Bacillus pumilus belongs to the bacterial kingdom, Sclerotium, Bacillus, Bacillus, Bacillaceae, Bacillus. The mycelium is rod-shaped, with a circular end, arranged in single or short chains, and the size of the mycelium is 1.2-1.5um × 2.0-4.0um, able to move, Gram positive, oval shaped spores, intermediate or secondary, size 1.0-1.2um × 1.5-2.0um. It can hydrolyze starch, degrade mannan, Xylan, cellulose, etc. Bacillus pumilus has two different forms of colonies: semi transparent and opaque. The two types of colonies were passaged separately, and semi transparent colonies can produce semi transparent and opaque colonies, each accounting for half of the total. However, opaque colonies only produce a small amount of semi transparent colonies during the passage process, and the semi transparent colonies disappear by the fourth generation