Bacillus megaterium is a rod-like, Gram-positive, mainly aerobic spore forming bacterium found in widely diverse habitats.[1][2] With a cell length of up to 4 µm and a diameter of 1.5 µm, B. megaterium is amongst the biggest known bacteria.[3] The cells often occur in pairs and chains,[1] where the cells are joined together by polysaccharides on the cell walls[citation needed].
In the 1960s, prior to the development of Bacillus subtilis, B. megaterium was the main model organism among Gram-positive bacteria for intensive studies on biochemistry, sporulation and bacteriophages. Recently, its popularity has started increasing in the field of biotechnology for its recombinant protein production capacity