title: Detection of the neurotoxin BMAA within cyanobacteria isolated from freshwater in China.
abstract: The cyanobacterial neurotoxin, beta-N-methylamino-l-alanine (BMAA), has been suggested as an important environmental factor for neurodegenerative disease such as amyotrophic lateral sclerosis- Parkinsonism dementia complex (ALS/PDC) in Guam. BMAA was detected within the majority of cyanobacterial isolates surveyed in both free and symbiotic cyanobacteria, living in freshwater as well as marine environments. In this study, we report two methods using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS) each coupled with a different type of hydrophilic interaction liquid chromatography (HILIC) column to detect BMAA. A third method using AQC-derivatized BMAA was also used for comparison. Axenic cultures of Microcystis aeruginosa and Nostoc sp. isolated from Chinese freshwater were analyzed for both free and protein-bound BMAA at the exponential growth stage. Cultures of two strains of M. aeruginosa collected at four growth stages were also analyzed for the presence of BMAA. BMAA was detected in the Nostoc sp. at very low concentrations (<0.07pmoles on column) only when precolumn AQC derivatization was used. No BMAA was detected in the Chinese derived axenic cultures of Microcystis; detection limits for the LC-ESI-MS and LC-ESI-MS/MS without precolumn derivatization were 10ng and 2pg BMAA on column, respectively. We suggest that cyanobacteria grown under some culture conditions may be relatively free of BMAA.
authors.affiliation: Key Laboratory of Marine Environmental Sciences and Ecology, Ocean University of China, Qingdao 266100, PR China.
authors.forename: Aifeng
authors.initials: A
authors.lastname: Li
authors.forename: Zhijia
authors.initials: Z
authors.lastname: Tian
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Rencheng
authors.initials: R
authors.lastname: Yu
authors.forename: Sandra Anne
authors.initials: SA
authors.lastname: Banack
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000599:Amino Acids, Diamino / Q000032:analysis / Q000378:metabolism*; D001427:Bacterial Toxins / Q000032:analysis / Q000378:metabolism*; D002681:China; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000737:chemistry / Q000378:metabolism*; D000087522:Cyanobacteria Toxins; D004784:Environmental Monitoring; D018690:Excitatory Amino Acid Agonists / Q000032:analysis / Q000378:metabolism*; D005618:Fresh Water / Q000737:chemistry*; D008387:Marine Toxins / Q000032:analysis / Q000378:metabolism*; D052998:Microcystins / Q000032:analysis / Q000378:metabolism*; D009498:Neurotoxins / Q000032:analysis / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D000599:Amino Acids, Diamino; D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D018690:Excitatory Amino Acid Agonists; D008387:Marine Toxins; D052998:Microcystins; D009498:Neurotoxins; D014874:Water Pollutants, Chemical; C001824:beta-N-methylamino-L-alanine