Microbial agent for preventing and treating white stool syndrome of litopenaeus vannamei as well as preparation method and application of microbial agent

Abstract

The invention relates to a microbial agent for preventing and treating the white stool syndrome of litopenaeus vannamei as well as a preparation method and application of the microbial agent. The microbial agent is fermented powder prepared by performing spray drying on fermentation liquid of enterococcus faecalis. The preparation method of the microbial agent for preventing and treating the whitestool syndrome of the litopenaeus vannamei comprises the following steps: sequentially performing shake-flask culture, first-stage seed culture, second-stage seed culture and fermentation culture onthe enterococcus faecalis, and then drying to obtain the microbial agent for preventing and treating the white stool syndrome of the litopenaeus vannamei. In the application of the microbial agent forpreventing and treating the white stool syndrome of the litopenaeus vannamei, the microbial agent is blended into feed in proportion, and then the feed is used for feeding the litopenaeus vannamei ina pond in which white stool is formed for treatment or not formed for prevention. The microbial enterococcus faecalis agent can significantly inhibit growth and reproduction of pathogens such as vibrio cholerae, edwardsiella tarda and aeromonas hydrophila, has broad-spectrum bacteriostasis, can prevent and treat the white stool disease of the litopenaeus vannamei, has the preventing and treatingeffect of 78% or above, and has a significant effect.

Description

technical field [0001] The invention belongs to the technical field of microbial bacterial agent disease prevention, and relates to a bacterial agent for preventing and treating white stool syndrome of Litopenaeus vannamei and its preparation method and application. Background technique [0002] According to the 2017 China Fishery Yearbook data, the output of Litopenaeus vannamei in China reached 932,300 tons in 2016. However, since 2010, the frequent white stool syndrome of prawns has been one of the major problems affecting the sustainable development of the shrimp aquaculture industry. one. The main symptoms of white stool syndrome of Litopenaeus vannamei are: the feces of sick prawns are slender and white (such as cotton thread), sticky, and gather in a large number in the air outlet floating under the water surface, and emit a foul smell. At present, Litopenaeus vannamei is mainly treated with antibiotics such as enrofloxacin, or combined with some traditional Chinese ...

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Problems solved by technology

[0005] (2) Cao Haipeng et al. believe that the pathogenesis may be due to the massive growth and proliferation of Vibrio cholerae in the intestinal tissue of Litopenaeus vannamei, adhesion to the intestinal mucosa, and the production of virulence factors on the surface, causing damage to the intestinal wall and mucosa, and further through the hemolymphatic circulation to the The hepatopancreas tissue reproduces and produces toxins in it, leading to hepatopancreas enlargement, erosion and other lesions, which eventually lead to dysfunction of the hepatopancreas and intestines, causing the disease and death of Litopenaeus vannamei

There is no report on the prevention and treatment of white stool syndrome of Litopenaeus vannamei with Enterococcus faecalis