A kind of galactosidase and polynucleotide encoding this enzyme

Abstract

The invention discloses beta-galactosidase (beta-D-galactosidase, EC3.2.1.23) cloned from metagenome of a thermal spring at the temperature of 65 DEG C in Eryuan in Dali as well as nucleotide encoding the galactosidase. The galactosidase has relatively high catalytic activity at the temperature of 37-55 DEG C, can serve as a lactose degradation and disaccharides synthesis catalyst and has polysaccharide and galactose residues stored in hydrolyzed organisms. In addition, the galactosidase has a glucoside transforming effect, and some functional oligosaccharides, such as galactooligosaccharide can be generated. The oligosaccharides are hardly digested by small intestines and are water-soluble dietary fibers which are low in molecular weight and not viscous. The oligosaccharides serve as multiplication factors of bifidobacterium species in intestines and only can be utilized by the bifidobacterium species, the multiplied bifidobacterium species are competitively antagonistic to growth of putrefying bacteria, the generated toxins and enzymes are reduced, and an effect of regulating intestinal tract is achieved.

Description

technical field [0001] The invention belongs to the field of biotechnology, and specifically relates to a β-galactosidase cloned from the macrogenome of Eryuan Hot Spring in Dali, a polynucleotide encoding the enzyme, and a method and application of producing the enzyme through DNA recombination technology. Background technique [0002] Pig milk contains about 3-5% lactose. When the small intestinal mucosal β-galactosidase gene of suckling piglets is deficient or acquired insufficient, lactose indigestion will occur. After the undecomposed and absorbed lactose enters the colon, it is absorbed by the intestinal tract. The existing bacteria ferment into small molecule organic acids such as acetic acid, propionic acid, butyric acid, etc., and produce some gases such as methane, H 2 , CO 2 etc., most of these products can be reabsorbed by the colon, and the unabsorbed or undecomposed lactose can cause symptoms such as borborygmus, abdominal distension, abdominal pain, gas, diar...

AI Technical Summary

Problems solved by technology

[0002] Pig milk contains about 3-5% lactose. When the small intestinal mucosal β-galactosidase gene of suckling piglets is deficient or acquired insufficient, lactose indigestion will occur. After the undecomposed and absorbed lactose enters the colon, it is absorbed by the intestinal tract. The existing bacteria ferment into small molecules of organic acids such as acetic acid, propionic acid, butyric acid, etc., and produce some gases such as methane, H 2 , CO 2 etc., most of these products can be reabsorbed by the colon, and the unabsorbed or undecomposed lactose can cause symptoms such as borborygmus, abdominal distension, abdominal pain, flatulence, and diarrhea, which will seriously affect the health of suckling piglets for a long time to grow

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