Study on Bacillus Isolated from Intestine of Persian Sturgeon (<i>Acipenser persicus</i>) Comparing with Commercial Probiotics

Abstract

At present, probiotic bacteria are proposed as an important alternative for antibiotic elimination and for providing renewable products through biological control in cultivation systems of marine fish larvae. The aim of this study is to compare the effects of native and commercial probiotics on growth parameters of Persian sturgeon (Acipenser persicus) larvae fed with controlled biomar diet. Experimental diets with three probiotic bacterial mixture including commercial lactobacillus (L. plantarum and L. rhamnosus), commercial Bacillus (B. subtillis and B. licheniformis) and Bacillus isolated from intestine of Persian sturgeon (B. mycoides) were completed in two levels (6.1 and 7.2 log CFU in each g of feed) and were fed to larvae of Persian sturgeon in six experimental treatments. The control treatment was fed with diet without supplementation. The experiment was done in randomized design. In all the treatments, feed conversion index was increased considerably and had significant difference with control treatment and in all the experimental treatments influenced by probiotics were higher than that of control treatment (P<0.05). The highest rate means of special growth (1.84±0.21%) and thermal growth index (3.44±0.37%) was obtained respectively in treatment C1 and C2 (isolated from intestine). Maximum special growth rate (SGR %) were obtained from C1 (4.69±0.71%) and B2 (4.62±0.87%, commercial Bacillus). In addition, native probiotic bacteria had better performance than the non native commercial species as well as selection of suitable probiotic (natural) with respect to fish species, region and condition of culture plays a special importance role in enhancing the yield of Persian sturgeon larvae.