Application of Bacillus amyloliquefaciens at scale of Pangasius breeding

Studying and evaluating the effect of Bacillus amyloliquefaciens strain on the quality of Pangasius breeding.
Pangasius breeds.
Pangasius is one of the key export items of Vietnam's aquaculture industry. However, in recent years, Pangasius production and consumption are facing a number of difficulties such as rising raw material prices, raw fish prices are low and consumer markets are not stable, In parallel with that, the long-term epidemic situation is still an unsolved problem of the farming areas. Most farming areas have common diseases in catfish, especially liver and kidney disease caused by Edwardsiella ictaluri and hemorrhagic disease caused by Aeromonas hydrophila.
Currently, the application of beneficial microorganisms to control the growth of pathogenic bacteria, increase fish resistance and treat the environment is one of the preventive measures being considered.
Probiotic bacteria have the ability to produce many different types of bacteriocin (in the form of small peptides or large proteins), or antibacterial compounds to inhibit pathogens or other competitors. In addition, some probiotic strains can secrete organic acids and volatile fatty acids (e.g., lactic acid, butyric acid, propopionic acid) which reduce the intestinal pH, thereby preventing pathogens. opportunity. When adding probiotic bacteria to the pond, the health of aquatic animals will be improved through the elimination of pathogens or at least minimizing the impact of pathogens by improving amount of water (Moriarty et al., 1998). Studies have also demonstrated that the addition of beneficial bacteria to pond water also helps increase the growth performance and improve the immune system of aquatic animals (Wang et al., 2000; Rao et al., 2007).
In addition, previous studies also showed that the addition of beneficial microorganisms during the fry phase (larvae) to aquatic animals has a digestive aid as they support the overall biosynthesis process. combination of extracellular enzymes (protease, amylase, lipase) as well as provide growth factors (vitamins, fatty acids and amino acids) thus helping nutrients to be absorbed more effectively (El-Haroun et al. ., 2006). Some probiotic bacteria such as B. toyoi, B. subtilis, L. acidophilus, L. bugaricus, ... will help increase feed efficiency, stimulate growth, and increase fish survival rate (Enyidi and Onuoha , 2016). Therefore, in this study, the ability to apply B. amyloliquefaciens strain in pangasius hatchery production was surveyed in farming households in An Giang province. This is an important evaluation step for developing B.
amyloliquefaciens prevent disease.
Strains B. amyloliquefaciens have the following advantages: no harm to humans and hosts; strong antagonistic to E. ictalrui (the causative agent of pus in liver and kidney) and A. hydrophila (the causative agent of hemorrhage); inhibit the growth of E. ictaluri in culture medium; can grow and develop as well as maintain antagonism under extreme conditions (pH 5-9, NaCl 1-6%, bile salts 2%) and secrete extracellular enzymes (amylase, cellulase, protease) (Le Luu Phuong Hanh et al., 2015).
A trial to evaluate the effectiveness of using B. amyloliquefaciens strain was conducted on a field scale at Pangasius farming households in Thoai Son district, An Giang province. This trial was conducted in 2 batches, each lasting for 2 months, with 2 treatments: the experimental treatment (using B. amyloliquefaciens strains) and the control treatment (not using B. amyloliquefaciens strains).
The size of Pangasius used in the experiment was newly fry.
B. amyloliquefaciens suspension was mixed with 20 L of pond water and splashed all over the pond surface before stocking 24h powder. The addition of B. amyloliquefaciens to the pond is conducted periodically once a week, for the next 2 weeks.
After 40 days of culture, the quality of pangasius and pond water improved, the survival rate of the fish in the experimental treatment was 28.8%, the fish size was 160 fish / kg. While in the control pond, it was 7.2%, fish size 150 fish / kg. The weight and average size of the experimental fish were 1.45 ± 0.52g and 53.27 ± 7.1mm, respectively, increasing 12.40% and 5.55% compared to the control group (1.29 ± 1,18g; 50,53 ± 11,16mm).
The pond water environment is suitable for zooplankton growth and development, ensuring a natural food source for Pangasius to use. During the nursery process, farmers hardly use any additional biological products to improve water quality.
In general, the results obtained prove that strain B. amyloliquefaciens is effective in improving Pangasius quality, increasing fish resistance and raising pond environment quality when used at scale. field. These are important databases for the development of probiotics to prevent pus and liver disease for Pangasius with B. amyloliquefaciens strain.
Updated on 23-12-2019
According to Tepbac