Genus Bacillus

Genus Bacillus

Classification

Domain: Bacteria
Phylum: Firmicutes
Class: Bacilli
Order: Bacillales
Family: Bacilliaceae
Genus: Bacillus
Species: B.anthracis, B.subtilis, B.cereus, B.licheniformis, B.coagulans, B.macerans, B.mycoides, B.megaterium, B.mesentricus

Introduction

Sporogenous, rod shaped bacteria are classified into two genera, the aerobic Bacilli and then anaerobic Clostridia. The genus Bacillus consists of aerobic bacilli forming heat resistant spores.
Gram positive but tend to be decolorized easily so as to appear Gram variable or even frankly Gram negative. Species of Genus Bacillus are generally motile with peritrichous flagella, Anthrax bacillus being a notable exception.
Members of this group exhibit great diversity in their properties.

The genus include psychrophilic, mesophilic and thermophilic species, the maximum temperatures for vegetative growth ranging from about 25 ˚C to above 75 ˚C and the minimum from about 5 ˚C to 45 ˚C.
Salt tolerance varies from less than 2% to 25% NaCl.
Spores are ubiquitous, being found in the soil, dust, water and air and constitute the commonest contaminants in bacteriological culture media.

Bacillus anthracis, the causative agent of anthrax is the major pathogenic species.
Bacillus cereus can cause food-borne gastroenteritis, gangrenous mastitis in cattle and rarely abortion in cattle, sheep and horses. It has been associated with infertility in mares.
Bacillus licheniformis is a rare cause of bovine abortion.