Characterization of probiotic properties of lactic acid bacteria isolated from an estuarine environment for application in rainbow trout (Oncorhynchus mykiss, Walbaum) farming.

Bacterial attachment to fish surfaces and the capacity to compete with pathogens for adhesion sites are essential characteristics in order to select a candidate probiotic for aquaculture. Twelve lactic acid bacteria (LAB) isolated from fish and sediments from Bahía Blanca Estuary, Argentina, were examined for in vitro adhesion to rainbow trout mucus, cell surface properties and competitive exclusion against two salmonid pathogens, Yersinia ruckeri and Aeromonas salmonicida. In order to assess their survival through the digestive tract, pH and rainbow trout bile tolerance were evaluated.