Open AccessBiofilm formation of a bacterial consortium on linuron at micropollutant concentrations in continuous flow chambers and the impact of dissolved organic matter
Author(s) -
Horemans Benjamin,
Hofkens Johan,
Smolders Erik,
Springael Dirk
Publication year - 2014
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/1574-6941.12280
Subject(s) - biofilm , environmental chemistry , microbial consortium , biomass (ecology) , dissolved organic carbon , organic matter , biology , microbiology and biotechnology , food science , chemistry , bacteria , microorganism , ecology , genetics
Bacterial multispecies biofilms are catalysts for pollutant degradation in aqueous ecosystems. Their activity in systems where xenobiotics occur as micropollutants (μg L −1 level) and natural dissolved organic matter provides carbon and energy instead remains uncharacterized. Biofilm formation of a bacterial consortium consisting of the linuron‐degrading V ariovorax sp. WDL 1 and metabolite‐degrading strains C omamonas sp. WDL 7 and H yphomicrobium sp. WDL 6 at micropollutant linuron concentrations and the impact of auxiliary carbon sources on degradation and biofilm composition were investigated. Biofilms formed at concentrations of 1000, 100, and 10 μg L −1 linuron. The highest biomass, organized in mixed‐species mounds, was observed at 1000 μg L −1 linuron, while at 100 and 10 μg L −1 , thin layers of cells occurred. Linuron removal efficiencies decreased from c . 85% when fed with 100 and 1000 μg L −1 linuron to 30% in case of 10 μg L −1 linuron due to reduced specific activity. Biofilms grown on 10 μg L −1 linuron were subsequently fed with easily and less degradable carbon sources in addition to 10 μg L −1 linuron. Although co‐feeding with more degradable C‐sources increased biofilm biomass, linuron removal remained 30%. Calculations based on biofilm volume measurements pointed toward reduced specific activity, compensated by a higher biomass. Uncertainties about biofilm heterogeneity and cell volume can undo this explanation.