Open AccessBiological Filtration Limits Carbon Availability and Affects Downstream Biofilm Formation and Community Structure
Author(s) -
Chee Meng Pang,
Wen Tso Liu
Publication year - 2006
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.02982-05
Subject(s) - biofilm , terminal restriction fragment length polymorphism , microtiter plate , microbiology and biotechnology , betaproteobacteria , environmental chemistry , biology , effluent , chemistry , total organic carbon , bacteria , food science , 16s ribosomal rna , chromatography , restriction fragment length polymorphism , environmental engineering , environmental science , biochemistry , polymerase chain reaction , genetics , actinobacteria , gene
Carbon removal strategies have gained popularity in the mitigation of biofouling in water reuse processes, but current biofilm-monitoring practices based on organic-carbon concentrations may not provide an accurate representation of the in situ biofilm problem. This study evaluated a submerged microtiter plate assay for direct and rapid monitoring of biofilm formation by subjecting the plates to a continuous flow of either secondary effluent (SE) or biofilter-treated secondary effluent (BF). This method was very robust, based on a high correlation (R 2 = 0.92) between the biomass (given by theA 600 in the microtiter plate assay) and the biovolume (determined from independent biofilms developed on glass slides under identical conditions) measurements, and revealed that the biomasses in BF biofilms were consistently lower than those in SE biofilms. The influence of the organic-carbon content on the biofilm community composition and succession was further evaluated using molecular tools. Terminal restriction fragment length polymorphism analysis of 16S rRNA genes revealed a group of pioneer colonizers, possibly represented bySphingomonadaceae andCaulobacter organisms, to be common in both SE and BF biofilms. However, differences in organic-carbon availabilities in the two water samples eventually led to the selection of distinct biofilm communities. Alphaproteobacterial populations were confirmed by fluorescence in situ hybridization to be enriched in SE biofilms, whileBetaproteobacteria were dominant in BF biofilms. Cloning analyses further demonstrated that microorganisms adapted for survival under low-substrate conditions (e.g.,Aquabacterium ,Caulobacter , andLegionella ) were preferentially selected in the BF biofilm, suggesting that carbon limitation strategies may not achieve adequate biofouling control in the long run.