芘降解菌DY-1的条件优化及降解动力学特性分析

Characteristic analysis of optimization and degradation kinetics of pyrene-degrading strains DY-1(Pseudomonas sp.)

选用已筛选出以芘为唯一碳源的假单胞菌DY-1(Pseudomonas sp.)作为芘降解菌,采用摇瓶振荡培养方法,研究了不同环境条件对菌DY-1降解芘效率的影响以及降解动力学特性。结果表明,在含芘50 mg/L的条件下培养9 d,降解率达83.2%。最适宜温度为30℃,pH值为7.5,摇床转速为120 r/min,接种量为1.5 mL;在不同培养条件下芘的降解符合一级动力学模型;低浓度Zn2+,Cd2+,Cr6+的存在对芘降解效果影响较小,Cu2+,Pb2+对芘的降解有较强的毒性;加入低浓度有机物质,蔗糖可提高DY-1芘的降解;低浓度萘或蒽的存在可促进芘的降解。

A selection of a pyrene degradation strains was bacteria DY-1（Pseudomonas sp.） which had cultured and could use pyrene as the sole carbon source.Used shaking cultivation method,the dynamic properties and the effects of different conditions by DY-1 were investigated.The results showed that,the highest removal rate of pyrene was 83.2% after 9 d,while the initial concentration of pyrene was 50 mg/L.The optimal condition was 30 ℃,pH was 7.5,rotational speed was 120 r/min and inoculation was 1.5 mL.The degradation of pyrene conformed to the first-order reaction dynamic properties under different culture conditions.Low concentration of Zn2＋,Cd2＋,Cr6＋ could partially inhibit the degradation rate of pyrene,and Cu2＋,Pb2＋ were toxic to it.When the low concentration organic compound was added into the system with pyrene,sucrose could enhance the degradation of pyrene.The low concentration naphthaene and Anthracene could enhance the degradation of pyrene.