Oxygen and sulfide dynamics in a horizontally migrating cyanobacterial mat: Black band disease of corals

Abstract

Black band disease is caused by a horizontally migrating microbial consortium which overgrows and kills reef‐building corals in many areas of the world. The cyanobacterium Phormidium corallyticum, the sulfide‐oxidizing bacterium Beggiatoa sp., fungi, and sulfate‐reducing bacteria dominate the consortium, which is generally several mm to 1 cm in width and ca. 1 mm in thickness. Microelectrode measurements revealed photosynthetically produced O2‐supersaturation in upper layers during day, although conditions at the band‐coral interface were consistently anoxic and, at night, sulfide‐rich. Diel distributions of oxygen and sulfide resembled those from cyanobacterial mats in sulfur springs, intertidal mats and hypersaline lagoons.

Unraveling the microbial processes of black band disease in corals through integrated genomics

“…2c). This greater expression of anaerobic metabolism in BBD lesions is likely linked to the presence of anoxic microenvironmental conditions formed within the BBD lesion41, and therefore indicates another factor contributing to the virulence of BBD1542 since microbially-mediated anoxia and consequent decrease of pH can rapidly initiate degradation of coral tissues43.…”

First Record of Black Band Disease in the Hawaiian Archipelago: Response, Outbreak Status, Virulence, and a Method of Treatment

“…Motile, white filamentous bacteria from Kaua‘i BBD lesions were morphologically similar to other strains of Beggiatoa [46], and corresponding 16S rRNA gene sequences were identified as Beggiatoa . Prior studies on BBD have exclusively used the distinct morphology of Beggiatoa to identify this bacterium [24, 25]. Our study is the first to use morphology, behavior and molecular analysis for identification.…”

“…), sulfate-reducing bacteria that include members of the Desulfovibrio genus, and numerous heterotrophic bacteria [21–23]. The cyanobacteria and sulfide-oxidizing bacteria exhibit vertical migration within the microbial mat under changing diel light conditions, which results in dynamic vertical microgradients in oxygen and sulfide [24, 25]. The sulfate-reducing bacteria are responsible for the highly concentrated sulfide and anoxic conditions underneath the BBD mat that is lethal to coral tissue [25, 26].…”

A Novel Investigation of a Blister-Like Syndrome in Aquarium Echinopora lamellosa

“…Histological analysis showed the epidermis of blister-affected samples was found to be similar to that of healthy samples, with the corals Symbiodinium, appearing to remain intact and blistered tissues showing no signs of necrosis. Given that acridine orange only appeared to show autofluorescence of coral, zooxanthellae and coral mucus, there were no microbial associates present within the blistered tissues, highlighting that in contrast to many other coral diseases [2]–[8], [10], [13]–[17], [27], [58], [59], this syndrome is unlikely caused by microbial pathogens. Instead, all blistered sections exhibited growth anomalies of the coral tissue (GAs) that appeared morphologically similar to the mucocyte layer of the epidermis.…”

“…These diseases include: coral bleaching, white plagues, white syndromes, yellow band diseases, black band disease, coral ciliate infections, fungal infections and growth anomalies. Most commonly, coral diseases are attributed to bacterial pathogens, such as cyanobacteria in Black Band Disease [2]–[5] and a Vibrio consortium in Yellow Band Disease [6], [7]. Other pathogenic agents in corals receive considerably less attention but include ciliates, associated with Brown Band Disease [8], [9], White Syndrome [8], Skeletal Eroding Band [10], [11]and the Caribbean Ciliate Infection [12], and fungal pathogens associated with Dark Spot Syndrome [13] and Aspergillosis in gorgonian sea fans [14]–[17].…”