Document Detail

Accumulation and fate of green fluorescent labeled Escherichia coli in laboratory-scale drinking water biofilters.
MedLine Citation:
PMID:  16904721     Owner:  NLM     Status:  MEDLINE    
Biological filters combining microbial activity and rapid sand filtration are used in drinking water treatment plants for enhanced biodegradable organic matters (BOM) removal. Biofilms formed on filter media comprised of bacteria enclosed in a polymeric matrix are responsible for the adsorption of BOM and attachment of planktonic microorganisms. This study investigated the removal of Escherichia coli cells injected into laboratory-scale biofilters and the role of biofilm in retaining the injected E. coli. Green fluorescent protein was used as a specific marker to detect and quantify E. coli in the biofilms. About 35% of the total injected E. coli cells were observed in the filter effluents, when initial cell concentrations were measured at 7.4 x 10(6) CFU/mL and 1.6 x 10(7) CFU/mL in two separate experiments. The results from real-time PCR and plate count analysis indicated that 95% of the E. coli retained inside the filters were either non-viable or could not be recovered by colony counting techniques. Injected cells were unevenly distributed inside the filter with more than 70% located at the top 1/5 of the filter. Images obtained from an epifluorescent microscope showed that E. coli cells were embedded inside the biofilm matrix and presented mainly as microcolonies intertwined with other microorganisms, which was consistent with findings from standard plate count methods and qPCR.
J Li; S McLellan; S Ogawa
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2006-08-14
Journal Detail:
Title:  Water research     Volume:  40     ISSN:  0043-1354     ISO Abbreviation:  Water Res.     Publication Date:  2006 Sep 
Date Detail:
Created Date:  2006-08-28     Completed Date:  2007-01-18     Revised Date:  2007-12-03    
Medline Journal Info:
Nlm Unique ID:  0105072     Medline TA:  Water Res     Country:  England    
Other Details:
Languages:  eng     Pagination:  3023-8     Citation Subset:  IM    
Department of Civil Engineering and Mechanics, University of Wisconsin-Milwaukee, EMS 784, Milwaukee, WI 53201, USA.
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MeSH Terms
Clinical Laboratory Techniques / instrumentation
Colony Count, Microbial
Escherichia coli / growth & development*,  isolation & purification
Filtration / instrumentation
Green Fluorescent Proteins / analysis*
Microscopy, Fluorescence
Staining and Labeling
Water Microbiology*
Water Purification / instrumentation*,  methods
Grant Support
Reg. No./Substance:
147336-22-9/Green Fluorescent Proteins

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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