1株α-蒎烯降解菌的分离鉴定及降解特性研究

从处理废气的生物滤塔内筛选到1株能高效降解α-蒎烯的菌株PT.通过菌落形态、生理生化特征、16SrRNA基因序列相似性分析及Biolog鉴定等方法,确定该菌株属于荧光假单胞菌(Pseudomonas fluorescens).菌株PT最佳生长条件为: NaCl浓度0.00%、pH7.13、温度25.5℃,降解速率达到最大值5.22mg/(L×h).降解过程符合Haldane’s抑制生长动力学模型,最大比降解速率为0.0364h-1.菌株PT能不同程度地降解一些分子结构较为简单或与α-蒎烯结构相似的工业有机污染物.代谢产物分析表明,菌株PT在降解α-蒎烯的过程中产生柠檬油精、紫苏酸等结构较为简单的物质,它们最终被完全矿化为CO2或合成细胞自身组成物质.碳平衡分析表明,底物有机碳含量完全矿化和转化为细胞生物量的比例分别为64.83%和30.37%.

Isolation and identification of an alpha-pinene-degrading bacterium and its degradation characteristics

An aerobic bacterium (strain PT) capable of degrading α-pinene was isolated from the biofilm of a biotrickling filter. Based on its morphology, physiological-biochemical characteristics, 16S rRNA gene sequence analysis and Biolog analysis, the strain PT was identified as Pseudomonas fluorescens. The results of response surface methodology (RSM) indicated that the initial conditions of NaCl concentration 0.00%, pH7.31 and temperature 25.5°C were optimal for its growth with the maximum biodegradation rate. Haldane’s kinetics model could be fit to the kinetics date well and the maximum specific degradation rate was 0.0364h-1. The strain PT could biodegrade several industrial contaminants which were characterized with simple or similar structures to that of α-pinene. GC/MS analysis showed that α-pinene was converted to some simple organic compounds (limonene, perillic acid etc.) by the strain PT, which was finally mineralized to CO2, H2O and synthesized to cell biomass. Analysis of carbon balance indicated that the rates for the mineralization and the biomass synthesis were about 64.83% and 30.37%, respectively.