Abstract:

An enrichment method was used to enrich functional bacteria in continuous fluid using porous carrier, which simulated dynamic environments. This method was developed based on the theory of enrichment culture and medium retain manner technique. Four bacteria strains were isolated from sewer using benzo[a]pyrene (BaP) to provide energy and carbon, among them a single strain of bacteria isolated, identified as Acinetobacter sp. Bap30 according to 16S rRNA gene sequence and identification of its physiological and biochemical characteristics, grew in mineral salt medium with 40 mg/L BaP and degraded 28.7% BaP after 20 days of incubation. The BaP-degradation function of Acinetobacter genus has not been previously reported in the literature. Addition of extra carbon sources (in particular sucrose) and phenanthrene (a low molecular weight polycyclic aromatic hydrocarbon) influenced the degradation rate, which was effectted by the type and concentration. The present study is of practical importance in environmental engineering, given that BaP is a highly toxic polycyclic aromatic hydrocarbon (PAH) commonly found in petroleum-polluted soil and industrial discharges such as coking wastewater.

Key words: benzo[a]pyrene (BaP), Acinetobacter sp. Bap30, biodegradation, carbon source, co-metabolism

摘要：

提出一种新的方法, 用于富集苯并[a]芘耐受菌株。该方法使用多孔介质脱脂棉作为载体, 从连续流动的流体——下水道污水中富集菌株。利用介质截留法、富集培养法等理论, 为富集目标微生物提供了最佳条件。以苯并[a]芘为唯一碳源和能源, 从下水道沉积物中分离、筛选出4株苯并[a]芘耐受菌株, 其中一株能在20天内将40 mg/L的苯并[a]芘降解28.7%。通过16S rRNA基因序列分析和部分生理生化特征分析, 鉴定该菌株为Acinetobacter sp. Bap30。这是不动杆菌可降解苯并[a]芘的首次报道。添加其他碳源和低分子量多环芳烃——菲作为共代谢底物, 研究菌株的共代谢作用。研究结果对石油污染的土壤或者焦化废水等工业污水中的高分子量多环芳烃——苯并[a]芘具有非常重要的实践意义。

关键词: 苯并[a]芘, Acinetobacter sp. Bap30, 微生物降解, 碳源, 共代谢