title: The presence of the cyanobacterial toxin microcystin in black band disease of corals.
abstract: Black band disease (BBD) is a migrating, cyanobacterial dominated, sulfide-rich microbial mat that moves across coral colonies lysing coral tissue. While it is known that BBD sulfate-reducing bacteria contribute to BBD pathogenicity by production of sulfide, additional mechanisms of toxicity may be involved. Using HPLC/MS, the cyanotoxin microcystin was detected in 22 field samples of BBD collected from five coral species on nine reefs of the wider Caribbean (Florida Keys and Bahamas). Two cyanobacterial cultures isolated from BBD, Geitlerinema and Leptolyngbya sp. contained microcystin based on HPLC/MS, with toxic activity confirmed using the protein phosphatase inhibition assay. The gene mcyA from the microcystin synthesis complex was detected in two field samples and from both BBD cyanobacterial cultures. Microcystin was not detected in six BBD samples from a different area of the Caribbean (St Croix, USVI) and the Philippines, suggesting regional specificity for BBD microcystin. This is the first report of the presence of microcystin in a coral disease.
authors.affiliation: Department of Biological Sciences, Florida International University, Miami, FL 33612, USA. laurie.richardson@fiu.edu
authors.forename: Laurie L
authors.initials: LL
authors.lastname: Richardson
authors.forename: Raju
authors.initials: R
authors.lastname: Sekar
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Myers
authors.forename: Miroslav
authors.initials: M
authors.lastname: Gantar
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Voss
authors.forename: Longin
authors.initials: L
authors.lastname: Kaczmarsky
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Remily
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Boyer
authors.forename: Paul V
authors.initials: PV
authors.lastname: Zimba
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry* / Q000382:microbiology*; D017691:Caribbean Region; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005798:Genes, Bacterial; D013058:Mass Spectrometry; D052998:Microcystins / Q000032:analysis* / Q000235:genetics / Q000633:toxicity; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000187:drug effects; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D052998:Microcystins; C078588:microcystin; D010749:Phosphoprotein Phosphatases