What is the Difference Between Bacillus Subtilis and Bacillus Cereus?

Bacillus subtilis and Bacillus cereus are both rod-shaped, aerobic, spore-forming bacteria belonging to the Bacillus genus. However, they have some key differences in their genome, ecological background, and cell wall composition:

1. Genome: B. subtilis has a smaller genome than B. cereus and contains no plasmids, while B. cereus strains are known to harbor one or more plasmids. The B. cereus group genomes are about 25% larger than the B. subtilis genome and have a lower GC content.
2. Ecological Background: Genome analysis indicates that B. subtilis is a benign soil dweller specialized in degrading plant-derived polysaccharides, while B. cereus is adapted to thrive as a pathogen or parasite, preferring a more carnivorous diet of proteins and amino acids.
3. Sporulation: B. cereus spores are surrounded by an exosporium, whereas B. subtilis spores are not. Although many genes that play a role in sporulation are believed to be conserved among Bacillus species, there may be important differences between B. cereus and B. subtilis sporulation genes and their expression.
4. Cell Wall Composition: The carbohydrate composition of bacterial cell walls in the B. cereus group is different from that of B. subtilis. The absence of teichoic acids is suggested as a means to differentiate B. subtilis and B. cereus group bacteria.
5. Pathogenicity: B. cereus is known to cause foodborne illnesses, producing toxins and endospores. In contrast, B. subtilis is not known to cause illnesses in humans.

In summary, Bacillus subtilis and Bacillus cereus differ in their genomes, ecological backgrounds, sporulation properties, cell wall compositions, and pathogenicity.

Comparative Table: Bacillus Subtilis vs Bacillus Cereus

Here is a table comparing the differences between Bacillus subtilis and Bacillus cereus:

Both Bacillus subtilis and Bacillus cereus are gram-positive, rod-shaped bacteria that are motile, possess flagella, and form endospores. They also share similarities in core metabolism, amino acids, lipid, nitrogen, phosphorus, and sulfur metabolism, as well as chemotaxis. However, they differ in their ability to ferment mannitol and produce lecithinase, their optimal growth temperatures, virulent factors, and carbohydrate utilization.