NEW, SPORULATING, DENITRIFYING, MESOPHILIC BACTERIUM - BACILLUS-AZOTOFORMANS N-SP

  • 1 January 1976
    • journal article
    • research article
    • Vol. B127  (3) , 351-361
Abstract
The described bacterium was isolated by enrichment culture in peptone broth inoculated with garden soil, pasteurized and then incubated under N2O at 32.degree. C. It is a gram-negative rod, motile with peritrichous flagella, and producing oval spores without exosporium in swollen sponrangia. Cells have the thick walls, mesosomes and persistant septa characteristic of gram-positive bacteria. It lacks fermentative activity, does not attack carbohydrates, has complex growth requirements, and will grow anaerobically only if 1 of the following electron acceptors is present: .**GRAPHIC**. N2O, .**GRAPHIC**. and fumarate. Nitrate, nitrite and N2O are denitrified with production of N2. The microorganism is mesophilic, gives a positive oxidase reaction, synthesizes a type c cytochrome, and does not hydrolyze gelatin, starch or Tween 80. The following enzymes are present: nitrate reductase A, respiratory nitrite reductase, tetrathionate and fumarate reductases, L-glutamate dehydrogenase and superoxide dismutase. The following enzymes are absent: thiosulfate reductase, urease, lecithinase, arginine dihydrolase, L-alanine dehydrogenase, phenylalanine desaminase, and catalase. The GC % of its DNA is 39. The bacterium described can be considered to be a new species. The name B. azotoformans sp. nov. is proposed.