Effect of Bacillus firmus C101 on the growth of Litopenaeus vannamei Boone (White Shrimp) post-larvae, and Brachionus plicatilis s.s. Muller (Rotifer)

The growing demand for aquaculture protein suggests seeking biotechnological alternatives that improve the cultivation of species of commercial interest. In this study, Bacillus firmus C101 was evaluated as a growth promoter and probiotic potential, which was characterized and subsequently administered (106 CFU mL-1* day) in post-larvae of white shrimp (Litopenaeus vannamei) and rotifers (Brachionus plicatilis sensu stricto). B. firmus C101 was observed to have the tolerance to bile salts, strong phosphatase activity, and antimicrobial activity against pathogens such as Vibrio alginolyticus and Aeromonas hydrophila, among others. On the other hand, after its administration for three weeks to postlarvae of shrimp, it caused a significant increase (p < 0.05) in the specific growth rate (TEC = 3.8 ± 0.7 % day-1), the increase in daily weight (ADG = 1.5 +- 0.1 mg day-1) and in the feed conversion rate (TCA = 1.5 ± 0.1 %) compared to controls without the addition of this bacterium (sterile PBS). Likewise, the administration of B. firmus C101 (106 CFU mL-1 * day) to rotifers caused an increase in the population growth rate (TC = 20.2 ± 1.5 % day-1), fertility (F = 0.4 ± 0.03 eggs individuals-1) and productivity (R = 16.0 ± 0.7 individuals mL-1 * day) after 48 h of culture. Based on the above and in comparison with other studies, B. firmus C101 is suggested as a potential probiotic and growth promoter in shrimp postlarvae, and as the first report of the effect of its administration in rotifers. However, studies on the possible mechanisms of action are required, as well as tests on a pilot and commercial scale to validate these results and their possible transfer to the productive sector.