嗜麦芽窄食单胞菌J12对芘的降解特性

Pyrene Degradation by Stenotrophomonas maltophilia J12 and Its Degradation Characteristics

从前期实验中得到1株对芘具有降解能力的嗜麦芽窄食单胞菌,将其命名为J12。采用摇床振荡培养的方法,研究了不同实验条件(降解体系芘初始浓度、初始pH、投菌量)对J12降解芘的影响。结果表明:最佳降解条件为芘初始浓度20mg/L、投菌量2g/L、pH为7.0左右。在最佳降解条件下,研究了金属离子Fe3+、Mn2+、Mg2+对J12降解芘的影响,结果表明一定浓度Fe3+、Mn2+的投加对J12降解芘具有促进作用,而Mg2+则表现为轻微的抑制作用。向反应体系中添加鼠李糖脂,结果表明鼠李糖脂的添加对J12降解芘有一定的促进作用,其中在反应的后期促进作用较明显。对J12胞外酶和胞内酶粗酶液进行考察,结果表明在J12降解芘过程中起主要作用的为胞内酶,J12对芘的降解酶主要分布在胞内。

A pyrene degrading bacteria named Stenotrophomonas maltophilia J12 was obtained from previous experiment. Effects of initial concentration of pyrene, inoculation, pH, metal ions and rhamnolipid on pyrene degradation by J12 were investigated in mineral salt medium system. Experimental results showed that the optimal environmental conditions were initial pyrene concentration 20mg/L, inoculation 2g/L and pH 7.0. Fe^3＋ and Mn^2＋ ions in certain concentration could accelerate the degradation of J12, while Mg^2＋ showed a depressed effect on removing reaction of the strain. Rhamnolipid could increase the degradation efficiency of pyrene by J12, especially in the later period of reaction time. Pyrene degradation by extracellular enzyme and intracellular enzyme of J12 was also studied and results indicated that intracellular enzyme played a major role in pyrene degradation.