The enzyme pectinase is used in the production of fruit juices, and pectinase can be extracted from molds, yeasts and bacteria. Answer the following questions: (1) pectinase does not specifically refer to the (1) pectinase refers to the decomposition of pectin a class of enzymes, including pectinolytic enzymes, pectin esterase, polygalacturonase.

(2) before squeezing juice, pectinase and puree mixing insulation, the purpose is to break down the cell wall, improve the juice yield. After filtration, the juice should be treated with pectinase, the purpose is to break down the pectin in the juice, so that the juice becomes clear.

(3) If you consider both the shortening of the reaction time, but also consider the cost, the use of pectinase, in addition to controlling the temperature, pH and other external environmental conditions, but also to master the amount of pectinase.

(4) ① purification of yeast, the need to use solid medium, medium in addition to the need to provide water, inorganic salts and other major nutrients, the medium also need to meet the microbial growth conditions, such as pH, oxygen. In order to screen for high quality yeast containing highly active pectinase, pectin should be used as the only carbon source.

②Purification of yeast, the need for solid medium, the most common inoculation methods are plate scribing and dilution smear plate method.

The answer is:

(1) pectinolytic enzyme, pectin esterase, polygalacturonase

(2) increase the rate of juice to make the juice become clear

(3) pectinase dosage

(4) (1) pH, oxygen? pectin? ② solid? Plate scribing method and dilution coated plate method