title: Simultaneous biodegradation of Ni-citrate complexes and removal of nickel from solutions by Pseudomonas alcaliphila.
abstract: The objective of this study was to study the simultaneous biodegradation of Ni-citrate complexes and removal of Ni from solutions by Pseudomonas alcaliphila. Adding excess citrate to 1:1 Ni-citrate complexes promoted the degradation of the complexes and removal of Ni. The alkaline pH generated by the metabolism of excess citrate caused partial dissociation of citrate from the Ni-citrate complexes, allowing degradation, and the released Ni was removed through bioaccumulation and precipitation. Addition of Fe(3+) enhanced the degradation of Ni-citrate complexes and removal of Ni from solutions. The displacement of Ni from recalcitrant Ni-citrate complexes by Fe(3+) and subsequent biodegradation of the degradable Fe(III)-citrate complex resulted in complete metabolism of citrate. The almost complete removal of Ni (>98%) can be attributed to the combination of coprecipitation with Fe(3+), bioaccumulation and precipitation. P. alcaliphila potentially could be applied in the treatment of effluent containing Ni-citrate complexes.
authors.affiliation: College of Life Sciences, Sichuan University, Chengdu 610064, China.
authors.forename: Junwei
authors.initials: J
authors.lastname: Qian
authors.forename: Daping
authors.initials: D
authors.lastname: Li
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Zhan
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.forename: Wentao
authors.initials: W
authors.lastname: Su
authors.forename: Ping
authors.initials: P
authors.lastname: Gao
mesh_terms: D001673:Biodegradation, Environmental / Q000187:drug effects; D018533:Biomass; D019343:Citric Acid / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007501:Iron / Q000494:pharmacology; D007700:Kinetics; D009532:Nickel / Q000302:isolation & purification*; D011549:Pseudomonas / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D012996:Solutions; D013052:Spectrometry, X-Ray Emission
chemical_list: D012996:Solutions; D019343:Citric Acid; D009532:Nickel; D007501:Iron