A Comparative Survey of the Nutrition and Physiology of Mesophilic Species in the Genus Bacillus

SUMMARY: Two hundred and ninety-six strains of mesophilic species of the genus Bacillus were isolated from soil and examined for the characters described principally by Smith, Gordon the number of nutritionally aberrant strains in each species was very small. The characteristic nutritional patterns were: B. subtilis, B. licheniformis and B. megatherium grew with ammonia as nitrogen source and in the absence of added growth factors. B. cercus and B. brevis grew in absence of added growth factors but required mixtures of amino-acids instead of ammonia only. B. pumilus and B. polymyxa both grew with ammonia + biotin, and B. macerans grew with ammonia + biotin + aneurin. B. alvei required amino-acids + aneurin; B. circulans and B. coagulans required amino-acids and usually both aneurin and biotin; some strains of B. circulans had more complex requirements. Some strains of B. sphaericus required amino-acids + aneurin, others required biotin as well, and all of the strains of B. sphaericus var. fusiformis required amino-acids + aneurin + biotin. The strains of B. pasteurii were the most heterogeneous in their nutritional requirements, the components ammonium ion, amino-acids, aneurin, biotin and nicotinic acid being involved. All strains required amino-acids and aneurin; in addition, biotin or nicotinic acid and sometimes ammonium ion were required, depending on the particular strain.