木糖氧化无色杆菌P1对芘降解的研究及其在两相分配生物反应系统中的应用

采用富集培养技术筛选芘降解微生物，得到一株纯培养条件下可以有效降解芘的细菌，命名为P1，经鉴定为木糖氧化无色杆菌（Achromobacter xylosoxidans）。研究了培养条件对P1降解的影响，在此基础上考察了其在两相分配生物反应系统中对芘的降解。研究结果表明：菌株P1可以有效降解培养体系中的芘，在芘的初始质量浓度为100 mg/L，pH为7，温度为30 ℃时，对芘的降解效果最好；在两相分配生物反应系统中菌株P1对芘的降解速率大于单相反应系统，且降解率受到非水相类型和芘初始浓度的影响，其中以十一醇为有机相的双相反应系统较十二烷和硅油更能促进生物降解，5 d内降解率为78.8%。

Degradation of pyrene by Achromobacter xylosoxidans P1 and its application in a two-phase partitioning bioreactor

A pyrene degrading strain has been isolated by enrichment culture, and identified as Achromobacter xylosoxidans and denoted as the P1 strain. The pyrene biodegradation induced by P1 was investigated in a two-liquid phase partitioning bioreactor (TPPB). It was found that pyrene was effectively degraded by the P1 strain, with the optimum conditions being an initial concentration of pyrene of 100 mg/L, pH of 7, and cultivation temperature of 30 ℃ without the addition of an organic phase. Under these conditions, the extent of pyrene degradation increased significantly in the TPPB system. In the TPPB system, the degradation ratio, which depends on the type of organic phase and the initial concentration of pyrene, achieved by using the P1 strain were much higher than those in the treatment processes without any organic phase. Undecanol was found to be a more effective organic phase than either dodecane or silicone oil, giving a degradation ratio of 78.8% after 5 days.