Bacillus Subtilis

Updated: Sep 9, 2020

Description & Signifigance

Originally named Vibrio subtilis in 1835, this organism was renamed Bacillus subtilis in 1872. Other names for this bacteria also include Bacillus uniflagellatus, Bacillus globigii, and Bacillus natto. Bacillus subtilis bacteria were one of the first bacteria to be studied. These bacteria are a good model for cellular development and differentiation.

Bacillus subtilis cells are rod-shaped, Gram-positive bacteria that are naturally found in soil and vegetation. Bacillus subtilis grow in the mesophilic temperature range. The optimal temperature is 25-35 degrees Celsius (Entrez Genome Project). Stress and starvation are common in this environment, therefore, Bacillus subtilis has evolved a set of strategies that allow survival under these harsh conditions. One strategy, for example, is the formation of stress-resistant endospores.

Genome Structure

Only one DNA molecule is present in these cells. Bacillus subtilis has one circular chromosome. The total size of all the DNA is 4,214,814 bp (4.2 Mbp). 4,100 genes code for proteins. 53% of the protein-coding genes are only seen once, while 25% of the genome relates to families of genes that have undergone gene duplication.

A great portion of the genome corresponds to carbon source applications 192 of the 4,100 genes are considered indispensable, and an additional 79 are thought to be essential. Most of the essential genes are involved in metabolism. Half of the essential genes are responsible for processing information, one-fifth of them are responsible for cell wall synthesis, cell division, and shape, and one-tenth of them were responsible for the energetics of the cell. The essential genes that code for functions that are not known are 4%. Bacillus subtilis bacteria are capable of secreting antibiotics in great numbers to the exterior of the cell. Five signal peptidase genes were found to be important for this secretion function. Many of Bacillus subtilis cells' genes are responsible for antibiotic synthesis.