Compound enzyme for producing reducing sugar by degrading maize straws

Abstract

The invention provides a compound enzyme for producing reducing sugar by degrading maize straws. The compound enzyme is prepared from pectase, cellulose, hemicellulase, ligninolytic enzyme, amylase, prolease, lipase and chitosanase. Compared with the prior art, 1) the yield of the reducing sugar by degrading the maize straws has high yield, and the gross amount of the reducing sugar of straws per gram reaches over 480 mg, so the compound enzyme has wide application prospect in the fuel alcohol industry; 2) compared with sugar preparation by acid process, severe acid pollution is prevented to facilitate subsequent fermentation; and 3) compared with monomer cellulose or simple compound enzyme, the pretreatment of steam explosion with high energy consumption is not required, and the amount of the reducing sugar is increased by over 1 time; meanwhile, glucose and xylose in a degradation product have high content, side products are few so as to contribute to subsequent fermentation, the industrial application value of the maize straws is improved, and the compound enzyme can be applied to production of single cell protein and fuel alcohol.

Description

technical field

[0001] The invention belongs to the technical field of biological enzyme engineering, and in particular relates to a special composite enzyme for degrading reducing sugar produced by corn stalks. Background technique

[0002] Straw cellulose is the most abundant renewable resource in the world, and it is a potential reserve resource for food, feed and energy industries. The annual output of corn stalks in my country is more than 200 million tons. Corn stalks are rich in cellulose, hemicellulose and lignin, and also contain some pectin, starch, protein and other substances. Among them, cellulose accounts for about 30% to 40%, which is a long-chain macromolecule formed by 8000 to 12000 glucose monomers connected by β-1,4-glycosidic bonds; hemicellulose is mainly composed of xylose and a small amount of arabinose , galactose, mannose, glucose and other components, accounting for about 35% to 48% of the dry matter of straw. The use of corn stalks in my country...

Examples

Embodiment 1

[0010] The compound enzyme formula: 15 parts of cellulase, 12 parts of hemicellulase, 8 parts of lignin degrading enzyme, 3 parts of amylase, 1 part of pectinase, 2 parts of protease, 2 parts of lipase, 3 parts of chitosanase share. Enzymatic hydrolysis method: crush corn stalks with a water content of less than 13% to 40 mesh, add 5 times the mass of phosphate buffer solution with pH 4.5, add the compound enzyme at 0.5% of the weight of the straw, and shake at a speed of 120r / min , Reacted for 30h at 45°C.

[0011] Enzymolysis effect: 531 mg of total reducing sugar is produced per gram of straw, and the reducing sugar is determined by DNS method.

Embodiment 2

[0013] The compound enzyme formula: 10 parts of cellulase, 8 parts of hemicellulase, 6 parts of lignin degrading enzyme, 1 part of amylase, 1 part of pectinase, 1 part of protease, 1 part of lipase, 1 part of chitosanase share. Enzymolysis method: crush corn stalks with a water content of less than 13% to 100 mesh, add 5 times the mass of pH 5 phosphate buffer, add the compound enzyme at 0.3% of the weight of the stalks, shake at a speed of 180r / min, 50 Under the condition of ℃, react for 25h.

[0014] Enzymolysis effect: 488 mg of total reducing sugar is produced per gram of straw, and the reducing sugar is determined by DNS method.

Embodiment 3

[0016] The compound enzyme formula: 13 parts of cellulase, 10 parts of hemicellulase, 7 parts of lignin degrading enzyme, 2 parts of amylase, 1 part of pectinase, 2 parts of protease, 2 parts of lipase, 3 parts of chitosanase part; enzymatic hydrolysis method: crush corn stalks with a water content of less than 13% to 60 mesh, add 3 times the mass of pH4 phosphate buffer, add the compound enzyme at 1.0% of the weight of the straw, and shake at a speed of 100r / min , 45 ℃ under the conditions of reaction 20h.

[0017] Enzymolysis effect: 508 mg of total reducing sugar is produced per gram of straw, and the reducing sugar is determined by DNS method.

technical field

[0001] The invention belongs to the technical field of biological enzyme engineering, and in particular relates to a special composite enzyme for degrading reducing sugar produced by corn stalks. Background technique

[0002] Straw cellulose is the most abundant renewable resource in the world, and it is a potential reserve resource for food, feed and energy industries. The annual output of corn stalks in my country is more than 200 million tons. Corn stalks are rich in cellulose, hemicellulose and lignin, and also contain some pectin, starch, protein and other substances. Among them, cellulose accounts for about 30% to 40%, which is a long-chain macromolecule formed by 8000 to 12000 glucose monomers connected by β-1,4-glycosidic bonds; hemicellulose is mainly composed of xylose and a small amount of arabinose , galactose, mannose, glucose and other components, accounting for about 35% to 48% of the dry matter of straw. The use of corn stalks in my country...

Examples

Embodiment 1

[0010] The compound enzyme formula: 15 parts of cellulase, 12 parts of hemicellulase, 8 parts of lignin degrading enzyme, 3 parts of amylase, 1 part of pectinase, 2 parts of protease, 2 parts of lipase, 3 parts of chitosanase share. Enzymatic hydrolysis method: crush corn stalks with a water content of less than 13% to 40 mesh, add 5 times the mass of phosphate buffer solution with pH 4.5, add the compound enzyme at 0.5% of the weight of the straw, and shake at a speed of 120r / min , Reacted for 30h at 45°C.

[0011] Enzymolysis effect: 531 mg of total reducing sugar is produced per gram of straw, and the reducing sugar is determined by DNS method.

Embodiment 2

[0013] The compound enzyme formula: 10 parts of cellulase, 8 parts of hemicellulase, 6 parts of lignin degrading enzyme, 1 part of amylase, 1 part of pectinase, 1 part of protease, 1 part of lipase, 1 part of chitosanase share. Enzymolysis method: crush corn stalks with a water content of less than 13% to 100 mesh, add 5 times the mass of pH 5 phosphate buffer, add the compound enzyme at 0.3% of the weight of the stalks, shake at a speed of 180r / min, 50 Under the condition of ℃, react for 25h.

[0014] Enzymolysis effect: 488 mg of total reducing sugar is produced per gram of straw, and the reducing sugar is determined by DNS method.

Embodiment 3

[0016] The compound enzyme formula: 13 parts of cellulase, 10 parts of hemicellulase, 7 parts of lignin degrading enzyme, 2 parts of amylase, 1 part of pectinase, 2 parts of protease, 2 parts of lipase, 3 parts of chitosanase part; enzymatic hydrolysis method: crush corn stalks with a water content of less than 13% to 60 mesh, add 3 times the mass of pH4 phosphate buffer, add the compound enzyme at 1.0% of the weight of the straw, and shake at a speed of 100r / min , 45 ℃ under the conditions of reaction 20h.

[0017] Enzymolysis effect: 508 mg of total reducing sugar is produced per gram of straw, and the reducing sugar is determined by DNS method.