There are three major groups of microorganisms that produce enzymes: filamentous fungi, yeasts and bacteria, mainly using aerobic bacteria

The strains and usage of several major industrial enzymes are as follows:

Amylases

Amylase hydrolyzes starch to produce pasty maltooligosaccharides and maltose. It is mainly produced by submerged fermentation of Bacillus subtilis and Bacillus licheniformis, and the latter produces thermostable enzymes. In addition, it is also produced by deep and semi-solid fermentation of strains of Aspergillus and Rhizopus, which is suitable for food processing. Amylase is mainly used in sugar making, textile desizing, fermentation raw material processing and food processing. Glucoamylase can hydrolyze starch into glucose, and is now almost entirely produced by submerged fermentation of Aspergillus niger for sugar production, alcohol production, fermentation raw material processing, etc.

protease

The most used strains and production varieties. Use Bacillus licheniformis, Bacillus pumilus and Bacillus subtilis to produce bacterial protease by submerged fermentation; use Streptomyces, Aspergillus submerged fermentation to produce neutral protease and Aspergillus acid protease, used for leather depilation, fur softening, pharmaceutical, food industry; Some bacteria of the genus Mucor undergo semi-solid fermentation to produce rennet, replacing the rennet originally extracted from the stomach of calves in the manufacture of cheese.

glucose isomerase

A breed that developed rapidly in the 1970s. First obtain Streptomyces cells by submerged fermentation, and after immobilization, convert the glucose liquid into a syrup containing about 50% fructose, which can be used in the food industry instead of sucrose. The use of amylase, glucoamylase and glucose isomerase to make corn starch into fructose has become one of the emerging sugar industries.