Probiotic properties of Brevibacillus brevis and its influence on sea bass (Dicentrarchus labrax) larval rearing

Abstract

Efficacy of Brevibacillus brevis strain and its influence on larval rearing of sea bass (Dicentrarchus labrax) were investigated in the present work. Biochemical analyses permit to identify this strain as B. brevis. This bacterium has an inhibitory effect against fish pathogenic bacteria, especially the genus of Vibrio. Enzymatic characterization revealed that B. brevis was lipase positive, amylase, lecithinase and caseinase negative. Adherence assays to abiotic surfaces and challenge test with Artemia larvae demonstrate that B. brevis was fairly adherent and play an important role in the enhancement of the protection of Artemia culture against pathogens. Treatment of sea bass larvae with B. brevis not affects survival compared to control group. Specific growth and linear rate of sea bass larvae feed by Artemia enriched with potential probiont was improved compared to the control treatment. Therefore, this investigation suggested that the tested strain can be considered as promising potential probiotic that can be used incorporated in Artemia nauplii for rearing of fish and selfish larvae based on the enhancement of survival and growth rate and pathogens elimination of in vivo and in vitro conditions. Key words: Brevibacillus brevis, probiotics, antagonism, adhesion, Artemia, Sea bass larvae, aquaculture.