Development of probiotic preparation based on autochthonous lactobacilli for salmonids intended to improve fish health and production of quality food

The project is focused on the development and study of probiotic preparation based on autochthonous probiotic lactobacilli, which will be designed to increase the resistance of salmonids to diseases and stress without the use of antibiotics, which will improve the quality and safety of the final food. Probiotic strains of lactic acid bacteria were obtained in our previous research directly from healthy trouts and were tested and selected in vitro in accordance with EFSA recommendations, taking into account the specifics of the aquatic environment. For their application to commercial pelleted feed, a new, low-cost microencapsulation technology which protects bacteria against environmental influences will be used. The thus prepared feed will be tested for the stability and survival of the bacteria in different storage conditions. Subsequently, clinical trials in the approved fish facilities will be performed in order to monitor the ability of bacteria to colonize the intestinal apparatus of rainbow trout and their impact on microbiocenosis and morphology of gut, immune response, and production parameters including also fish meat quality parameters monitoring. Similarly, an infectious experiment will be conducted to assess the ability of a probiotic product to attenuate the course of infection with Aeromonas salmonicida, which is one of the most important bacterial pathogens of salmonids. Received results contribute to the expansion of knowledge in research of factors and mechanisms such probiotics or pathogen control and influence intestinal microbiocenosis and morphology, and immune response of the fish. The results will be applicable to the subsequent development of a new probiotic preparation for salmonid fish designed to increase the immunity of the organism and to improve production parameters without the use of antibiotics, through the optimization of intestinal microbiocenosis and immunomodulation. The final result will be the production of quality and safe fish meat and reduction of environmental burden.