哌嗪高效降解菌PIPA-6的分离筛选及降解特性

从制药厂周边土壤分离获得一株哌嗪高效降解菌株PIPA-6，其能在以哌嗪为唯一能量来源的无机培养基中生长，30h对100mg/L的哌嗪降解率达100%.形态学观察、生理生化鉴定和16S rDNA基因序列同源性分析表明，菌株为嗜烟碱类节杆菌（Paenarthrobacter nicotinovorans）.菌株PIPA-6具有广泛的温度（10~40℃）和pH（5~10）适应范围、优良的钠盐耐受性（50g/L）和极强的哌嗪抗性（300mg/L），其最佳降解条件为温度35℃，pH，8.体系中额外添加有机碳能提高菌株的降解效率.降解效应的模拟试验结果表明，菌株PIPA-6能在50L模拟罐中稳定发挥降解作用，制药废水中化学需氧量（COD）和铵态氮含量显著降低（P<0.05），哌嗪降解率在30d达98%.宏基因组测序证实该菌株能在水体中稳定定殖，改变了污水中的微生物群落结构.本研究中所获菌株充实了哌嗪降解菌种资源库，实验结果为菌株的实际开发应用提供了初步理论依据.

Isolation and screening of piperazine degrading bacterium PIPA-6 and its degradation characteristics

Piperazine-degrading strain PIPA-6was isolated from the soil around a pharmaceutical plant in this study, the strain could grow in medium with piperazine as the sole energy source, and the degradation rate for 100mg/L of piperazine reached 100% within 30h. Strain PIPA-6 was finally identified as Paenarthrobacter nicotinovorans based on the analysis of morphological observation, physiological and biochemical tests, as well as 16s rDNA sequencing. Strain PIPA-6 could grow in a wide range of temperatures (10~40℃) and pH (5~10), with excellent sodium salt tolerance (50g/L) and high piperazine resistance (300mg/L). The optimum degradation was achieved at 35℃, pH,8. The degradation efficiency of the strain could be significantly improved by adding organic carbons.Simulation experiments showed that strain PIPA-6played a vital role in piperazine degradation in 50L simulation tank, the parameter of chemical oxygen demand(COD) and the content of ammonium nitrogen in pharmaceutical wastewater were significantly reduced(P<0.05).Degradation rate of strain PIPA-6 for piperazine was up to 98% in 30d. Metagenomics analysis confirmed that the strain could successfully colonize in the wastewater and shape new microbial community structure compared with the initial one. The strain obtained in this study enriched the resource of the piperazine-degrading strains, and the experimental results provided a preliminary theoretical basis for the development and practical application of the strain.