Method for producing citric acid by degrading coarse feed with naturally symbiotic mixed culture

Abstract

The invention relates to the field of renewable energy sources of biotechnology, in particular to a method for producing citric acid by degrading coarse feed with a naturally symbiotic mixed culture.The mixed culture YakQH5 is composed of anaerobic fungi (Neocallimastix frontalis) and methane bacteria (Methanobrevibacter gottschalkii), and is preserved in China General Microbiological Culture Collection Center on March 9th, 2020, and has the preservation number of CGMCC No.19299; the mixed culture YakQH5 can degrade 15 coarse feeds respectively and produce a large amount of citric acid, especially when alfalfa is used as a substrate, the yield of citric acid reaches up to 46.0 mM, composite antibiotics are added in the fermentation process, the mixed culture can be prevented from being polluted by bacteria in the fermentation process, and the anaerobic fermentation efficiency is further improved; and the mixed culture YakQH5 provided by the invention has an important industrial application value.

Description

Technical field[0001]The present invention relates to the field of biotech renewable energy, in particular a method of degrading crude feed to produce citric acid in natural symbiosis.Background technique[0002]The crude feed refers to a natural moisture content of 60% or less, and the coarse fiber content is equal to or higher than 18% in the dry matter, and feed, such as pasture, crop straw, leaves, alcohol and housing. The main components of the crude feed are lignocellulose, the fiber content, the protein, the low minerality, the poor equipage, and the livestock digestibility is low, thereby limiting its application. These crude feeds are very large, such as wheat straw, corn stalks, rice straw, oat straw, soybeans straw, soy straw, straw, alfalfa, bran, alcohol, tomato slag, wheat shell, etc., they are still in energy substances There is no reasonable development and utilization. It is currently used primarily to degrade and utilize a large amount of crude feed using microorgani...

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Problems solved by technology

[0005] The inventor first studied the anaerobic fermentation of the co-culture of grazing yak rumen anaerobic fungi and methanobacteria using wheat straw, corn straw and rice straw as substrates (Wei Yaqin. Research on the diversity of culture and its fiber degradation characteristics [D]. 2016.), by detecting gas production, polysaccharide hydrolase activity, various esterase activities, dry matter degradation rate, phenolic acid release, methane and acetic acid production Evaluate the straw degrading efficacy of the co-culture of anaerobic fungi and methanogens, in which the co-culture of anaerobic fungi and methanogens N.frontalis Yak16+M.ruminantium, Piromyces Yak18+M.ruminantium and O.joyonii Yak7+M.ruminantium respectively degrade The yields of acetic acid and methane produced by the three kinds of straws are high, but the yields of citric acid are extremely low, so the data of citric acid are not listed in the doctoral dissertation

So far, there are no reports about anaerobic fungi, or co-cultures of anaerobic fungi and methanogens degrading straw and other roughages to produce citric acid at home and abroad

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