Reclassification of Gluconacetobacter hansenii strains and proposals of Gluconacetobacter saccharivorans sp. nov. and Gluconacetobacter nataicola sp. nov.

Ten strains previously assigned to Acetobacter hansenii (=Gluconacetobacter hansenii), Acetobacter pasteurianus LMG 1584 and eight reference strains of the genus Gluconacetobacter were reclassified by 16S rRNA gene sequencing, DNA-DNA similarity, DNA base composition and phenotypic characteristics. The A. hansenii strains and A. pasteurianus LMG 1584 were included in the cluster of acetic acid bacteria (family Acetobacteraceae) by 16S rRNA gene sequences. Further, they were separated into seven distinct groups by DNA-DNA similarity. DNA-DNA similarity group I was identified as G. hansenii. DNA-DNA similarity group II was retained as Gluconacetobacter sp., because DNA-DNA similarity between the strain and Gluconacetobacter entanii LTH 4560(T) could not be determined. This was due to a lack of availability of the type strain from any source. DNA-DNA similarity group III was regarded as a novel species, for which the name Gluconacetobacter saccharivorans sp. nov. (type strain, LMG 1582(T)=NRIC 0614(T)) is proposed. DNA-DNA similarity group IV included the type strains of Gluconacetobacter oboediens and Gluconacetobacter intermedius, and three A. hansenii strains. This group was identified as G. oboediens because high values of DNA-DNA similarity were obtained between the type strains and G. oboediens has priority over G. intermedius. DNA-DNA similarity group V was identified as Gluconacetobacter europaeus. DNA-DNA similarity group VI was regarded as a novel species, for which the name Gluconacetobacter nataicola sp. nov. (type strain, LMG 1536(T)=NRIC 0616(T)) is proposed. DNA-DNA similarity group VII was reclassified as Gluconacetobacter xylinus. The description of G. hansenii is emended.