Nutrient Controls Over Cyanobacterial Synthesis of the Neurotoxin β-N-Methylamino-L-Alanine (BMAA) and Its Potential Accumulation in the Blue Crab (<i>Callinectes Sapidus</i>)

<p>Cyanobacteria are known to produce a variety of toxins that negatively impact both aquatic and terrestrial organisms. One putative neurotoxic compound is the non-protein amino acid β-N-methylamino-L-alanine (BMAA), which has epidemiological linkages to the development of several human neurological diseases. Three cyanobacterial species thought to produce BMAA —<em>Microcystis aeruginosa</em>, <em>Synechococcus bacillaris</em>, and <em>Nostoc sp</em>. —were grown in nutrient replete cultures to examine its synthesis and cellular distribution over a growth cycle. Production of BMAA was also examined in nutrient (nitrogen and phosphorus) deplete cultures of <em>Microcystis aeruginosa</em>. In addition, natural assemblages of phytoplankton dominated by cyanobacteria were collected from two Maryland Chesapeake Bay tributaries to determine whether natural cyanobacterial populations were producing BMAA. Blue crabs were also collected from the upper Maryland and lower Virginia Chesapeake Bay during the summer of 2018 to examine BMAA bioaccumulation in the stomach, hepatopancreas, and muscle tissues of these important benthic consumers. Concentrations of BMAA were determined via tandem high-performance liquid chromatography- mass spectrometry (HPLC-MS), a highly sensitive method that distinguishes between BMAA and analytically similar compounds, like the structurally related but non-toxic diaminobutyric acid (DAB). Although detection limits were between 25-106 pg wet weight for cyanobacteria and were 25 pg wet weight for blue crab tissues, BMAA was not found in any sample included in this study. Further research using similarly sensitive analytical methods are needed to determine the triggers for and variability of cyanobacterial BMAA production, and its potential transfer through the food web.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Ocean & Earth Sciences

Year dc:date.available

2019

Author dc:creator

• Hummel, Madeline M.

Contributors dc:contributor

• H. Rodger Harvey
• Margaret R. Mulholland
• Shannon L. Wells

• Nutrient controls
• Blue crab
• Cyanobacteria
• Chesapeake Bay
• Marine Biology
• Oceanography

Statement dc:rights

• <p>In Copyright. URI: <a href="http://rightsstatements.org/vocab/InC/1.0/">http://rightsstatements.org/vocab/InC/1.0/</a> This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).</p>

Identifier

9781088396797

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:oeas_etds-1093