Bacteriological Studies on Diseases of Cultured Laver-II

Bacteria associated with diseased laver

Abstract

In order to ascertain the bacterial role taken in the process of rotting or decaying of cultured laver, 24 strains of bacteria isolated from diseased frond of Porphyra yezoensis were studied and identified to the genus level. These bacteria were divided into phenons I, IIa, IIb, III and IV by numerical taxonomy, and were identified as species of the genera Cytophaga, Agarbacterium, Beneckea, Pseudomonas, and Vibrio respectively.
In vitro, three strains of Pseudomonas sp. and two strains of Vibrio sp. caused “green spot rotting”-like deterioration, and also five strains in the genera Beneckea and Agarbacterium caused the reddening of frond pieces. The other test strains did not show any noticeable changes in the test pieces of Porphyra frond.