The biological characteristics, physiological function, research and development of Clostridium difficile and its application in aquatic feed.

China is the world's largest aquaculture country, since 1989 has been 28 consecutive years of total production of aquatic products ranked first in the world, and show a continuous healthy development trendIn 2017, the country's total production of aquatic products was 64.4533 million tons, of which 4905.99 million tons were farmed, accounting for 76.12% of the total production, and the fishing output was 15.3934 million tons, accounting for 23.88% of the total output (2018 China Fisheries Statistics Yearbook)In the new era of increasing pressure on food safety and environmental protection, changing the way aquaculture production and promoting green aquaculture production are the basic requirements for the sustainable development of the aquaculture industryThe use of green production technology, to create a good aquaculture environment, enhance the self-immunity of aquatic animals, scientific norms of the use of antibiotics, avoid the hidden dangers of antibiotic use, to prevent the emergence of drug-resistant bacteria, in order to ensure the safety of aquatic products and aquaculture environment from antibiotic strainsChina attaches great importance to the scientific use of antibiotics, aquaculture end limit anti-reduction has also been mentioned on the agenda, the indiscriminate use of antibiotics, not only the problem of violations, seriously related to criminal law sanctionsIn order to strengthen the management of veterinary antimicrobial drugs, curb the resistance of animal-derived bacterial drugs, ensure the production safety, food safety, public health safety and ecological safety of the aquaculture industry, promote the green development of the aquaculture industry, safeguard the health of the people, and promote the sustained and healthy development of the economic and ecological society, the Ministry of Agriculture issued on June 23, 2017 the National Action Plan to curb the resistance of animal-derived bacteria (2017-2020) and On April 20, 2018, the General Office of the Ministry of Agriculture and Rural Affairs issued the Notice on the Pilot Work on The Reduction of The Use of Veterinary Antibacterial Drugs, which stated that the "Exit Action" should be promoted to reduce the use of veterinary antibiotics, and the phase-out of growth-promoting antimicrobial drugs and the drastic elimination of more than 100 high-risk veterinary drug productsBased on food safety and environmental pressure, China's implementation of anti-resistance action and aquaculture green production development mode transformation, antibiotic replacement product development and application ushered in the spring, probiotics, acidifiers, enzymes, slow release of stinking fatty acids and Chinese herbal medicine and its extracts and other green alternative stakes of antibiotics have broad prospects, including probiotic products because of green environmental protection, non-toxic side effects, no residue, a wide range of effects, non-resistant and other potential alternatives to antibiotics1933, DrMiyazaki, of Chiba Medical University in Japan, first discovered and reported Clostridium bochinoIn 1992, Clostridium buturic acid was introduced from the Russian Institute of Microbiology by the Institute of Microbiology of Heilongjiang Provincial Academy of Sciences, and has been planted in China since thenIn 2003, the European Union approved Clostridium butyl acid as a feed additive for broilers and weaned piglets, and in July 2009 China's Ministry of Agriculture approved the production and use of clostridium pmitalate, a new feed additive, and in December 2013 it was included in Appendix II of the Feed Additive Variety Catalog (2013)With the continuous deepening of research and development of Clostridic acid in the scientific and industrial fields and the demand of aquaculture green production, its application research work in aquaculture with feed has attracted people's attention, and has achieved some resultsThis paper summarizes the research and development of clostridium coccita and its application in aquatic feed, with a view to accumulating information for future research and development workthe biological properties of clostridium 1 butyric acid bacteriaand its physiological function1.1 butyric clostridium(Cbutyric) clostridium(Cbutyric) bacteria, also known as clostridium acid bacteria, C.bbutyric acid spores, butyric acid bacteria, co-called "lactic acid bacteria that produce spores", belonging to the firmicobacteria (⁃ CClostrideuris, Clostridella, Clostridium, for a specialist anaerobic G-spores, whose cell walls contain D, L-diaminocosic dacid and glucose, peripheral whiplash, movementable, occasionally see silky bacteria, spore spores, eccentric or sub-endospora cells proliferonas, So that it adheres only to the intestinal cells of aquatic animals without damaging the cells, it can also co-exist with the intestinal beneficial bacteria of aquatic animals such as Bifidotruumbifidum, Lactobacillus (Lactobacillus sp), Copro⁃phil bacteria) and promote their development and regulate the micro-ecological balance of the intestinesIt can be used as a probiotic either alone or in combination with a variety of strainsAt present, the study found that Clostridium hydrophilis is sensitive to only a few antibiotics, such as neomycin, pioneermycin, vancomycin and tetracycline, and has a strong tolerance to a variety of antibiotics (beta-lactam, cycloseolee, quinolones, etc.), and its biological activity is not affected when used with these antibiotics, but also can enhance the therapeutic effect, non-toxic side effects1.2 butyric acid clostridium 1 physiological function1.2.1 inhibit the reproduction of harmful bacteria, promote the reproduction of "indigenous" beneficial bacteria, and regulate the micro-ecological balance of the intestineCdifficile as an "indigenous bacteria" in the intestines of animals, can be well planted in the intestines, and effectively prevent the abnormal proliferation of pathogens and corrupt bacteria in the intestines, promote the proliferation and development of beneficial bacteria in the intestines, thereby correcting intestinal flora disorders and reducing the production of enterotoxinsIn vitro experiments have found that Clostridium hydrophilic bacteria can effectively inhibit vibrio anguillarum, Edwardsi ⁃ella tarda, aeromonas hydrophila, and better than streptomycin sulfate; Cys miiuy) Clostridium difficile can effectively inhibit the growth of Ecoli, significantly increase the relative proportion of pseudomonas in the aerobic bacteria structure, reduce the proportion of monobacteria and short bacteria, and also effectively inhibit fish pathogenic bacteria - salmonella (Salmonel ⁃ enterlaitididis) and paralytic visolyalymolycicoccus ⁃)generally believe that clostridium conoccis on theof microorganisms is mainly the effect of the metabolites of Clostridium pediting volatile fatty acids, there are studies show that in the metabolized products of Clostridium pedific acid also involved in the inhibition of pathogensThe addition of C C C2 in the feed promotes the proliferation of Bifidobacteria in the intestines and back intestines offish, inhibits the growth and reproduction of E coli in the intestines, does not affect the total number of intestinal anaerobic bacteria, reduces the total number of post-intestinal aerobic bacteria, and changes the structure of the post-intestinal aerobic bacteria, consolidates the status of the dominant group of pseudomonascoccus, reduces the proportion of bacteria withnomeycoliethane, enterobacteria and short-term bacteria Clostridium butyric acid is straight rod-like or slightly bent, cultured in liquid medium, Clostridium p mitric acid produces a large number of gases, and precipitation is more late The irregular circular colonies of white or grayish or cream or creamy or creamy yellow form on the agar plate, an omelette-like, mid-bulge, moist, smooth, opaque, slightly sour odor The suitable growth and reproduction temperature of Clostridium difficile is 25-37 degrees C, which is mainly found in cheese, natural yogurt, human and animal waste and soil in nature, and can produce spores and resist adverse environments Clostridium butyric acid has biological properties such as heat resistance, acid resistance and bile resistance The study showed that Clostridium coccal storides survived 98% after heat treatment at 80 degrees C, 30 min, 90 oC and 10min heat treatment, 95% survived after heating at 90 oC and 20min, and 80% survived after heating 100 oC and 5min These properties make Clostridium butrine a probiotic suitable for adding in aquatic feed and can be used effectively by aquatic animals, with strong resistance In addition, Clostridium butyric acid is resistant to strong acidic acid and gall acid and bile acid, can withstand pH 1.0-5.0, the most suitable pH 4.0-9.8 Clostridium acid can promote the fermentation of a variety of carbohydrates to produce short-chain fatty acids such as butyric acid, lactic acid, acetic acid, and produce B vitamins, vitamin K and other bioactive substances, but also produce amylase, protease, glycoside enzymes, cellulas, phospholipid synthase and lipase, which helps to supplement aquatic animal nutrients, improve the digestion and absorption rate of aquatic animals to feed the metabolites of C difficion of butyric acid - butric acid can stimulate enteroride clostridic acid used in the prevention and treatment of early death syndrome of shrimp significant effect, its metabolites butyric acid and lactic acid is the shrimp intestinal advantage probiotic group - Bifidobacteria probiotics, can promote the rapid proliferation of Bifidobacteria in the shrimp body, stabilize the intestinal micro-ecological environment At the same time, butyric acid and lactic acid can create acidic environment, eliminate superoxides, reduce the potential for redox reduction, inhibit the growth of harmful bacteria such as Vibrio in shrimp, reduce the occurrence of enteritis; Group, white prawn digestion system is simple so it is easier to form a solid intestinal biological barrier; Lactobacillus acidophilus is one of the gastrointestinal origin advantage strains, for both anaerobic bacteria, and complete anaerobic Clostridium difficile combined can promote the implantation of intestinal beneficial bacteria, quickly establish the intestinal advantage of the flora, stabilize the intestinal environment, enhance the body's resistance The factors that affect the micro-ecological balance of intestines in aquatic animals include both external environmental factors and host factors The external environment is mainly produced by changing the physiological function of the host, such as beneficial bacteria, by producing bacteriobacteria, antibiotics and their metabolites, as well as competing for nutrition, competing for space to prevent the invasion of passing bacteria, to maintain their own stability Ecological balance, can maintain the normal physiological functions of the host, such as nutrition, immunity, digestion and so on 1.2.2 to produce short-chain fatty acids such as butyric acid to repair the intestinal mucosa short-chain fatty acids such as butyric acid and lactic acid, the metabolized products of butyric acid and lactic acid, are the main energy source of epithelial cells in the intestinal mucosal membrane of aquatic animals, and the butyric acid of intestinal epithelial cells is metabolized by beta-oxidation in the hydroxymethyl diylcoenzyme A cycle Adequate butyric acid and lactic acid can protect the vitality of intestinal cells in aquatic animals, promote the secretion of viscoproteins and defenses, strengthen the close connection of epithelial cells, promote the rapid repair of the intestinal mucosa, restore its physiological function The addition of clostridium conobacteria in shrimp feed can enhance the digestion of the shrimp digestive tract, improve its intestinal health, improve the body's immunity and anti-stress ability, and promote shrimp growth The addition of Clostridium pedagome in the feed can increase the content of short-chain fatty acids in the intestines of Litopenaeus vannamei and Mar⁃supenaeus japonicus, increase the thickness of the intestinal epithelial cell layer, improve intestinal health, and repair intestinal damage Feeding with Clostridium p mitric acid with feed 56 d, effectively improved the intestinal morphology structure of L van ⁃namei, and the intestinal fluff height increased significantly 1.2.3 reduces the ambient pH of the intestine and inhibits the inflammatory response in the intestine clostridium acid is metabolized in a unique way, can ferment sugars to produce a large number of butyric acid, acetic acid and lactic acid and a small amount of short-chain fatty acids such as procitine and torinacid, in the gastrointestinal tract, short-chain fatty acids can not only reduce its pH, but also directly absorbed at the production site, while stimulating intestinal peristalsis, helpto treat related diseases Such as the addition of clostriditemia in the crustacean with feed, can effectively reduce the probability of crustacean white stool and drag, greatly reduce the occurrence of Vannabin prawn empty intestine, inhibit the apoptosis of intestinal epithelial cells and intestinal mucosa inflammatory response, such as intestinal atrophy, bending, intestinal tract, stooling, redness and other phenomena 1.2.4 enhances the body's immune function and antioxidant capacity Clostridium acid has the role of activating macrophages and NK cells, but also can stimulate the immune activity of the intestinal mucosa, induce the production of SIgA or IgM, affect certain cytokines involved in immune regulation, and enhance the body's immunity and the number of white blood cells (CD4 plus) The addition of p truffle p mitalates in aquatic animals with feed can not only enhance the body's immune function and resistance to disease, but also help to improve the antioxidant and stress resistance of aquatic animals After feeding the added C difficile feed, the phagocytosis of oncorhynchus mykiss increased significantly, the amount of white blood cell hyperoxy ions increased significantly, and the resistance to Vibrio disease was significantly increased Feeding the added Clostridium clostridium acid feed significantly increased the activity offish serum phenol oxidase (PO) and acid phosphatase (ACP) activity, as well as the activity of lysozyme (LZM) in serum and body table mucus, and immunoglobulin M (IgM) content the fish fed the feed added by active or inactivated Clostridium p editing, the activity of mucus and lysozyme in serum increased significantly The addition of piscoccal pedifying in the combined feed of Sciaenops ocellatus increased the activity of enzymes such as LZM, ACP and PO in the U.S red fish serum and body table mucus, the concentration of IgM in plasma, the level of serum complement C3, and the activity of phage respiratory bursts, thus enhancing its immune function Pearl dragon bile grouper (Epinephelus fuscoguttatus♀ x Epinephelus lanceola⁃tus ♂) Young fish feed to add phenobacteria, which can enhance the level of expression of the HSP70 gene in the liver, head and spleen of young fish, as well as increase the activity of LZM enzyme, white protein and globulin content To enhance the body's nonspecific immunity and reduce the cumulative mortality rate of pearl dragon bile grouper after Vibrio har⁃veyi was attacked; The addition of clostridite or its fermentation solution (including Clostridium plyse and its metabolites) to the pearl dragon bile plaque feed has a catalytic effect on nonspecific immunoasase activity, including Bacillus cereus BC-01, Lactobacillus acidophilus (Lacto ⁃silus acidophilus LAG01) and Clostiumbu.co.bisco.