INHIBITORY EFFECT OF BACTERIAL UBIQUINONES ON THE SETTLING OF BARNACLE, BALANUS AMPHITRITE

In an attempt to clarify the influence of marine bacteria on the settl ing of fouling invertebrate larvae, we screened for inhibitors, produc ed by marine bacteria, of settling by cyprids of the barnacle, Balanus amphitrite. We found that the culture broth of Alteromonas sp. strain number KK10304, which was associated with the marine sponge, Halichon dria okadai, effectively inhibited settling of the cyprids. Bioassay-g uided isolation indicated ubiquinone-8 (1) as an effective inhibitor o f cyprid settling. As ubiquinones are widely distributed in bacteria, several related compounds were also tested.