A study ofBacillus subtilisand related organisms

A group of species, comprising Bacillus subtilis and related organisms, may be differentiated from other members of the genus Bacillus by ( a ) morphology and ( b ) the production of acid and acetylmethylcarbinol from glucose. The group may be divided into three species: (1) B. subtilis Cohn emend . Prazmowski, the synonyms of which include B. aterrimus, B. globigii, B. mesentericus, B. niger, B. panis , and B. vulgatus . (2) B. pumilus Gottheil, which resembles strains of (1) that produce a smooth glossy growth. It differs in failing to secrete diastase and in other features, but its separation as a distinct species is still an open question. It is sometimes identified as B. mesentericus . (3) B. licheniformis (Weigmann) Gibson, the synonyms of which include B. subtilis (as used by Ford), B. globigii and B. mesentericus ruber . This species may be differentiated from (1) and (2) by its cultural characters, slow proteolytic action, vigorous CO 2 production and ability to grow anaerobically.