Animated coloured scanning electron micrograph (SEM) of Viridibacillus arvi, Gram-positive, aerobic, spore forming, rod prokaryote (bacterium). Viridibacillus arvi (formerly known as Bacillus arvi) is a bacterial endospore forming bacillus (rod). Members of the genus Viridibacillus have the unique property of developing a green pigment, which is associated with sporulation. This image shows vegetative cells and terminally swollen sporulated cells. Unique chemotaxonomic characteristics including quinone and peptidoglycan cross linking structure differentiate these bacteria. Magnification: x4, 000 when shortest axis printed at 25 millimetres.