• 关键词：氮单胞菌  苯并芘  降解  共代谢

• 基金项目：江苏省社会发展项目资助(BS2002044)

• 盛下放
• 南京农业大学生命科学学院, 农业部农业环境微生物工程重点开放实验室, 南京 210095

• 何琳燕
• 南京农业大学生命科学学院, 农业部农业环境微生物工程重点开放实验室, 南京 210095

• 胡凌飞
• 南京农业大学生命科学学院, 农业部农业环境微生物工程重点开放实验室, 南京 210095

• 摘要：从被石油污染的土壤样品中,以苯并[a]芘为唯一碳源反复驯化,分离筛选出1株高效降解苯并[a]芘的菌株JL-14.经形态及生理生化特征分析,初步鉴定属于氮单胞菌属(Azomonas).菌株JL-14在苯并[a]芘浓度为5mg·L^-1,28℃振荡培养10d,苯并[a]芘的降解率达到48.9%.培养基初始pH值分别为4、6、8、10时,28℃振荡培养10d,苯并[a]芘的降解率分别为7.1%,24.8%,49.6%和25.9%.JL-14在苯并[a]芘浓度分别为10mg·L^-1与20mg·L^-1的条件下,28℃振荡培养10d,苯并[a]芘的降解率分别为38.2%与27.6%.Zn²⁺(200mg·L^-1)、Cd²⁺(50mg·L^-1)与Pb²⁺(200mg·L^-1)不影响JL-14对苯并[a]芘的降解作用,但Cu²⁺(50mg·L^-1)、Cr²⁺(50mg·L^-1)对JL-14有毒性;菲和蔗糖均可促进菌株JL-14对苯并[a]芘的降解作用.

• Abstract：The purpose was to characterize a newly isolated strain of Azomonas sp.obtained from petroleum hydrocarbon-contaminated soils and designated JL-14, with respect to its ability to degrade benzo[a]pyrene. Seventeen bacteria were isolated by repeated subculture in liquid medium with benzo[a]pyrene as carbon source and an isolate (isolate 14) from best growth around benzo[a]pyrene crystals on solid medium was obtained. The strain was identified as Azomonas sp. based on its morphological and physio-biochemical characteristics. The effects of initial benzo[a]pyrene concentrations, initial pH, heavy metal ions and the addition of phenanthrene and sucrose on biodegradation potential were also investigated. The enriched bacterial strain JL-14 could use benzo[a]pyrene as the sole carbon source for growth and degrade the benzo[a]pyrene accordingly. Asignificant positive relationship was found between bacterial growth and percentages of benzo[a]pyrene degradation. In a mineral salts medium with 5 mg·L^-1 benzo[a]pyrene, the highest degradation of benzo[a]pyrene of 49.6% (pH8) was obtained after 10 days at 28℃.The degradation rate range was 27.6%～48.9% in the medium with 5～20 mg·L^-1 benzo[a]pyrene. Zn ²⁺(200 mg·L^-1)、Cd ²⁺(50 mg·L^-1)and Pb ²⁺(200 mg·L^-1)did not inhibit growth and biodegradation of benzo[a]pyrene of the strain, but the inhibitory effect was found on Cu ²⁺ (50 mg·L^-1)and Cr ²⁺ (50 mg·L^-1). Supplementation of benzo[a]pyrene-containing cultures with phenanthrene and sucrose had significant effects on benzo[a]pyrene degradation. These findings indicated that this isolate of Azomonas sp. might be useful for bioremediation of soils contaminated with benzo[a]pyrene.

• Key words：Azomonas sp.  benzo[a]pyrene  degradation  co-metabolism

• 
  摘要点击次数： 1707 全文下载次数： 3361