Nitrogen-fixing and cellulose-producing Gluconacetobacter kombuchae sp nov., isolated from Kombucha tea

A few members of the family Acetobacteraceae are cellulose-producers, while only six members fix nitrogen. Bacterial strain RG3(T), isolated from Kombucha tea, displays both of these characteristics. A high bootstrap value in the 1 6S rRNA gene sequence-based phylogenetic analysis supported the position of this strain within the genus Gluconacetobacter, with Gluconacetobacter hansenii LMG 1527(T) as its nearest neighbour (99.1 % sequence similarity). It could utilize ethanol, fructose, arabinose, glycerol, sorbitol and mannitol, but not galactose or xylose, as sole sources of carbon. Single amino acids such as L-alanine, L-cysteine and L-threonine served as carbon and nitrogen sources for growth of strain RG3(TT). Strain RG3 produced cellulose in both nitrogen-free broth and enriched medium. The ubiquinone present was Q-10 and the DNA base composition was 55.8 mol% G + C. It exhibited low values of 5.2-27.77 % DNA-DNA relatedness to the type strains of related gluconacetobacters, which placed it within a separate taxon, for which the name Gluconacetobacter kombuchae sp. nov. is proposed, with the type strain of related gluconacetobacters, which placed it within a separate taxon, for which the name Gluconacetobacter kombuchae sp. nov. is proposed, with the type strain RG3(T) (=LMG 23726(T) = MTCC 6913(T))