Isolation of Pseudoalteromonas elyakovii strains from spot-wounded fronds of Laminaria japonica

Spot-disease of Laminaria fronds has been occasionally observed in coastal areas of Hokkaido Japan. A huge outbreak of the disease occurred in Laminar ia japonica near the southeastern part of Hokkaido in 1998. Three bacterial strains showing Laminaria-frond degrading activity were isolated from the spot-wounded fronds of L. japonica collected at Minamikayabe, Hokkaido, Jap an. All the strains were tentatively identified as Alteromonas strain, and two of them were identified as Pseudoalteromonas elyakovii, of which the sp ecies included an alginolytic marine bacterium isolated from a spot-disease of Laminaria japonica var, ochotensis occurring at Rishiri Island at 1985. The phenotypic and genotypic characterizations of the Laminaria-frond degr ading bacteria were described.