Researchers are finding that organic acids and autolyzed yeast products are effective at reducing the impacts of pathogens in aquaculture production.
At Biomin, scientists continue to test and prove the efficacy of the company\'s enhanced organic acid Biotronic® Top3 on controlling bacterial disease outbreaks in aquaculture. They recently cultured a number of pathogens in growth medium, with and without the enhanced organic acid. The pathogens were chosen based on their ability to cause widespread disease and high economic losses in aquaculture, and included Aeromonas spp., Edwardsiella sp., Pseudomonas sp., Streptococcus sp., Vibrio spp. and Yersinia sp. Researchers observed that the organic acid effectively reduced the growth of all pathogens.
Biotronic® Top3 was most effective against Gram-negative pathogens, although inhibition of Streptococcus was also observed. This is not surprising, since the formulation contains a unique Biomin Permeabilizing Complex, specifically designed to weaken the outer membrane of Gram-negative bacteria.
A recent peer-reviewed publication demonstrated how Biotronic® Top3, an enhanced acidifier, can be used to reduce pathogens and improve disease resistance in aquaculture (Menanteau-Ledouble et al. 2017).
In one in vivo study, specific pathogen free (SPF) rainbow trout (Oncorhynchus mykiss) were split into two groups, and received either a commercial feed or the same feed supplemented with Biotronic® Top3. After 25 weeks, fish were artificially infected with Aeromonas salmonicida by intraperitoneal (IP) injection, immersion and cohabitation. For quality control purposes, fish in both treatments were also ‘mock’ infected to take into account background mortality. Once the infection had taken its course, the survival rate was calculated. In control tanks, mortalities were observed immediately indicating the virulence of the pathogen. In the Biotronic® Top3 treatments, much slower death rates were seen, indicating that the infection could be slowed down. This may benefit fish farmers as they can identify and treat diseases before incurring huge losses.
After 35 days of challenge, Biotronic® Top3 supplemented fish showed a considerably higher survival rate (80%), compared to just 60% in control tanks, indicating the protective capabilities of Biotronic® Top3. Furthermore, the rainbow trout that received Biotronic® Top3 had a significantly higher survival rate (70%) than those not receiving the supplement (25%) when challenged via IP injection.
