Bacillus megaterium

Bacillus megaterium is a rod-like, Gram-positive, mainly aerobic spore forming bacterium found in widely diverse habitats. With a cell length of up to 4 µm and a diameter of 1.5 µm, B. megaterium is amongst the biggest known bacteria.  The cells often occur in pairs and chains, where the cells are joined together by polysaccharides on the cell walls^.
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. B. megaterium grows at temperatures from 3 °C to 45 °C, with the optimum around 30 °C. Some isolates from an Antarctic geothermal lake were found to grow at temperatures up to 63 °C.^[1]
 
B. megaterium has been recognized as an endophyte and is a potential agent for the bio control of plant diseases. Nitrogen fixation has been demonstrated in some strains of B. megaterium