Priestia aryabhattai was isolated from a continuous flow competitive exclusion culture (CFCEC) developed from the intestinal contents of adult Nile tilapia in Colombia and selected based on in vitro probiotic potential, with significant antibacterial activity against fish pathogens, acid pH resistance, and adherence capability. The whole genome was sequenced for species identification and functional annotation was carried out.
Also, in vivo effects of P. aryabhattai M10 feed supplementation were assessed in Nile tilapia. The probiotic bacteria were lyophilized with the feed (106 UFC ml-1), which was vacuum packaged and stored at 4°C until use.
Briefly, 114 tilapia fingerlings (1.05 g ± 0.08) were acclimated for two weeks and randomly assigned to the Control or P. aryabhattai treatment groups per triplicate. After four weeks, growth rate, feed conversion, and fish survival after a challenge with Streptococcus agalactiae were recorded.
After four weeks of administration to Nile tilapia alevins, P. aryabhattai significantly improved weight gain, specific growth rate, and feed conversion ratio in comparison to the control. Also, the survival of Nile tilapia alevins challenged with Streptococcus agalactiae was enhanced from 33.33% control to 73.33% with P. aryabhattai feed supplementation. To summarize, the research suggests that P. aryabhattai M10 is a promising new probiotic option for enhancing the growth performance and survivability of Nile tilapia alevins.
Funding:
Doctoral Fellowship 727-2015 Doctorados Nacionales Colciencias and Project code123080863753, call 808, Evaluation of the probiotic potential of a competitive exclusion culture from tilapia(Oreochromis niloticus) intestinal microbiota. Patrimonio Autonomo Fondo Nacional De Financiamiento Para La Ciencia, La Tecnología y La Innovación Francisco José De Caldas.