Method for producing branched β-1,3-glucooligosaccharides by fermentation of mixed fungi

Abstract

The invention discloses a method for producing branched β-1,3-glucooligosaccharides by fermenting mixed fungi, and belongs to the technical field of microbes and the field of fermentation technology. The invention provides a method for producing branched β-1,3-glucan oligosaccharides. Using this method, the bacterial strain capable of producing branched β-1,3-glucan is first inoculated into a fermentation medium and cultivated for 24- 72h, then inoculate the strain capable of producing endo-β-1,3-glucanase into the fermentation medium supplemented with bran and co-cultivate for 24-120h to make the branched β-1,3-glucanase in the fermentation broth The content of 3-gluco-oligosaccharides is as high as 2.51-4.61g / L, and the degree of polymerization of branched β-1,3-gluco-oligosaccharides in the fermentation broth is distributed between 4-15dp. Therefore, using this method to produce branched The β-1,3-glucan oligosaccharide has the advantages of high yield and uniform polymerization degree of the prepared β-1,3-glucan.

Description

technical field [0001] The invention relates to a method for fermenting and producing branched β-1,3-glucooligosaccharides by using mixed fungi, and belongs to the technical field of microbes and fermentation. Background technique [0002] β-1,3-glucooligosaccharide is an oligosaccharide obtained by linking multiple glucosides through β-1,3 glycosidic bonds. Its degree of polymerization is generally between 3 and 20dp. It has low calorific value, stability, safety and non-toxicity. , Difficult to be digested by the gastrointestinal tract and other physical and chemical properties. Studies have shown that β-1,3-glucooligosaccharides can target human, animal and plant cells through a variety of recognition functions, and perform functions such as recognition, aggregation and receptors. In addition, studies have shown that β-1,3-glucooligosaccharides have immunostimulatory functions, can enhance the ability of organisms to resist infectious diseases caused by bacteria, fungi, ...

AI Technical Summary

Problems solved by technology

Although β-1,3-glucan also has certain physiological functions, due to its poor water solubility, its physiological functions are far inferior to those of β-1,3-gluco-oligosaccharides at regular intake doses. Therefore, at present, Often produce β-1,3-gluco-oligosaccharides by degrading β-1,3-glucan

[0004] Existing methods for producing β-1,3-glucooligosaccharides by degrading β-1,3-glucan mainly include enzymatic, chemical and physical methods, however, these methods have serious defects

For example, Gao Rongwei tried to use β-1,3-glucanase to hydrolyze Sclerotin to produce β-1,3-glucooligosaccharides. However, the molecular weight range of the products produced by this method is relatively wide, ranging from 198 to 29416 Da. (i.e. 1 to 180dp), and the hydrolysis rate of this method is low, only a small part of the polysaccharide is degraded (specifically see the reference: Gao Rongwei. Fermentation process optimization of Sclerotinia scleroglucan accumulation [D]. Jiangnan University , 2014.); Lu Guangxing tried to use hydrochloric acid to degrade thermal gel to produce β-1,3-glucooligosaccharides, but the hydrochloric acid used was highly corrosive to the equipment, and the residual DMSO in the degradation process also polluted the environment , the feasibility is low (see references for details: Lu Guangxing. High-efficiency directional hydrolysis preparation of thermogel gluco-oligosaccharides and research on its biological activity [D]. Jiangnan University, 2015.); Chen et al. tried to use ultrasonic degradation of polysaccharides to Production of β-1,3-glucooligosaccharides, however, ultrasonication for 90 minutes can only degrade the molecular weight of polysaccharides to 43kDa (that is, 260dp), and the molecular weight is still very large, which cannot reach the molecular weight of β-1,3-glucooligosaccharides. Standard (see references for details: Chen J, Chen L, Lin S, et al. Preparation and structural characterization of apartially depolymerized beta-glucan obtained from Poria cocos, sclerotium byultrasonic treatment [J]. Food Hydrocolloids, 2015, 46(1) :1-9.), the above-mentioned defects all make the existing methods unable to realize the large-scale industrial production of β-1,3-glucooligosaccharides

[0005] In addition, the β-1,3-glucooligosaccharides produced by the existing enzymatic, chemical and physical methods are all linear β-1,3-glucooligosaccharides. The biological function of oligosaccharides is far inferior to that of branched β-1,3-glucosaccharides, which has become one of the main reasons why the quality of β-1,3-glucans cannot be improved in industrial production

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