Gluconacetobacter entanii sp nov., isolated from submerged high-acid industrial vinegar fermentations

Acetic acid bacteria have been isolated from submerged high-acid spirit vinegar fermentations in the Southern part of Germany. Four strains (LTH 4560(T), LTH 4341, LTH 4551 and LTH 4637) were characterized in more detail and it was revealed that they have in common certain properties such as requirement of acetic acid, ethanol and glucose for growth, and no overoxidation of acetate. Growth occurs only at total concentrations (sum of acetic acid and ethanol) exceeding 6.0%. A method for their preservation was developed. Comparative analysis of the 16S rRNA revealed sequence similarities of >99% between strain LTH 4560T and the type strains of the related species Gluconacetobacter hansenii. However, low levels of DNA relatedness (< 41%) were determined in DNA-DNA similarity studies. In addition, specific physiological characteristics permitted a clear identification of the strains within established species of acetic acid bacteria. The strains could also be differentiated on the basis of the distribution of IS element 1031 C within the chromosome. Based on these results, the new species Gluconacetobacter entanii sp. nov. is proposed for strain LTH 4560(T) ( = DSM 13536(T)). A 16S-rRNA-targeted oligonucleotide probe was constructed that was specific for G. entanii, and the phylogenetic position of the new species was derived from a 16S-rRNA-based tree.