Production of bactericidal substances by a marine vibrio isolated from cultures of the scallop Argopecten purpuratus

A marine vibrio (strain C33) having inhibitory effects on the growth of the pathogen Vibrio anguillarum-VAR was isolated from seawater used in mass cu lture of the north-Chilean scallop Argopecten purpuratus. This bacterial is olate demonstrated broad inhibitory activity on several bacterial strains, including some pathogenic vibrios. Ethyl acetate extracts of extracellular products of strain C33 were separated by thin layer chromatography (TLC), a nd three fractions thus obtained were found to have antimicrobial activity when tested using microplate bioassays. One of the fractions (A2) having ma rked antimicrobial activity, was further purified using TLC and analyzed by IR spectrophotometry and NMR'H and was characterized on a preliminary basi s as an aliphatic hydroxyl ether. This compound demonstrated bacteriostatic activity against the important marine pathogens Vibrio parahaemolyticus an d V. splendidus, and as discussed in the paper, may be useful in developing natural strategies for the control of pathogens in mass cultures of Argope cten purpuratus and possibly other molluscs affected by these bacteria.