Probiotic System for Bivalve Shellfish Aquaculture

There has been increasing interest in the use of beneficial bacteria (probiotic bacteria) to exclude bacterial pathogens in the intensive aquaculture of bivalve mollusk seed, shrimp postlarvae, and larval fish. As our work and that of others have shown, marine bacterial strains with probiotic activity are not uncommon. However, a validated method for the biologically effective and cost effective method of producing, introducing and maintaining the probiotic bacteria in bivalve shellfish systems is required. The primary subject of this proposal is to test the addition of promising probiotic bacterial candidates (presently archived in the laboratory), grown as monocultures, to larval and juvenile oyster cultures and evaluate their ability to protect the shellfish from challenge by bacteria pathogens. Promising candidates will be characterized for optimal concentration and frequency of addition in order to establish a recoverable and biologically protective concentration of probiotic candidates. Phase I studies will be conducted in laboratory microcosm cultures followed by scale up to commercial size cultures in Phases 2 and 3. There will be a limited evaluation of compatibility of probiotic bacteria with algal cultures and evaluation of any potential for resistance development of pathogens to probiotics.