[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.
Quan
Xiang-Chun
XC
State Key Laboratory of Water Environmental Simulation, School of Environment, Beijing Normal University, Beijing 100875, China. xchquan@yahoo.com.cn
Tang
Hua
H
Wang
Yu-Lai
YL
He
Meng-Chang
MC
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