[Plasmid pJP4 mediated gene-augmentation in different systems and its effect on 2,4-D biodegradation].
With pJP4 plasmid carrying genetic engineering bacteria Pseudomonas putida SM1443 :: gfp2x (pJP4 :: dsRed) as the donor, horizontal gene transfer of pJP4 plasmid in 4 isolated pure strains was investigated, and effects of the donor bacteria inoculation on the removal of the target pollutant 2,4-dichlorophenoxyacetic acid (2,4-D) was studied through conducting gene augmentation in activated sludge, biofilm, aerobic granular sludge and river sediment system, respectively. Results showed that plasmid pJP4 could transfer from Pseudomonas putida SM1443 to a broad spectrum of bacteria. Inoculation of pJP4 plasmid carrying donor bacterium apparently promoted the degradation of 2,4-D for all the above four systems. For the activated sludge system (2,4-D initial concentration at 450 mg/L), 66% and 54% removal of 2,4-D was achieved after 143.5 h reaction for the gene augmented and control system, respectively. For the biofilm system with 2,4-D initial concentration at 180 mg/L, 2,4-D removal percentage at 113 h was 99% and 61%, respectively. For aerobic granular sludge system (2,4-D initial concentration at 160 mg/L), 2,4-D was nearly completely removed by 62 h in the gene-augmented system, while the control system only degraded 26% at 66 h. For the system with sediment (2,4-D initial concentration at 2 mg/L), 93% and 69% removal of 2,4-D was obtained at 344 h reaction for the gene augmented and control system, respectively. Confocal laser scanning microscopy (CLSM) analysis revealed the formation and presence of transconjugants in different gene augmentation systems.
State Key Laboratory of Water Environmental Simulation, School of Environment, Beijing Normal University, Beijing 100875, China. xchquan@yahoo.com.cn
Xiang-Chun
XC
Quan
Hua
H
Tang
Yu-Lai
YL
Wang
Meng-Chang
MC
He
D015084:2,4-Dichlorophenoxyacetic Acid / Q000302:isolation & purification / Q000378:metabolism*; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D003227:Conjugation, Genetic; D022761:Gene Transfer, Horizontal; D005818:Genetic Engineering; D007218:Industrial Microbiology; D010957:Plasmids / Q000235:genetics*; D016133:Polymerase Chain Reaction; D016958:Pseudomonas putida / Q000235:genetics* / Q000378:metabolism; D012722:Sewage / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods
D012722:Sewage; D015084:2,4-Dichlorophenoxyacetic Acid