title: [Bioaugmentation of bioreactors with a pJP4 receiving transconjugant to enhance the removal of 2,4-D].
abstract: The paper first investigated horizontal transfer of a conjugative plasmid pJP4 to two pure strains of E. coli DH5alpha and Alcaligenes sp., and a mixed culture of aerobic granular sludge, respectively. With a pJP4 receiving transconjugant Alcaligenes sp. :: pJP4 as the bioaugmented bacteria, bioaugmentation experiments were conducted in an aerobic granular sludge reactor and a biofilm reactor, respectively, to enhance the removal of a recalcitrant compound 2,4-dichlorophenoxyacetic acid(2,4-D). Results showed that pJP4 successfully transferred to E. coli DH5alpha, Alcaligenes sp. and the mixed culture of aerobic granules. For the aerobic granular sludge reactor operated in semi-continuous mode and fed with 2,4-D sole carbon source wastewater, bioaugmentation with Alcaligenes sp. : : pJP4 increased 2,4-D average removal rate significantly with an enhancement of 12% -1 498%. For the biofilm reactor operated in sequence batch mode and fed with mixed carbon sources wastewater, supplementation of the transconjugant reduced system start-up time greatly from 16 d to 5 d. It is a feasible strategy to obtain special degradative transconjugants through gene augmentation and put them into bioreactor as bioaugmentation agent to enhance the removal of some specific pollutants.
authors.affiliation: State Key Laboratory of Water Environment Simulation of Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, China. xchquan@bnu.edu.cn
authors.forename: Xiang-Chun
authors.initials: XC
authors.lastname: Quan
authors.forename: Hua
authors.initials: H
authors.lastname: Tang
authors.forename: Jing-Yun
authors.initials: JY
authors.lastname: Ma
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000302:isolation & purification* / Q000378:metabolism; D000332:Aerobiosis; D000421:Alcaligenes / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D003227:Conjugation, Genetic; D004926:Escherichia coli / Q000378:metabolism; D006540:Herbicides / Q000302:isolation & purification / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D006540:Herbicides; D015084:2,4-Dichlorophenoxyacetic Acid