Presence of ß-N-methylamino-L-alanine in cyanobacteria and aquatic organisms from waters of Northern Poland; BMAA toxicity studies

Abstract

BMAA (ß-N-methylamino-L-alanine) was originally found in the seeds of cycad Cycas micronesica in the 1960s. Some years later it was discovered that the amino acid is genuinely produced by endosymbiotic cyanobacteria. Further research has proven the neurotoxic activity of BMAA, leading to neurodegenerative disease diagnosed as amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC). The aim of the present work was to examine the occurrence of BMAA in samples from Polish waterbodies. Both, the field cyanobacterial samples and the isolated cyanobacterial strains were analyzed. Also mussel and fish samples were checked for the BMAA accumulation. The additional goal was to assess the biological activity of BMAA in in vivo and in vitro assays. In waters of Northern Poland, BMAA was detected in cyanobacteria from Synechococcales, Oscillatoriales and Nostocales orders. The free and protein-bound forms of BMAA were detected in 9 and 4 (of 37) environmental samples, respectively. Both forms of BMAA were also identified in 2 out of 21 cyanobacterial strains isolated from Polish waterbodies. Our analyses of cyanobacterial material did not confirm the presence of soluble protein-bound form of BMAA. The amino acid was detected neither in the tissues of fish nor in the mussels. Biological activity of BMAA was tested with the application of hippocampal neural cell line HT22 and crustaceans: Thamnocephalus platyurus, Artemia franciscana and Daphnia magna. Among them, only D. magna assay revealed toxic effects of BMAA. The results of our research did not demonstrate the widespread production of BMAA by cyanobacteria from Northern Poland waters.

Keywords: BMAA; Baltic Sea; Cyanobacteria; LC-MS/MS; Lakes of Pomerania Province.