A novel strategy for acetonitrile wastewater treatment by using a recombinant bacterium with biofilm-forming and nitrile-degrading capability

作者：Li, Chunyan^*; Yue, Zhenlei; Feng, Fengzhao; Xi, Chuanwu; Zang, Hailian; An, Xuejiao; Liu, Keran

来源：Chemosphere, 2016, 161: 224-232.

DOI：10.1016/j.chemosphere.2016.07.019

• Nitrilase
• Biofilm-forming bacteria
• Recombinant bacterium
• Acetonitrile
• Wastewater treatment

There is a great need for efficient acetonitrile removal technology in wastewater treatment to reduce the discharge of this pollutant in untreated wastewater. In this study, a nitrilase gene (nit) isolated from a nitrile-degrading bacterium (Rhodococcus rhodochrous BX2) was cloned and transformed into a biofilmforming bacterium (Bacillus subtilis N4) that expressed the recombinant protein upon isopropylthio-beta-galactoside (IPTG) induction. The recombinant bacterium (B. subtilis N4-pHT01-nit) formed strong biofilms and had nitrile-degrading capability. Further testing demonstrated that biofilms formed by B. subtilis N4-pHT01-nit were highly resistant to loading shock from acetonitrile and almost completely degraded the initial concentration of acetonitrile (800 mg L-1) within 24 h in a moving bed biofilm reactor (MBBR) after operation for 35 d. The bacterial composition of the biofilm, identified by high throughput sequencing, in a reactor in which the B. subtilis N4-pHT01-nit bacterium was introduced indicated that the engineered bacterium was successfully immobilized in the reactor and became dominant genus. This work demonstrates that an engineered bacterium with nitrile-degrading and biofilm-forming capacity can improve the degradation of contaminants in wastewater. This approach offers a novel strategy for enhancing the biological oxidation of toxic pollutants in wastewater.

• 出版日期2016-10
• 单位东北农业大学