High-lactase producing aspergillus oryzae and fermentation and enzyme producing method thereof

Abstract

The invention discloses a strain of high-lactase producing aspergillus oryzae and a fermentation and enzyme producing method thereof, and belongs to the technical field of bioengineering. The bacterial stain is specifically an aspergillus oryzae strain CA-08, and a preservation number is CGMCC No.14137. The bacterial strain is subjected to submerged fermentation through a liquid 50-L tank, throughsupplementing, fermentation culture is conducted for 105 h, and an enzyme-producing average is 100762 U / mL. According to the method of liquid-state lactase fermentation, an optimal pH range of produced lactase is 4.0-7.0, optimal operative temperature is 80 DEG C, after heat preservation is conducted at 80 DEG C for 1 h, the residual enzyme activity is 89.5%, and after heat preservation is conducted at 80 DEG C for 2h, the residual enzyme activity is 58.9%, so that the lactase has good heat resistance, and can be widely applied to industrial production.

Description

Technical field: [0001] The invention belongs to the technical field of bioengineering, and in particular relates to a strain of Aspergillus oryzae with high lactase production and a method for fermenting and producing the enzyme. Background technique: [0002] Lactase is a tasteless, odorless, light brown liquid after dissolution, non-toxic and no side effects of biological enzyme preparation, the enzyme can be used to degrade lactose into galactose and glucose, and also has the transfer function of galactoside. It is also an important nutrient in mammalian milk. It can catalyze the hydrolysis of lactose into galactose and glucose, and is mostly used in the dairy industry. Lactase activity in mammals typically decreases physiologically with age, so lactase deficiency is a widespread worldwide problem. [0003] Lactase exists in plants such as almonds and apricots and in the small intestine of young mammals. Microorganisms such as bacteria, molds and yeasts can also produc...

AI Technical Summary

Problems solved by technology

A lot of work has been done abroad since the 1960s and at home since the 1980s, but there is still a big gap between domestic and foreign countries. Lactase has not been widely used in China's food and dairy industries. The main reason is that lactase The unit yield of Lactase is relatively low. Most of the lactases sold on the market are intracellular enzymes, which need to be broken into cells to obtain. The extraction and purification process is complicated, the cost is high, the action temperature of the enzyme is low, and the heat resistance is poor. It is easy to be infected with bacteria in industrial production. Narrow scope of application

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