In vivo efficiency of Bacillus sp. isolated from biofloc system on growth, haematological, immunological and antioxidant status of genetically improved farmed tilapia (GIFT)

Abstract

In aquaculture, Biofloc technology is emerging as one of the successful sustainable technologies to increase production. It is known to possess several immunostimulatory compounds exhibiting possible probiotic effect in culture. Here, we explored the<em> in vivo</em> efficiency of <em>Bacillus infantis </em>(T1), <em>B. subtilis</em> (T2), <em>Exiguobacterium profundum</em> (T3) and <em>B. megaterium</em> (T4) isolated from biofloc systems for improving the growth and immune performance of genetically improved farmed tilapia (GIFT). Animals (10<u>+</u>0.08 g) were stocked at a density of 100 per m^-3 in 500 L FRP tanks for 42 days in triplicate. All the four probiotics (OD =1) were mixed with basal diet in treatments and feed without probiotic maintained as control. A significant difference (<em>P</em> <u><</u>0.05) in weight gain, specific growth rate and FCR were observed between treatments and control with 100% survival. Serum albumin, globulin, protein, total blood count, glucose, myeloperoxidase activity and SOD were significantly different (<em>P</em> <0.05) between treatments and control. T4 and T2 showed better immunological and anti-oxidant ability when compared to other strains. Results from principal component analysis demonstrated that <em>B. megaterium </em>and <em>B. subtilis</em> can be the promising probiotic bacteria isolated from biofloc systems exhibiting multiple benefits with improved growth and health of the culture animals.