The main role of various probiotics in aquaculture
The use of probiotics is one of the important technical means to implement healthy aquaculture. Micro-ecological preparations are also called micro-ecological mediators, prebiotics, probiotics, probiotics, and mycosins. Under the guidance of micro-ecological theory, they use beneficial microorganisms isolated from farmed animals or their living environments. A living bacteria preparation made by a special process. It has the characteristics of no toxic side effects, no pollution, no residue, and low cost. It can inhibit the growth of pathogenic microorganisms, improve the immunity of the breeding objects themselves, and maintain the ecological balance of breeding.
【Types of probiotics】
According to the purpose, microecological preparations can be divided into two categories: one is the internal microecological improver, which is added to the feed to improve the composition of the microbial community in the breeding object, and the most widely used are lactic acid bacteria, bacillus, and yeast , EM bacteria, etc., such as Yifuyuan aquatic animal growth promoter; the other is water quality micro-ecological improver, which is put into the aquaculture water environment to improve the substrate or water quality, mainly including photosynthetic bacteria, bacillus, nitrifying bacteria, Denitrifying bacteria, EM bacteria, etc., such as Yifuyuan special bacteria liquid for aquatic products.
Photosynthetic bacteria are a group of bacteria that can carry out photosynthesis. Its cells are rich in protein, multivitamins, biotin, carotenoids, coenzyme Q and other physiologically active substances. The bacteria can absorb harmful substances such as ammonia nitrogen, nitroso nitrogen, hydrogen sulfide and organic acids in the water body, and inhibit the growth of pathogenic bacteria.
Bacillus is a gram-positive bacterium and is a ubiquitous class of aerobic bacteria. The bacteria can exist in the intestinal tract of aquatic animals in the form of endospores and secrete highly active protease, lipase, and amylase, which can effectively improve the utilization rate of feed and promote the growth of aquatic animals; it can also eliminate or reduce pathogenic bacteria. Bacillus can also decompose and absorb protein, starch, fat and other organic matter in water and sediment to improve water quality and sediment.
Nitrifying bacteria are the collective name of nitrosifying bacteria and nitrifying bacteria, which belong to the category of self-supporting bacteria. Nitrosifying bacteria convert ammonia nitrogen in water into nitrite nitrogen, and nitrifying bacteria can oxidize nitrite into nitrate nitrogen that is harmless to aquatic animals. Nitrifying bacteria are mainly made into compound microecological preparations together with other bacteria.
Denitrifying bacteria are composed of microbial populations with denitrification, mainly converting nitrate or nitrite into nitrogen and releasing it, and are mostly used to treat sediment. Under the condition that the dissolved oxygen at the bottom of the culture pond is lower than 0.5 mg/L and the pH value is 8-9, the denitrifying bacteria can use the sediment in the organic matter as a carbon source, and convert the nitrate in the sediment into harmless nitrogen gas. into the atmosphere. The denitrification process can consume a large amount of fermentation products and organic matter deposited at the bottom of the pond, so that the content of organic matter and nitrate in the bottom sludge can be rapidly reduced, effectively preventing drastic changes in water quality caused by climate change.
Lactic acid bacteria are bacteria that can ferment sugars to produce lactic acid, which can inhibit the activities of harmful microorganisms, the proliferation of pathogenic bacteria, and the corruption of organic matter. Lactic acid bacteria can decompose lignin and cellulose, which are difficult to decompose at normal temperature, and ferment organic matter into effective nutrients for animals and plants.
Yeast is a group of single-celled organisms belonging to fungi, which contain high amino acids, vitamins and other nutrients. Under aerobic conditions, yeast can convert water-soluble sugars into carbon dioxide and water. Under anaerobic conditions, yeast can use sugar as a carbon source to ferment and reproduce yeast cells. Therefore, the yeast can effectively decompose the sugar dissolved in the pool water, and rapidly reduce the biological oxygen consumption in the water body.
Gram-positive actinomycetes are aerobic bacteria. It can obtain substrates from photosynthetic bacteria, produce various antibiotics and enzymes, directly inhibit pathogens and promote the proliferation of beneficial microorganisms. Mixed use of actinomycetes and photosynthetic bacteria works better. It can also decompose lignin, cellulose, and chitin that are not easy to decompose under normal conditions, which is beneficial for animals and plants to absorb.
Sulfur bacteria are autotrophic bacteria that can oxidize inorganic sulfide to sulfuric acid and obtain energy from the oxidation of inorganic sulfur. Sulfur bacteria are widely distributed in pond bottom mud and water bodies, and their oxidation provides sulfuric acid sulfur elements available to aquatic plants, reducing the content of sulfur and hydrogen sulfide in the pond.
EM is the English abbreviation of effective microbiota. It is a microbial community formed by the compound culture of photosynthetic bacteria, lactic acid bacteria, yeast and other beneficial bacteria. They can form a complex and relatively stable micro-ecosystem through symbiotic and multiplication relationships. The main component of Yifuyuan's special bacteria liquid for aquatic products is EM bacteria. The beneficial microorganisms in EM undergo a series of decomposition and synthesis functions such as nitrogen fixation and photosynthesis, which can make the organic substances in the water form various nutrient elements for the growth and reproduction of themselves and bait organisms. , while increasing the dissolved oxygen in the water, reducing the content of toxic substances such as ammonia and hydrogen sulfide, and maintaining the balance of the aquaculture water environment. In addition, EM bacteria can also form a dominant flora in the intestinal tract to inhibit the activity of Escherichia coli, promote the body's digestion and absorption of bait, reduce the ammonia nitrogen content in excreta, and play a role in purifying water quality and promoting growth.