Cyano - Cultures  -  Cyanophages  -  Lakes

Background

Toxicity in cyanobacteria is a major concern for a wide number of agencies and organizations, from the World Health Organization to county and city lawmakers world-wide. Cyanobacteria blooms, which consist of large groupings of millions upon millions of organisms are unsightly, odorous, and frequently toxic to livestock, wildlife and humans (Johnston 1). In order to further understand these organisms, track trends and ultimately advise administrators, this web site presents a distillation of the results of one of the labs analyzing cyanobacteria at Oregon State University.

Cyanobacteria represent a huge class of single-celled organisms that are prolific throughout the earth, important as photosynthesizers and nitrogen-fixers and absolutely critical to most life (Introduction para. 1; Cyanophyta para. 8).They are present in aquatic environments both salty and fresh as well as terrestrial ones, from deserts to forests to parking lots.

A number of varieties of fresh-water cyanobacteria, however, pose health risks, especially in large quantities (Hoeger 639). These bacteria produce one of a number of toxic peptide molecules known collectively as cyanotoxins. Cyanotoxins are produced through genetically regulated biological pathways, and their prevalence in a wide variety of cyanobacteria species indicates both a very early common ancestor and a strong evolutionary relationship (Welker 552). Most of the data available surrounding these cyanotoxins relates microcystin, one of the classes that poses the greatest toxicity to humans (Welker 549). These molecules are produced by a wide number of species of cyanobacteria and attack the liver when absorbed, a defense mechanism originally intended to prevent grazing by fish species (Microcystins para. 1,2; Welker 552). They are produced and regulated by a section of the genome known as the mcy genes, and testing for the presence of these genes (labeled mcyA through mcyJ) has been strongly correlated with the presence of microcystins (Welker 549; Tanabe 633). These chemicals are especially dangerous in drinking water because they remain toxic even after drying and/or boiling (Stone slide 8).

This lab is involved in the analysis and characterization of microcystins and other correlated factors, including several varieties of the mcy gene cluster with geographic and climactic factors for a number of groups in the Northwest. Our research works to pave the way for better understanding of trends and movements of these concerning cyanobacteria throughout the waters of the Northwest.

Works Cited

Johnston, Bernadette R., and Jean M. Jacoby. "Cyanobacterial Toxicity and Migration in a Mesotropic Lake in Western Washington, USA." Hydrobiologia 495 (2003):79-91.

"Introduction to the Cyanobacteria." Museum of Paleontology. University of California. 28 Feb. 2009 <http://www.ucmp.berkeley.edu/bacteria/cyanointro.html>.

Webb, David T. "Cyanophyta." University of Hawaii at Manoa Botany. 28 Feb. 2009 <http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/Cyanobacteria.htm>.

Hoeger, S.J., Shaw, G., Hitzfeld, B.C. & Dietrich, D.R. (2004) Occurrence and elimination of cyanobacterial toxins in two Australian drinking water treatment plants. Toxicon, 43, 639-649.

Welker, Martin, and Hans von Döhren. "Cyanobacterial peptides – Nature's own combinatorial biosynthesis." FEMS Microbiology Reviews 30 (2006): 530-63.

"Microcystins." Cyanosite for Cyanobacteria, Blue-green Algae, and Prochlorophytes. 28 Feb. 2009 <http://www-cyanosite.bio.purdue.edu/cyanotox/toxins/microcystins.html>.

Tanabe, Yuuhiko, Kunimitsu Kaya, and Makoto M. Watanabe. "Evidence for Recombination in the Microcystin Synthetase (mcy) Genes of Toxic Cyanobacteria Microcystis spp." Journal of Molecular Evolution 58 (2004): 633-41.

Stone, David. "Cyanobacteria and their Toxins." Oregon Department of Human Services. 28 Feb. 2009 <http://oregon.gov/DHS/ph/envtox/docs/algaetoxins.pdf>.