Abstract
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. All LAB strains survived for 1.5h incubation in 10% rainbow trout bile. Most of the strains survived 1.5h at pH 3.0 and three of them showed a reduction of viable counts lower than 2 logarithms, with respect to control (pH 6.5). Only a few strains showed tolerate pH 2.0. All the strains were able to attach to rainbow trout skin mucus (10(4)-10(6)cells/cm(2)), to glass (10(4)-10(5)cells/cm(2)) and to stainless steel (10(3)-10(4)cells/cm(2)). Sixty percent of LAB strains were capable of competing with and successfully excluding Y. ruckeri and all strains were able to displace it. Against A. salmonicida, 75% of LAB strains competed successfully, 50% were capable of displacing and 60% excluded this pathogen. Our data suggest the potential of these strains as anti-infective agents for use in rainbow trout culture. This study is the first report on the probiotic potential of LAB strains isolated from an estuarine environment from Argentina.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
