Toxin production by Microcystis cultures isolated from Lake Erie
Start Date
23-5-2022 5:45 PM
End Date
23-5-2022 7:00 PM
Abstract
Harmful algal blooms dominated by Microcystis, a cyanobacterial genus, have significant public health and economic ramifications worldwide, including a $65 million economic impact from a single Lake Erie bloom. We isolated and sequenced 24 Microcystis cultures collected from Lake Erie between 2017-2019. Genomic data shows these cultures represent a breadth of known Microcystis diversity. Some cultures, isolated years apart, are genetically similar to each other (Average Nucleotide Identity >99%). The complete mcy operon, responsible for producing the hepatotoxin microcystin, was found in 6 cultures. A previously described partial mcy operon was identified in 2 cultures. The remaining 18 cultures lacked any mcy genes. Previous studies in Lake Erie highlighted intra-annual shifts from microcystin-producing to non-producing strains. Microcystin concentration, assessed using Enzyme-Linked Immunosorbent Assay (ELISA), supported genomic results with high concentrations (up to 900 μg L-1) in cultures with the full mcy operon and no or low toxin detected otherwise. Current work is determining how strains interact with co-occurring bacteria, how microcystin production and congeners vary with growth, and how these traits relate to their genetic properties. Overall, these results highlight phenotypic diversity among Microcystis strains and support a need for a nuanced understanding of microcystin production dynamics within ecosystems.
Toxin production by Microcystis cultures isolated from Lake Erie
Harmful algal blooms dominated by Microcystis, a cyanobacterial genus, have significant public health and economic ramifications worldwide, including a $65 million economic impact from a single Lake Erie bloom. We isolated and sequenced 24 Microcystis cultures collected from Lake Erie between 2017-2019. Genomic data shows these cultures represent a breadth of known Microcystis diversity. Some cultures, isolated years apart, are genetically similar to each other (Average Nucleotide Identity >99%). The complete mcy operon, responsible for producing the hepatotoxin microcystin, was found in 6 cultures. A previously described partial mcy operon was identified in 2 cultures. The remaining 18 cultures lacked any mcy genes. Previous studies in Lake Erie highlighted intra-annual shifts from microcystin-producing to non-producing strains. Microcystin concentration, assessed using Enzyme-Linked Immunosorbent Assay (ELISA), supported genomic results with high concentrations (up to 900 μg L-1) in cultures with the full mcy operon and no or low toxin detected otherwise. Current work is determining how strains interact with co-occurring bacteria, how microcystin production and congeners vary with growth, and how these traits relate to their genetic properties. Overall, these results highlight phenotypic diversity among Microcystis strains and support a need for a nuanced understanding of microcystin production dynamics within ecosystems.