The subgenera Moraxella and Branhamella and the nine species included in these subgenera were inadvertently omitted from the Approved Lists of Bacterial Names and have never been revived according to Rule 28a of the Bacteriological Code (1990 Revision). The author requests that these names be revived and considered to be validly published in the 'Index of the bacterial and yeast nomenclatural changes published in the International Journal of Systematic Bacteriology since the 1980 Approved Lists of Bacterial Names (1 January 1980 to 1 January 1985)', which appears in the July 1985 issue of the International Journal of Systematic Bacteriology. Another problem is the status of the species included in the subgenera Moraxella and Branhamella because the Bacteriological Code (1990 Revision) does not envisage the status of a species transferred into a subgenus. The same is true for a species transferred into a subspecies. The author requests that such species be considered as new combinations and, according to this, proposes to modify Rule 34a of the Bacteriological Code (1990 Revision).

Some repetitions, omissions or errors have been made in the Validation Lists published in the International Journal of Systematic Bacteriology and they are corrected in this paper.

Thirty-six strains of acetic acid bacteria classified in the genera Acetobacter, Gluconobacter, and Acidomonas were examined for their partial base sequences in positions 1220 through 1375, 156 bases, of 16S rRNA. The strains of the Q10-equipped Gluconobacter species examined were divided into two subgroups, which included the type strains of Gluconobacter oxydans, the type species of the genus Gluconobacter, and of a second species, Gluconobacter cerinus, respectively. The base differences numbered four between the two type strains. The strains of the Q9-equipped species examined classified in the type subgenus Acetobacter of the genus Acetobacter were not very distant phylogenetically from those of the genus Gluconobacter. The calculated number of base differences was 9-6 between the type strains of G. oxydans and G. cerinus and the type strains of Acetobacter aceti and Acetobacter pasteurianus. In contrast, the strains of the Q10-equipped species examined classified in the subgenus Gluconoacetobacter of the genus Acetobacter were very distant phylogenetically from those of the Acetobacter and Gluconobacter species mentioned above. The number of base differences was calculated to be 14-8. Furthermore, the strains of the methanol-assimilating, Q10-equipped species of the genus Acidomonas examined were located in phylogenetically isolated positions. The type strain of Acidomonas methanolica (identical to Acetobacter methanolicus), the type species of the genus Acidomonas, had 16-9 base differences. The data obtained here indicated that the members of the subgenus Gluconoacetobacter of the genus Acetobacter can be distinguished at the generic level. The new genus Gluconoacetobacter was proposed with the type species, Gluconoacetobacter liquefaciens, in recognition of the genus Acidomonas along with the genera Acetobacter and Gluconobacter in the classification of the acetic acid bacteria.