Bioaugmentation of microbial communities in laboratory and pilot scale sequencing batch biofilm reactors using the TOL plasmid.
The aim of this study was to investigate the effectiveness of bioaugmentation and transfer of plasmid pWWO (TOL plasmid) to mixed microbial populations in pilot and laboratory scale sequencing batch biofilm reactors (SBBRs) treating synthetic wastewater containing benzyl alcohol (BA) as a model xenobiotic. The plasmid donor was a Pseudomonas putida strain chromosomally tagged with the gene for the red fluorescent protein carrying a green fluorescent protein labeled TOL plasmid, which confers degradation capacity for several compounds including toluene and BA. In the pilot scale SBBR donor cells were disappeared 84 h after inoculation while transconjugants were not detected at all. In contrast, both donor and transconjugant cells were detected in the laboratory scale reactor where the ratio of transconjugants to donors fluctuated between 1.9 x 10(-1) and 8.9 x 10(-1) during an experimental period of 32 days. BA degradation rate was enhanced after donor inoculation from 0.98 mg BA/min prior to inoculation to 1.9 mg BA/min on the seventeenth day of operation. Survival of a bioaugmented strain, conjugative plasmid transfer and enhanced BA degradation was demonstrated in the laboratory scale SBBR but not in the pilot scale SBBR.
Venkata Mohan
S
S
Institute of Water Quality Control and Waste Management, Technical University of Munich, Am Coulombwall, Garching, Germany. vmohan_s@yahoo.com
Falkentoft
Christina
C
Venkata Nancharaiah
Y
Y
Sturm
Belinda S McSwain
BS
Wattiau
Pierre
P
Wilderer
Peter A
PA
Wuertz
Stefan
S
Hausner
Martina
M
D019905:Benzyl Alcohol; D018441:Biofilms; D019149:Bioreactors; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics; D010957:Plasmids / Q000235:genetics*; D016958:Pseudomonas putida / Q000235:genetics / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*; D000097573:Red Fluorescent Protein
D019905:Benzyl Alcohol; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein