Lactic acid bacteria metabolites in fish feed additives inhibit potential aquatic and food safety pathogens growth, and improve feed conversion

The fermented broth of lactic acid bacteria (LFB)was the side product while lactic acid bacteria produced; however, it was abundant of antimicrobial activity. That might be a good candidate for feed additive in aquaculture. In this study, the fermented broth of Lactobacillus paracasei GL-156, the most antibacterial activity, was further evaluated the safety, growth performance gut microbiota. Common carp consumed the feed in dose of 1000 ppm LFB, the survival was no significant different with control group, but the growth performance was significant increased. In the intestine microbiota analysis, the treatment fish shown the decrease of vibrio, but no different of total bacterial count. These results demonstrate the LFB from GL-156 in enhancing the growth performance, inhibiting the growth of pathogenic bacteria, and promoting the growth of probiotic organisms. Compare with live probiotics currently used in aquaculture, using LFB will achieved beneficial effects equally, while providing superior tolerance to manufacturing processes, and in the lower cost.