Transfer of a cyanobacterial neurotoxin within a temperate aquatic ecosystem suggests pathways for human exposure.

Abstract

beta-methylamino-L-alanine (BMAA), a neurotoxic nonprotein amino acid produced by most cyanobacteria, has been proposed to be the causative agent of devastating neurodegenerative diseases on the island of Guam in the Pacific Ocean. Because cyanobacteria are widespread globally, we hypothesized that BMAA might occur and bioaccumulate in other ecosystems. Here we demonstrate, based on a recently developed extraction and HPLC-MS/MS method and long-term monitoring of BMAA in cyanobacterial populations of a temperate aquatic ecosystem (Baltic Sea, 2007-2008), that BMAA is biosynthesized by cyanobacterial genera dominating the massive surface blooms of this water body. BMAA also was found at higher concentrations in organisms of higher trophic levels that directly or indirectly feed on cyanobacteria, such as zooplankton and various vertebrates (fish) and invertebrates (mussels, oysters). Pelagic and benthic fish species used for human consumption were included. The highest BMAA levels were detected in the muscle and brain of bottom-dwelling fishes. The discovery of regular biosynthesis of the neurotoxin BMAA in a large temperate aquatic ecosystem combined with its possible transfer and bioaccumulation within major food webs, some ending in human consumption, is alarming and requires attention.

• Authors: Sara Jonasson, Johan Eriksson, Lotta Berntzon, Zdenek Spácil, Leopold L Ilag, Lars-Olof Ronnevi, Ulla Rasmussen, Birgitta Bergman
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 107 Issue 20 Pg. 9252-7 (May 18 2010) ISSN: 1091-6490 [Electronic] United States
• PMID: 20439734 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Amino Acids, Diamino
• Cyanobacteria Toxins
• Marine Toxins
• Neurotoxins
• beta-N-methylamino-L-alanine

Topics

• Amino Acids, Diamino (biosynthesis, metabolism, pharmacokinetics)
• Animals
• Chromatography, High Pressure Liquid
• Cyanobacteria (chemistry)
• Cyanobacteria Toxins
• Environmental Exposure
• Fishes (metabolism)
• Food Chain
• Humans
• Invertebrates (chemistry)
• Marine Toxins (biosynthesis, metabolism, pharmacokinetics)
• Neurotoxins (biosynthesis, metabolism, pharmacokinetics)
• North Sea
• Sweden
• Tandem Mass Spectrometry
• Zooplankton (chemistry)