Abstract: Batch experiments were conducted in order to investigate the effects of extra carbon sources on benzo[a]pyrene (BaP) biodegradation by Bacillus pumilus strain Bap9, which was isolated from polluted soil collected from open-air barbecue market. In the culture system under initial BaP concentration of 40 mg/L, the addition of sucrose, glucose, maltose reduced the degradation rates, the presence of soluble starch had no obvious effect on the biodegradation, while the supplement of sodium acetate increased by 8.8% of the degradation rates most effectively. However, if the concentrations were too high, sodium acetate would show the inhibition of biodegradation. The supplementation of phenanthrene (Phe), was more effective on increasing the degradation rate than sodium acetate of the same concentration. The biodegradation rate of BaP increased 26.4% after a 20 days incubation period , while Phe of 40 mg/L was used as the co-metabolism substrate.

Key words: Benzo[a]pyrene (BaP), biodegradation, carbon source, co-metabolism, Bacillus pumilu

摘要： 采用从受户外烧烤影响的土壤中分离出的苯并[a]芘降解菌Bacillus pumilus strain Bap9, 利用摇床实验研究了不同外加碳源对其生长和苯并[a]芘降解性能的影响。结果表明, 苯并[a]芘初始浓度为40 mg/L时, 蔗糖、葡萄糖、麦芽糖的存在会抑制菌株对苯并[a]芘的降解, 可溶性淀粉的影响不明显。以醋酸钠为外加碳源可明显促进菌株的降解作用, 添加40 mg/L的醋酸钠, 20天后可将菌株Bap9的降解率提高了8.8%, 但过量的碳源会抑制菌株对苯并[a]芘的降解。添加适量的低分子量菲(PAH)作为共代谢底物, 菲的促进作用大于同浓度的醋酸钠, 添加40 mg/L的菲, 20天后菌株对苯并[a]芘的降解率提高了26.4%。

关键词: 苯并[a]芘, 微生物降解, 碳源, 共代谢, Bacilluspumilus