Isolation of antagonistic bacteria associated with the stony coral Montipora digitata in Okinawa, Japan

抄録

Coral “holobiont” is defined as a complex as-semblage which is comprised of the coral animal and its associated microorganisms. These organisms (including bacteria, archaea, cyanobacteria, fungi and also virus) inhabit coral tissues, coral skeleton, and the coral surface forming the so-called surface mucus layer (SML). The SML bears a diverse assemblage of antagonistic bacteria which suppress overgrowth of other microorganisms and maintain the healthy status of coral holobiont. On the basis of this background, we accomplished the isolation of antagonistic bacteria associated with Montipora digitata colonies sampled at Sesoko Island, Okinawa, Japan. As a result, 13 strains of antagonistic bacteria were isolated and identified by the analysis of partial 16S rDNA sequences. The bacteria were identified to belong to either the genus Pseudoalteromonas, Vibrio, or Staphylococcus. We attempted isolation of antifungal compounds from newly isolated Pseudoalteromonas sp. S10. By analysis of NMR and ESI-MS spectral data, the antifungal com-pounds were identified as known macrolactams alter-amides A and B.