Grantee Research Project Results
2005 Progress Report: Cyanobacteria and Cyanotoxins in Water Supply Reservoirs – to Develop and Validate a Microarray to Test for Cyanobacteria and Cyanotoxin Genes in Drinking Water Reservoirs as an Aid to Risk Assessment and Management of Water Supplies
EPA Grant Number: R831627Title: Cyanobacteria and Cyanotoxins in Water Supply Reservoirs – to Develop and Validate a Microarray to Test for Cyanobacteria and Cyanotoxin Genes in Drinking Water Reservoirs as an Aid to Risk Assessment and Management of Water Supplies
Investigators: Rublee, Parke , Henrich, Vincent C. , Burkholder, Joann M.
Current Investigators: Rublee, Parke , Henrich, Vincent C. , Burkholder, Joann M. , Glasgow, Howard
Institution: University of North Carolina at Greensboro , North Carolina State University
EPA Project Officer: Aja, Hayley
Project Period: November 1, 2004 through October 31, 2007 (Extended to April 30, 2008)
Project Period Covered by this Report: November 1, 2004 through October 31, 2005
Project Amount: $594,982
RFA: Microbial Risk in Drinking Water (2003) RFA Text | Recipients Lists
Research Category: Drinking Water , Human Health , Water
Objective:
The objective of this research project is to develop and validate a gene microarray for the detection of cyanobacteria and cyanotoxin genes in drinking water reservoirs. The microarray can be used to monitor drinking water supplies as an aid to risk assessment and management.
Progress Summary:
We were able to begin sample collections from targeted water supply reservoirs during the summer of 2004, prior to the beginning of the project period. Collections were made monthly during summer months in 2004 and 2005. Small subunit DNA clone libraries were generated for selected samples using cyanobacteria-specific primers. Up to 87 clones were generated in libraries from four different lakes that had high cyanobacterial diversity during 2004-2005. Sequences of 700 bp amplicons indicated the presence of Synechococcus, Cylindrospermopsis, Anabaena, and Limnothrix spp., as well as many unidentified sequences (< 97% similarity with known GenBank entries). Overall, there were 18 taxa that were represented by multiple clones in the libraries and 94 unique sequences. In some cases, sequences were not able to be resolved to a discrete taxonomic category (i.e., alignments suggested multiple matches at high similarity) and additional sequencing will be undertaken. Primers and probes have been designed and purchased to 17 of the most common taxa found in our samples (some identified to species, some novel), and empirical testing of primers and probes is underway. An additional 25 probes have been derived from literature reports, including some to known toxin genes. Reverse compliments of all probes also will be assessed as part of the validation process. We also are developing a novel approach for rapid validation of array probes.
Cyanobacteria counts were determined in selected reservoirs where blooms occurred during 2005. Microcystin concentrations were determined in all sampled reservoirs. During 2005, concentrations were nearly always less than 0.05 μg L-1, although concentrations in one central North Carolina reservoir rose to 0.08 μg L-1 in August.
Development of the gene microarray will provide a research tool for aquatic scientists to identify factors that promote growth of different cyanobacterial species and their toxins. This prototype will serve as an early warning system to detect the presence of potentially harmful cyanobacteria and their toxins which should be of use to water supply managers to reduce health risks. This prototype will also serve as the basis for development of a more user-friendly real-time (or near real-time) monitoring platform.
Future Activities:
During Year 2 of the project, we will: (1) continue field sampling during 2006, including evaluation of the phytoplankton and especially the cynaobacterial community and assessment of microcystin concentrations; (2) generate additional clone libraries from targeted samples with high cyanobacterial diversity or blooms to assure adequate understanding of the cyanobacterial diversity and key bloom taxa that will serve as our targets in North Carolina drinking water reservoirs; (3) generate additional probe and primers sets to both known and novel cyanobacterial taxa from our samples; (4) continue testing and validation of probe and primer sets, with refinement/modification of the probe and primer sequences as indicated by empirical testing; and (5) print and test the first version of a printed array.
Journal Articles:
No journal articles submitted with this report: View all 33 publications for this projectSupplemental Keywords:
aquatic organisms, cyanobacteria, drinking water system, drinking water contaminants, early warning, gene microarray assay, microbial contamination, microbial risk assessment, monitoring, aquatic ecosystems, ecology, innovative technology, indicators, drinking water, risk assessment,, RFA, Scientific Discipline, INTERNATIONAL COOPERATION, Water, Health Risk Assessment, Environmental Chemistry, Drinking Water, Environmental Engineering, Environmental Monitoring, microbial contamination, gene microarray assay, early warning, microbial risk assessment, monitoring, aquatic organisms, drinking water system, drinking water contaminants, other - risk assessment, cyanobacteriaRelevant Websites:
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.