Probiotic properties of Bacillus strains isolated from the gastrointestinal tract against pathogenic Vibriosis

Vibriosis is one of the major diseases leading to massive fish mortality. Probiotics may provide a potential alternative method protect from pathogens and promote balanced environment minimizing use antibiotics chemotherapy. The aims this study were (i) isolate purify marine spore-former strains Sardine shrimp intestine, (ii) screen for bacteria with probiotic properties, (iii) carry out their in vitro safety assessment using subtractive procedure. Among 108 strains, five exhibited strong antibacterial activity against such as Vibrio harveyi anguillarum . These selected unaffected by high-temperature gastrointestinal conditions; produced amylase, protease, lipase activities; showed high percentages auto-aggregation co-aggregation pathogens, well adhesion mucus. Partial 16S rDNA gene sequencing MALDI-TOF MS revealed that isolates are Bacillus amyloliquefaciens or subtilis All them susceptible antibiotics, while hydrolic enzymes virulence factors not detected B. S17. In conclusion, based on proprieties assessment, S17 could serve candidate aquaculture.