• 关键词：多环芳烃  苯并[a]芘  污染土壤  生物降解  微生物-植物联合修复  根际效应

• 基金项目：中央高校基本科研业务费专项资金；高等学校学科创新引智计划（111计划）（No.T2017002）

• 顾平
• 1. 黑龙江省环境监测中心站, 哈尔滨 150056;2. 中国科学院沈阳应用生态研究所, 沈阳 110016

• 周启星
• 南开大学环境科学与工程学院, 环境污染过程与基准教育部重点实验室/天津市城市生态环境修复与污染防治重点实验室, 天津 300071

• 王鑫
• 南开大学环境科学与工程学院, 环境污染过程与基准教育部重点实验室/天津市城市生态环境修复与污染防治重点实验室, 天津 300071

• 张倩茹
• 中国科学院沈阳应用生态研究所, 沈阳 110016

• 伍跃辉
• 黑龙江省环境监测中心站, 哈尔滨 150056

• 陈威
• 黑龙江省环境监测中心站, 哈尔滨 150056

• 赵伟
• 黑龙江省环境监测中心站, 哈尔滨 150056

• 李博
• 黑龙江省环境监测中心站, 哈尔滨 150056

• 摘要：从长期受多环芳烃（PAHs）污染的土壤中获得1株高效降解菌BB-1，经鉴定为巨大芽孢杆菌Bacillus megaterium.为了考察菌株的降解特性，将10和20 mg·L^-1的苯并[a]芘（B[a]P）加入到培养液中并在30℃下振荡培养8 d.结果表明，BB-1对不同浓度的B[a]P的降解率分别为52.1%和23.5%，B[a]P浓度为10 mg·L^-1时降解效果更优.将不同重金属外加到培养液中，Cu²⁺（50 mg·L^-1）和Cd²⁺（100 mg·L^-1）能在一定程度上影响BB-1对B[a]P的生物降解作用，但菌株仍有很强的耐受性；Zn²⁺（200 mg·L^-1）和Pb²⁺（300 mg·L^-1）会显著影响降解效果.为了研究菌BB-1与植物的联合降解修复作用，通过对比研究将该菌株加入到种植紫茉莉的B[a]P污染土壤中，在未加入BB-1的污染土壤中，紫茉莉在开花期和成熟期对B[a]P的降解率分别为27.42%±1.99%和51.31%±3.06%，在加入BB-1的污染土壤中降解率分别为68.22%±1.21%和77.16%±0.62%，可见加入菌株BB-1后能显著提高紫茉莉对土壤中B[a]P的降解效率.为确定降解作用的菌株来源，分别对比了非根际和根际土壤中的B[a]P含量，发现在开花期和成熟期任何一种处理的根际土中B[a]P残留浓度都小于非根际土，说明土壤中B[a]P的去除主要是源于根际的作用.在植物修复的基础上，添加能耐受一定重金属浓度的高效B[a]P降解菌，能提高B[a]P降解率，有望为日后大规模田间应用提供可靠的技术参数.

• Abstract：An effective degrading bacterium BB-1 which was identified as Bacillus megaterium was obtained from the soil contaminated with polycyclic aromatic hydrocarbons (PAHs) for a long time. In order to investigate the degradation characteristics of the strain,10 mg·L^-1 and 20 mg·L^-1 B[a]P was respectively added to the culture medium at 30℃ for 8 days,and the results showed that the degradation rate for B[a]P by BB-1 was 52.1% and 23.5% respectively,and the degradation ability was better when the added concentration of B[a]P was 10 mg·L^-1. The addition of different heavy metals into the culture medium showed that Cu²⁺ (50 mg·L^-1) and Cd²⁺ (100 mg·L^-1) could affect the biodegradation of B[a]P by BB-1 to a certain extent,however,still with very strong tolerance;Zn²⁺ (200 mg·L^-1) and Pb²⁺ (300 mg·L^-1) significantly affected the degradation of B[a]P. In order to examine the degradation ability by the combination of BB-1 and remediation plants,the strain was added to B[a]P contaminated soil with growing Mirabilis jalapa. The results showed that the degradation rate of B[a]P in the contaminated soil without addition of BB-1 was 27.42%±1.99% and 51.31%±3.06%,respectively,during the flowering period and mature period,and,the degradation rate in the contaminated soil with addition of BB-1 was up to 68.22%±1.21% and 77.16%±0.62%,respectively. It is thus clear that the addition of the strain BB-1 could significantly improve the degradation of B[a]P in the soil. The results also showed that the residual concentration of B[a]P in rhizosphere soil was less than that in non-rhizosphere soil,with any processing during the flowering period and the mature period,in other words,the removal of B[a]P in soil was mainly attributed to the rhizosphere of plants. On the basis of phytoremediation,the addition of highly efficient B[a]P degrading bacteria,which could tolerate a certain concentration of heavy metals,could improve the degradation rate of B[a]P,that is expected to provide the basis for future large-scale field experiment.

• Key words：polycyclic aromatic hydrocarbons (PAHs)  benzo[a]pyrene (B[a]P)  contaminated soil  biodegradation  joint microbiological-phytoremediation  rhizospheric effect

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