Parry, Jackie D. and Heaton, Karen and Drinkall, Janice and Jones, Harriet L. J. (2001) The feasibility of using GFP-expressing Escherichia coli, coupled with fluorimetry, to determine protozoan ingestion rates. FEMS Microbiology Ecology, 35 (1). pp. 11-17. ISSN 0168-6496Full text not available from this repository.
The feasibility of using a live Escherichia coli population, which had been engineered to express the green fluorescent protein (GFP), coupled with fluorimetry, was tested as a means for determining protozoan ingestion rates. Its potential use was based on evidence that once cells are acidified, e.g. in a food vacuole, the fluorescence is lost. Of the 29 protozoa tested, over 85% ingested the GFP-expressing E. coli and a detailed experiment with the ciliate Tetrahymena pyriformis was carried out, principally to assess the performance of the live bacterium against two commonly used surrogate prey, i.e. fluorescently labelled bacteria (FLB) and fluorescently labelled microspheres (FLMs). A decrease in GFP-expressing E. coli fluorescence and, hence, concentration, was recorded by fluorimetry and epifluorescence microscopy, with calculated ingestion rates being equivalent. A higher ingestion rate was determined by counting the number of fluorescent E. coli within the ciliate over 120 s, but this was equivalent to that obtained for the stained E. coli using the same direct method of analysis. However, the ciliate was shown to process the stained and unstained E. coli cells differently, with only the latter resulting in an increase in ciliate abundance.
|Journal or Publication Title:||FEMS Microbiology Ecology|
|Uncontrolled Keywords:||Protozoan ingestion ; GFP-expressing Escherichia coli ; Fluorescently labelled microsphere ; Fluorescently labelled bacteria ; Fluorimetry|
|Subjects:||Q Science > QH Natural history > QH301 Biology|
|Departments:||Faculty of Health and Medicine > Biomedical & Life Sciences|
|Deposited By:||Dr Jackie Parry|
|Deposited On:||03 Jun 2008 13:35|
|Last Modified:||26 Jul 2012 18:34|
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