一株高效丙烯腈降解细菌Rhodococus rhodochrous BX2的丙烯腈降解条件优化

Optimization of acrylonitrile biodegradation by acrylonitrile-degrading bacterium Rhodococus rhodochrous BX2

【目的】以丙烯腈为目标污染物,利用实验室已筛选获得的一株高效腈降解菌Rhodococus rhodochrous BX2,研究其对丙烯腈的降解特性,优化降解条件以提高菌株对丙烯腈的降解能力。【方法】通过单因素试验和响应面分析相结合的方法优化Rhodococus rhodochrous BX2对丙烯腈的降解条件。考察外加碳、氮源对BX2的生长及丙烯腈降解的影响,并确定其在丙烯腈合成废水中对丙烯腈的处理效果。【结果】菌株BX2优化后的最佳降解条件为:底物浓度403.51 mg/L、p H 7.44、温度34.46°C,在此条件下丙烯腈的降解率为95.1%。外加碳源为葡萄糖,或外加氮源为氯化铵对菌株生长及丙烯腈降解有明显的促进作用。菌株Rhodococus rhodochrous BX2能够高效降解合成废水中的丙烯腈,在30 h时其丙烯腈降解率可达89.4%。【结论】降解条件优化以及外源物质的添加强化了菌株对丙烯腈合成废水的处理效果,为生物法处理丙烯腈废水新方法的开发提供技术支持。

[Objective] To improve acrylonitrile biodegradation efficiency, we studied acrylonitrile degradation characteristics of a nitrile-degrading bacterium Rhodococus rhodochrous BX2 isolated by our laboratory. [Methods] Single factor test and response surface methodology were used to optimize the biodegradation conditions. At the same time, the effects of various additional carbon and nitrogen resources on cell growth and acrylonitrile degradation were studied, as well as cell growth and degradation rate of strain BX2 in acrylonitrile synthetic wastewater. [Results] The maximum biodegradation rate（95.1%） was obtained under optimal degradation conditions（substrate concentration 403.51 mg/L, p H 7.44, temperature 34.46 ℃）. The cell growth and degradation effectiveness can be obviously improved by addition of carbon sources（glucose） or nitrogen source（ammonium chloride）. The degradation rate of acrylonitrile in acrylonitrile synthetic wastewater reached 89.4% after 30 h. [Conclusion] The acrylonitrile biodegradation efficiency of Rhodococus rhodochrous BX2 in acrylonitrile synthetic wastewater was enhanced by optimizing biodegradation conditions and the addition of exogenous substance. This work provides technical support for the development and application of new techniques in biological treatment of acrylonitrile wastewater.