title: A novel strategy for acetonitrile wastewater treatment by using a recombinant bacterium with biofilm-forming and nitrile-degrading capability.
abstract: 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 biofilm-forming bacterium (Bacillus subtilis N4) that expressed the recombinant protein upon isopropylthio-β-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.
authors.affiliation: College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China. Electronic address: lcy032002@163.com.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Li
authors.affiliation: College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
authors.forename: Zhenlei
authors.initials: Z
authors.lastname: Yue
authors.affiliation: College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
authors.forename: Fengzhao
authors.initials: F
authors.lastname: Feng
authors.affiliation: Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
authors.forename: Chuanwu
authors.initials: C
authors.lastname: Xi
authors.affiliation: College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
authors.forename: Hailian
authors.initials: H
authors.lastname: Zang
authors.affiliation: College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
authors.forename: Xuejiao
authors.initials: X
authors.lastname: An
authors.affiliation: College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
authors.forename: Keran
authors.initials: K
authors.lastname: Liu
mesh_terms: D000097:Acetonitriles / Q000378:metabolism*; D000619:Aminohydrolases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology; D004790:Enzyme Induction; D007544:Isopropyl Thiogalactoside / Q000235:genetics / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D012240:Rhodococcus / Q000235:genetics*; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D000097:Acetonitriles; D000619:Aminohydrolases; D001426:Bacterial Proteins; D007544:Isopropyl Thiogalactoside; D011994:Recombinant Proteins; D062065:Wastewater; D014874:Water Pollutants, Chemical; C021867:nitrilase; C032159:acetonitrile
keywords: Acetonitrile; Biofilm-forming bacteria; Nitrilase; Recombinant bacterium; Wastewater treatment