Bioaugmentation of a sequencing batch biofilm reactor by horizontal gene transfer

被引:33
作者
Bathe, S
Mohan, TVK
Wuertz, S
Hausner, M
机构
[1] Tech Univ Munich, Inst Water Qual Control & Waste Management, D-85748 Garching, Germany
[2] BARC Facil, Water & Steam Chem Lab, Kalpakkam 603012, Tamil Nadu, India
[3] Univ Calif Davis, Dept Civil & Environm Engn, Davis, CA 95616 USA
关键词
bioaugmentation; catabolic plasmid pJP4; conjugation; 2,4-dichlorophenoxyacetic acid (2,4-D); PCR-DGGE; sequencing batch biofilm reactor (SBBR);
D O I
10.2166/wst.2004.0875
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Bioaugmentation by introduction of catabolic genes residing on mobile genetic elements into the microbial community of a soil or wastewater environment might be an alternative to bioaugmentation by addition of bacterial cells with chromosomally encoded catabolic genes. This study investigates the possibility to enhance degradation of the xenobiotic model compound 2,4-dichlorophenoxyacetic acid in a sequencing batch biofilm reactor (SBBR) by using the conjugative plasmid pJP4 carrying genes for 2,4-D degradation. After introduction of a plasmid donor strain to a lab-scale SBBR operated without 2,4-D, the number of plasmid-carrying cells first dropped, and then increased after switching to 2,4-D as the sole carbon source. The donor cells were unable to grow in the applied synthetic wastewater with 2,4-D as the sole carbon source. Transconjugants could be detected both by culture-dependent and culture-independent methods in the 2,4-D degrading biofilm. In contrast to 90% 2,4-D degradation in the bioaugmented reactor within 40 h, a control reactor which had not received the plasmid still contained 60% of the initial 2,4-D concentration after 90 h. This experiment clearly demonstrates the introduction of 2,4-D degradative genes into a microbial biofilm and indicates that horizontal gene transfer is a promising tool for bioaugmentation of reactors treating wastewater.
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页码:337 / 344
页数:8
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