title: Comparison of the morphology and deoxyribonucleic acid composition of 27 strains of nitrifying bacteria.
abstract: The gross morphology, fine structure, and per cent guanine plus cytosine (GC) composition of deoxyribonucleic acid of 27 strains of nitrifying bacteria were compared. Based on morphological differences, the ammonia-oxidizing bacteria were separated into four genera. Nitrosomonas species and Nitrosocystis species formed one homogenous group, and Nitrosolobus species and Nitrosospira species formed a second homogenous group in respect to their deoxyribonucleic acid GC compositions. Similarly, the nitrite-oxidizing bacteria were separated into three genera based on their morphology. The members of two of these nitrite-oxidizing genera, Nitrobacter and Nitrococcus, had similar GC compositions, but Nitrospina gracilis had a significantly lower GC composition than the members of the other two genera.
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001419:Bacteria / Q000032:analysis / Q000145:classification* / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D001431:Bacteriological Techniques; D002462:Cell Membrane; D002499:Centrifugation, Density Gradient; D002586:Cesium; D002712:Chlorides; D003470:Culture Media; D003596:Cytosine / Q000032:analysis; D004269:DNA, Bacterial / Q000032:analysis* / Q000302:isolation & purification; D006147:Guanine / Q000032:analysis; D009566:Nitrates / Q000096:biosynthesis; D009573:Nitrites / Q000096:biosynthesis / Q000378:metabolism*; D009576:Nitrobacter / Q000145:classification; D009606:Nitrosomonas / Q000145:classification; D010084:Oxidation-Reduction
chemical_list: D002712:Chlorides; D003470:Culture Media; D004269:DNA, Bacterial; D009566:Nitrates; D009573:Nitrites; D002586:Cesium; D006147:Guanine; D000641:Ammonia; D003596:Cytosine