Taxonomic heterogeneity of strains comprising Gluconacetobacter hansenii

The taxonomic standing of Gluconacetobacter hansenii was clarified through phenotypic characteristics, quinones, DNA base composition, DNA relatedness , and the production of gluconic and ketogluconic acids from glucose. All s trains that Gossele et al. (Syst. Appl. Microbiol., 4, 338-368, 1983) emplo yed in the establishment of Acetobacter hansenii (=G, hansenii) were used i n this study. Phenotypic differences were shown among the strains of G. han senii, suggesting heterogeneity within the species. The major ubiquinone wa s Q-10 for all strains of G. hansenii, except for strain IFO 3296, which wa s characterized by Q-9. This excluded IFO 3296 from the species G, hansenii and placed it in the genus Acetobacter. DNA relatedness revealed four dist inct homology groups (I, Ii, III, and IV) among strains of the species. Gro up I was distinguished from the other genomic groups by a lower G+C range f rom 58.9 to 59.2 mol%. Groups II, III, and IV showed higher G-I-C contents of 60.4 to 62.2, 60.8, and 61.7 mol%, respectively. Groups I and IV produce d both 2-and 5-ketogluconic acids from glucose, and Group III produced only 2-ketogluconic acid. Group II included strains that produced both 2- and 5 -ketogluconic acids and strains that produced only 2-ketogluconic acid. It is clear that G, hansenii consists of genotypically heterogeneous strains c omprising four homology groups (I, II, III, and IV). Since group I contains the type strain (IFO 14820(T)=LMG 1527(T)) of the species, this group is d esignated as the species G, hansenii.