• 关键词：乙腈  Rhodococcus sp.BX2  降解特性  腈水合酶  腈水解酶  酰胺酶

• 基金项目：黑龙江省自然科学基金(No.C201021);黑龙江省博士后科研启动资助基金(No. LBH-Q09158); "十一五"国家科技支撑计划(No.2007BAD87B03);黑龙江省教育厅课题项目(No.11541015)

• 孙晶
• 东北农业大学资源与环境学院, 哈尔滨 150030

• 熊明华
• 东北农业大学资源与环境学院, 哈尔滨 150030

• 成小松
• 哈尔滨医科大学第一临床医学院, 哈尔滨 150001

• 李悦
• 东北农业大学资源与环境学院, 哈尔滨 150030

• 臧海莲
• 伊春林业科学院,伊春 153000

• 李春艳
• 东北农业大学资源与环境学院, 哈尔滨 150030

• 摘要：对Rhodococcus sp.BX2菌降解乙腈的特性及其降解途径进行了研究.结果显示,在底物浓度为800 mg·L^-1,接种量为1.0%,培养温度为35 ℃,环境pH为7.5的条件下,16 h时 Rhodococcus sp.BX2菌对乙腈的降解率为95.98%;添加葡萄糖可在培养初期加快Rhodococcus sp.BX2菌的生长和对乙腈的降解,蔗糖、乙酰胺和尿素对其影响不大.将BX2菌接种到含有高乙腈浓度(25000 mg·L^-1)的合成废水中,培养180 h后, 乙腈降解率可达88.59%.在催化反应60 min后,Rhodococcus sp.BX2腈水合酶与腈水解酶的总酶活可达到422.81 U·mL^-1,对其相关基因序列的分析结果表明,Rhodococcus sp.BX2中同时存在腈水解酶基因和腈水合酶基因,因此,确定乙腈的降解主要由腈水合酶途径完成,可能同时存在腈水解酶的降解途径.

• Abstract：The characteristics and pathway of acetonitrile degradation by Rhodococcus sp.BX2 were investigated in this study. Results showed that with the initial acetonitrile concentration of 800 mg·L^-1, the degradation rate was 95.98% in 16 hours under the condition of inoculum 1.0%, 35 ℃ and pH value 7.5.Glucose could accelerate the degradation of acetonitrile in the initial period, while sucrose, acetamide and urea had slight impact. The degradation rate could reach 88.59% when BX2 was cultured in the synthetic wastewater with high concentration of acetonitrile (25000 mg·L^-1) for 180 hours. Total enzyme activities was 422.81 U·mL^-1 when incubated for 60 minutes. The results of related genes sequence showed that Rhodococcus sp BX2 had both nitrile hydrolase gene and nitrile hydratase gene. The degradation pathway of acetonitrile by Rhodococcus sp. BX2 was mainly nitrile hydratase (NHase), with possible pathway of the nitrile hydrolase.

• Key words：acetonitrile  Rhodococcus sp. BX2  degrading characteristics  nitrile hydrolase  nitrile hydratase  amidase

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