Analysis of different protocols for commercial probiotic multiplication in aquaculture systems
The use of commercial probiotics in aquaculture as an alternative to antibiotics has shown viability and positive results. Probiotics can be defined as non-pathogenic living organisms, used with the objective of improving the health of the host, such as bacteria and yeasts that are capable of colonizing the gastrointestinal tract of cultured animals, as well as acting in the culture environment against the development of pathogens . Some empirical strategies are used in Shrimp Farms in an attempt to multiply bacteria from commercial probiotics in an artisanal way, aiming to reduce costs with the purchase of the commercial product. The hypothesis that commercial probiotics can be multiplied was tested in this Dissertation. The present study was carried out at the Marine Aquaculture Station, IO - FURG and had three experiments, carrying out home protocols for the multiplication of a commercial probiotic used on farms in Brazil, Peru and Ecuador. Each experiment lasted 24 hours. Water quality parameters were monitored and water collections were carried out at 00h and 24h to quantify bacteria and protozoa. Experiment I: 25g of Pro-W probiotic, 25g of powdered milk, 50ml of molasses and 25g of calcium carbonate; Experiment II: 25g of Pro-W probiotic, 50g of rice bran, 33.33g of crystal sugar and 12.5g of sodium bicarbonate. Experiment III: 25g of Pro-W probiotic, 25g of Bokashi Bran, 50ml of molasses and 12.5g of sodium bicarbonate. Experimental units with 25L useful volume were used and the protocols used were based on the practice of farms in Brazil, Peru and Ecuador. Each experiment had 6 treatments and 3 repetitions each. The treatments were carried out in fresh water (0.31 ± 0.06 g/L-1) and in marine water (25.06 ± 0.44 g/L-1). T1: Control in fresh water; T2: Control in marine water; T3: Negative control in fresh water; T4: Negative control in seawater; T5: Freshwater protocol; T6: Marine water protocol. The three experiments showed growth of Bacillus morphotype, coccoid and filamentous bacteria in all treatments. There was no effect of the treatments on the final growth of bacteria and protozoa. These results indicate that the protocols used do not contribute to the specific growth of Bacillus-type bacteria, similar to commercial probiotics.