Microbes in the Spotlight: Bacillus megaterium

You’re back! And we’re on part three of our ‘Microbes in the Spotlight’ series! Let’s focus on Bacillus megaterium today. This is another bacterium that falls under the Bacilli class.

Latin Name: Bacillus megaterium

Common name: None that I could find

Appearance under the microscope:Rod-like cells up to 4 µm in length and 1.5 µm in diameter, if it was gram-stained it would be purple-coloured. Under the epifluorescent microscope at 63x there was evidence of DAPI and GFP. The cells were also in pairs or chains.

Preferred habitat: Found in widely diverse habitats

Optimum Temperature: 30°C but can grow at temperatures of 3 °C-45 °C

Bacillus megaterium  under a light microscope at 4.5x viewed using the AmScope software with a MU1000 camera

Bacillus megaterium epifluorecent image with a phase contrast filter at 63x indicating TRANS-DAPI-GFP 

Bacillus megaterium is aerobic, spore-forming, gram-positive and amongst the biggest known bacteria. Although it has an optimum temperature, its ability to grow within a large range is reflective of the occupation of a diversity of habitats. For example, some Bacillus megaterium have been found in an Antarctic geothermal lake, with temperatures up to 63 °C!

As always, there’s a reason for the gif. The Bacillus megaterium arrived in a tube of nutrient agar, with the instructions to culture at 30°C. As with Sporosarcina ureae, Luria broth agar (LBA) was used. We’re not pausing for a recipe here, check out the Sporosarcina ureae post.

Bacillus megaterium on day three of incubation at 30°C on LBA

The LBA plates were incubated at 30 °C. Growth was observed after one day of incubation. Out of the microorganisms in this series, this was the fastest growing probably an indication of its characteristic ability to grow in various conditions.

Again, there was no contamination, but it would be interesting to explore alternative media

Want to find out more?

De Vos, P. et al. Bergey's Manual of Systematic Bacteriology: Volume 3: The Firmicutes. Springer (2009)

Vary, S. P. et al. Bacillus megaterium — from simple soil bacterium to industrial protein production host. Appl Microbial Biotechnol 76:957–967 (2007)

Bunk, B. et al. A short story about a big magic bug. Bioengineered Bugs 1:85–91 (2010)

Dib, E. G. et al. Nonhemolytic, Nonmotile Gram-Positive Rods Indicative of Bacillus anthracis. Emerg Infect Dis. 9:1013–1015 (2003)