ß-N-methylamino-L-alanine (BMAA) is a neurotoxic amino acid that was originally isolated from the cycad tree, and was proposed as a possible cause of amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC) among the Chamorro people of Guam. Although this hypothesis was initially disputed, the discovery that BMAA is biomagnified within the Guam ecosystem coupled with the finding that it occurs in brain tissue of Chamorros who died of ALS/PDC generated a renewed interest in this molecule. Recently BMAA was found to be produced by symbiotic cyanobacteria of the genus Nostoc that are associated with the roots of cycad trees. Production of known cyanotoxins is generally considered to be phylogenetically unpredictable. In screening other species for this neurotoxin, we found that all five morphological groups of cyanobacteria possess BMAA. This finding suggests that BMAA production may be a primitive characteristic of the Cyanophyceae. Cellular concentrations of BMAA for some species approach 1% (by weight), suggesting that this molecule may function as a nitrogen storage product. The ubiquity of cyanobacteria in terrestrial, as well as freshwater, brackish, and marine environments, suggests a potential for widespread human exposure.
Presenter:
Dr. Robert Bidigare
Professor, University of Hawaii, Manoa
Director, Center for Marine Microbial Ecology & Diversity (CMMED)
Wednesday
January 10, 2007
2:00 p.m.
Pacific Ocean Science & Technology Building, POST 723
Refreshments will be served after the seminar in POST 121
The Pacific Research Center for Marine Biomedicine (PRCMB) is a newly established center at the University of Hawaii dedicated to trans-disciplinary research designed to gain new knowledge about the profound impacts of the ocean on human health. The Center is funded by the National Science Foundation and the National Institute of Environmental Health Sciences.
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