Abstract
Using deoxyribonucleic acid hybridization (S1 nuclease method), we identified 12 hybridization groups (genospecies) containing 74 strains among 85 Acinetobacter strains studied. A total of 28 characters which allowed identification of the genospecies were applied to 266 strains. Of the 12 genospecies, 11 could be unambiguously identified. Genospecies 1 (Acinetobacter calcoaceticus sensu stricto) contained eight glucose-oxidizing strains which were unable to grow at 44°C and were isolated from soil, including the type strain of A. calcoaceticus. Genospecies 2, which contained 121 strains (mostly glucose oxidizers that were able to grow at 44°C), was named Acinetobacter baumannii sp. nov. (type strain, strain ATCC 19606). Genospecies 3 contained 15 strains that were able to oxidize glucose and to grow at 41°C but not at 44°C. Genospecies 4, which contained 23 hemolytic and proteolytic strains that were able to utilize DL-4-aminobutyrate but not DL-lactate, was named Acinetobacter haemolyticus sp. nov. (type strain, strain ATCC 17906). Genospecies 5, which contained 17 strains that were unable to oxidize glucose and able to utilize DL-lactate and L-histidine but not glutarate or azelate, was named Acinetobacter junii sp. nov. (type strain, strain ATCC 17908). Genospecies 6 contained only three hemolytic, proteolytic strains that were unable to utilize DL-lactate, malonate, or DL-4-aminobutyrate. Genospecies 7, which contained 23 strains that were unable to grow at 37°C and to oxidize glucose and utilized only a few carbon sources was named Acinetobacter johnsonii sp. nov. (type strain, strain ATCC 17909). A total of 34 strains had the characteristics of genospecies 8/9 (mostly glucose negative; utilized azelate but not Simmons citrate, glutarate, L-histidine, L-aspartate, L-leucine, β-alanine, or 2,3-butanediol). Genospecies 8 was Acinetobacter lwoffii sensu stricto since it contained the type strain of this species. Genospecies 9 could not be differentiated from genospecies 8. Genospecies 10 (four strains), 11 (four strains), and 12 (three strains) were differentiated by their nutritional patterns.