯二甲酸二甲酯降解菌STX-2和STX-5的分离、鉴定及降解特性

Isolation,identification and degradation characteristics of dimethyl phthalate degradation strains STX-2 and STX-5 at low temperature

在高海拔、低气温地区分离得到两株以邻苯二甲酸二甲酯(DMP)为碳源的菌株STX-2和STX-5。经鉴定,STX-2和STX-5分别为假单胞菌属(Pseudomonas)和红球菌属(Rhodococcus)菌株。在单菌试验的基础上,对混菌降解DMP的条件进行了优化。结果表明,混菌在温度为15℃、初始pH为8、140r/min振荡培养72h的条件下,对1 000mg/L的DMP降解效果最好,4种表面活性剂并不能显著提高混菌降解DMP的效果。动力学试验表明,随着DMP初始浓度的增加,降解速度常数降低,半衰期变长。混菌对短链邻苯二甲酸酯(PAEs)降解效果较好,而对长链PAEs降解效果较差。

Two strains （STX-2 and STX-5） capable of utilizing dimethyl phthalate （DMP） as carbon source were isolated from high altitude area with low temperature. STX-2 and STX-5 were identified as Pseudomonas and Rhodococcus,respectively. Based on single strain test,DMP degradation conditions were optimized for mixed strains. Results showed that the best degradation conditions for 1 000 mg/L DMP were temperature of 15 ℃ ,initial pH of 8, 140 r/min of 72 h. Four surfactants were inefficient to improve DMP degradation. Kinetic experiment revealed that as DMP initial concentration raised, degradation kinetic constants declined and half-time elongated. Mixed strains were easy to degradate short-chain phthalic acid esters （PAEs）,but hard to degradate long-chain PAEs.