Minimal Nutritional Requirements of Bacillus sphaericus NCTC9602 and 26 other Strains of this Species: the Majority Grow and Sporulate with Acetate as Sole Major Source of Carbon

Abstract

Bacillus sphaericus NCTC 9602 grew and sporulated in a simple chemically defined minimal medium containing only KH2PO4/Na2HPO4 buffer, pH 7.2, 15 mm-ammonium sulphate, inorganic salts and sodium acetate (as sole source of carbon); no vitamins were needed. The organisms contained the characteristic enzymes of the glyoxylate cycle (isocitrate lyase and malate synthase) but lacked pyruvate dehydrogenase. Isocitrate dehydrogenase and 2-oxoglutarate dehydrogenase were both present. The minimal nutritional requirements of 26 other strains of B. sphaericus were investigated. Three of these (including the type culture) grew and sporulated in the above minimal medium, and a further 13 strains grew and sporulated when only biotin and thiamin were added. Two more strains grew in the minimal medium plus these vitamins and glutamic acid. Four of the remaining strains needed several amino acids, but not acetate, and four other strains required a purine as well as amino acids.