Subdivision of the genus Gluconacetobacter Yamada, Hoshino and Ishikawa 1998: the proposal of Komagatabacter gen. nov., for strains accommodated to the Gluconacetobacter xylinus group in the α-Proteobacteria

Abstract

The genus Gluconacetobacter is divided into two groups phylogenetically, phenotypically and ecologically: the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group. For the latter group, the genus Komagatabacter is newly introduced, and the type species of the new genus is designated as Komagatabacter xylinus (Brown 1886) comb. nov. Twelve species of the Gluconacetobacter xylinus group are transferred to the new genus as new combinations.

Introduction

The genus Gluconacetobacter Yamada et al. 1998 (Gluconoacetobacter sic) was introduced by an elevation of the subgenus Gluconacetobacter (ex Asai 1935) Yamada and Kondo 1985, with the following five species, Gluconacetobacter liquefaciens (Asai 1935) Yamada et al. 1998 (the type species), Gluconacetobacter xylinus (Brown 1886) Yamada et al. 1998, Gluconacetobacter hansenii (Gosselé et al. 1983) Yamada et al. 1998, Gluconacetobacter diazotrophicus (Gillis et al. 1989) Yamada et al. 1998 and Gluconacetobacter europaeus (Sievers et al. 1992) Yamada et al. 1998 (Yamada et al. 1997, 1998).

Upon the proposal of the subgenus Gluconacetobacter, only two species, Acetobacter (Gluconacetobacter) liquefaciens (Asai 1935) Gosselé et al. 1983 (the type species) and Acetobacter (Gluconacetobacter) xylinus (Brown 1886) Yamada 1984 were accommodated to the subgenus (Yamada and Kondo 1985). However, Yamada and Kondo (1985) did not consider that the two species were similar to each other chemotaxonomically and phenotypically (Asai et al. 1964; Leifson 1954; Yamada 1976, 1983; Yamada et al. 1969). Chemotaxonomically, for example, the former presented Q-10(Q-9), in which Q-9, a minor component of the respiratory quinone homologues, corresponded to Q-9, a major component of Q-9(Q-8) in strains of species of the genus Acetobacter, but the latter showed only Q-10, as found in strains of species of the genus Gluconobacter. Phenotypically, the former was motile with peritrichous flagella, but the latter was non-motile.

The species accommodated to the genus Gluconacetobacter are divided into two groups as mentioned above, namely the Gluconacetobacter xylinus group and the Gluconacetobacter liquefaciens group, on the basis of results obtained by 16S rRNA gene sequence analyses and by phenotypic characterization.

Yamada et al. (2000) calculated the 16S rRNA gene sequence similarities between the type strains of species belonging to Gluconacetobacter subclusters 1 and 2 to be 96.5–97.3%. Yamada (2000) transferred Acetobacter oboediens and Acetobacter intermedius to Gluconacetobacter subcluster 1, in which G. xylinus, G. hansenii and G. europaeus had been located, as Gluconacetobacter oboediens (Sokollek et al. 1998) Yamada 2000 and Gluconacetobacter intermedius (Boesch et al. 1998) Yamada 2000, but not to the Gluconacetobacter subcluster 2, in which G. liquefaciens and G. diazotrophicus had been located.

Dellaglio et al. (2005) reported that the two isolates that classified as Gluconacetobacter swingsii Dellaglio et al. 2005 and Gluconacetobacter rhaeticus Dellaglio et al. 2005 belonged phylogenetically to the genus Gluconacetobacter, in the Gluconacetobacter xylinus branch.

Lisdiyanti et al. (2006) described that the species of the genus Gluconacetobacter seemed likely to be divided into two subclusters phylogenetically, one consisting of G. liquefaciens, Gluconacetobacter sacchari Franke et al. 1999, G. diazotrophicus, Gluconacetobacter azotocaptans Fuentes-Ramírez et al. 2001 and Gluconacetobacter johannae Fuentes-Ramírez et al. 2001; and the other of G. swingsii, G. europaeus, Gluconacetobacter nataicola Lisdiyanti et al. 2006, G. xylinus, G. oboediens, G. intermedius, G. rhaeticus, Gluconacetobacter saccharivorans Lisdiyanti et al. 2006, G. hansenii and Gluconacetobacter entanii Schüller et al. 2000. The calculated pair-wise 16S rRNA gene sequence similarities were 95.7–97.6% between the two subclusters.

Yamada and Yukphan (2008) suggested that the Gluconactobacter liquefaciens group and the Gluconacetobacter xylinus group in the genus Gluconacetobacter can be distinguished from each other at the generic level from the phylogenetical, phenotypical and ecological points of view: (1) The calculated bootstrap value between the two groups in a 16S rRNA gene sequence phylogenetic tree derived from the neighbor-joining method was 70%. This indicated that the two groups were phylogenetically ‘not so tightly coupled.’ (2) The Gluconacetobacter liquefaciens group formed a large cluster along with the genera Acidomonas, Kozakia, Neoasaia, Asaia, Swaminathania, Gluconobacter and Acetobacter, rather than the cluster of the Gluconacetobacter xylinus group in a 16S rRNA gene sequence phylogenetic tree derived from the maximum parsimony method. The calculated bootstrap value was 74%. (3) A similar clustering was found in a 16S rRNA gene sequence phylogenetic tree derived from the maximum likelihood method. The calculated bootstrap value was 60%. Such a clustering was never found in acetic acid bacteria. For example, in the genus Gluconobacter, the calculated bootstrap values were 100% in the neighbor-joining method, 91% in the maximum parsimony method and 90% in the maximum likelihood method, in contrast to those of 70, 74 and 60% in the genus Gluconacetobacter. (4) Physiologically, strains of the Gluconacetobacter liquefaciens group produced 2,5-diketo-d-gluconate, γ-pyrone compounds and a water-soluble brown pigment, but strains of the Gluconacetobacter xylinus group did not. (5) Ecologically, the Gluconacetobacter liquefaciens group is plant-associated, namely strains of this group were isolated mostly from flowers, fruits, sugarcane, coffee plants and so on, but the Gluconacetobacter xylinus group is not necessarily plant-associated, namely, strains of this group were isolated mostly from fermented foods such as vinegar, nata de coco, tea fungus beverages and so on, in addition to the above-mentioned isolation sources.

This paper proposes Komagatabacter gen. nov., for strains of the species accommodated to the Gluconacetobacter xylinus group of the genus Gluconacetobacter, the family Acetobacteraceae Gillis and De Ley 1980.

Materials and methods

All the 16S rRNA gene sequences used in this study are present in the GenBank/EMBL/DDBJ databases. Multiple alignments of the cited DNA sequences were performed with the program Clustal X (version 1.8, Thompson et al. 1997). Alignment gaps and unidentified bases were eliminated. Distance matrices for the aligned sequences were calculated by the two-parameter method of Kimura (1980). Phylogenetic trees based on 16S rRNA gene sequences of 1,219 bases were constructed by the neighbor-joining method (Saitou and Nei 1987) and the maximum parsimony method (Felsenstein 1983), using the program MEGA (version 4.0, Tamura et al. 2007). In constructing a phylogenetic tree by the maximum likelihood method (Felsenstein 1981), the program PHYLIP (version 3.6, J. Felsenstein, University of Washington) was used instead of the program MEGA (version 4.0). The robustness of individual branches was estimated by bootstrapping with 1,000 replications (Felsenstein 1985), and bootstrap values are not shown if below 50% in phylogenetic trees. The type strain of Acidocella facilis was used as an outgroup.

The type strain of Gluconacetobacter kombuchae of the Gluconacetobacter xylinus group was examined for morphology. The bacterial strain was grown at 20°C for 18–20 h on an agar plate, which contained 2.0% glucose w/v, 1.0% ethanol v/v, 0.5% peptone w/v, 0.2% yeast extract w/v, 0.7% calcium carbonate w/v and 2.0% agar w/v. Motility was tested by the hanging-drop method, and cells were negatively stained and observed under an electron microscope.

Phenotypic features were determined by the methods of Asai et al. (1964), Gosselé et al. (1983), Navarro and Komagata (1999), Lisdiyanti et al. (2002, 2006), Yamada et al. (1969, 1976, 2000) and Yukphan et al. (2005, 2008, 2009, 2011).

Results and discussion

In a phylogenetic tree based on 16S rRNA gene sequences derived from the neighbor-joining method (Fig. 1), the five species classified in the Gluconacetobacter liquefaciens group were divided into two subclusters, one comprising the two species, G. liquefaciens and G. sacchari and the other including the three species, G. diazotrophicus, G. johannae and G. azotocaptans. The two subclusters were connected to each other with a bootstrap value of 97%. The former was not characterized by a nitrogen fixation capability, but the latter was (Gillis et al. 1989; Fuentes-Ramírez et al. 2001). In the Gluconacetobacter xylinus group, the 12 species constituted a cluster in which species that strictly require acetic acid for growth, such as G. europaeus and G. entanii, and that produce biocellulose, such as G. xylinus and G. nataicola, were likely to be distributed randomly, and there did not appear to be any rule governing their distribution (Table 1). Between the clusters of the Glconacetobacter liquefaciens group and the Glconacetobacter xylinus group, the calculated bootstrap value was 66%.

Fig. 1

Phylogenetic relationships of the genera Gluconacetobacter and Komagatabacter. A phylogenetic tree based on 16S rRNA gene sequences was constructed by the neighbor-joining method. The type strain of Acidocella facilis was used as an outgroup. Numerals at nodes indicate bootstrap values (%) derived from 1,000 replications. K. Komagatabacter

Table 1 Differential characteristics of the genera Gluconacetobacter and Komagatabacter. Gluconacetobacter strains: 1 Gluconacetobacter liquefaciens NBRC 12388^T (Navarro and Komagata 1999), 2 G. diazotrophicus LMG 7603^T (Gillis et al. 1989), 3 G. sacchari strain SRI 1794^T (Franke et al. 1999), 4 G. johannae strain CFN-Cf55^T (Fuentes-Ramírez et al. 2001), 5 G. azotocaptans strain CFN-Ca54^T (Fuentes-Ramírez et al. 2001); Komagatabacter strains: 6 Komagatabacter xylinus JCM 7644^T (Navarro and Komagata 1999), 7 K. hansenii NBRC 14820^T (Lisdiyanti et al. 2006), 8 K. europaeus strain DES 11^T (Sievers et al. 1992), 9 K. oboediens LTH 2460^T (Sokollek et al. 1998), 10 K. intermedius strain TF2^T (Boesch et al. 1998), 11 K. entanii strain LTH 4560^T (Schüller et al. 2000), 12 K. swingsii strain DST GL01^T (Dellaglio et al. 2005), 13 K. rhaeticus strain DST GLO2^T (Dellaglio et al. 2005), 14 K. saccharivorans LMG 1582^T (Lisdiyanti et al. 2006), 15 K. nataicola LMG 1536^T (Lisdiyanti et al. 2006), 16 K. kombuchae strain RG3^T (Dutta and Gachhui 2007), 17 K. sucrofermentans strain BPR 2001^T (Toyosaki et al. 1995; Cleenwerck et al. 2010)

In a phylogenetic tree based on 16S rRNA gene sequences derived from the maximum parsimony (MP) method (Fig. 2), the five species classified in the Gluconacetobacter liquefaciens group also grouped into two subclusters or subgroups. The cluster of the Gluconacetobacter xylinus group showed similar clustering, as found in the phylogenetic tree constructed by the neighbor-joining method. The calculated bootstrap value between the two clusters was 53%.

Fig. 2

Phylogenetic relationships of the genera Gluconacetobacter and Komagatabacter. A phylogenetic tree based on 16S rRNA gene sequences was constructed by the maximum parsimony (MP) method. The type strain of Acidocella facilis was used as an outgroup. The phylogenetic relationships were represented by a consensus tree of two most parsimonious trees. There were a total of 1,219 positions (bases) in the final dataset, of which 129 were parsimony informative. Consistency index = 0.441, retention index = 0.795, rescaled consistency index = 0.351, homoplasy index = 0.559. Numerals at nodes indicate bootstrap values (%) derived from 1,000 replications. K. Komagatabacter

In a phylogenetic tree based on 16S rRNA gene sequences derived from the maximum likelihood (ML) method (Fig. 3), a similar clustering was found in both the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group. The calculated bootstrap value was 42% between the two clusters.

Fig. 3

Phylogenetic relationships of the genera Gluconacetobacter and Komagatabacter. A phylogenetic tree based on 16S rRNA gene sequences was constructed by the maximum likelihood (ML) method. The type strain of Acidocella facilis was used as an outgroup. Numerals at nodes indicate bootstrap values (%) derived from 1,000 replications. K. Komagatabacter

It was noted that the 19 species assigned to the genus Acetobacter represented a similar clustering to the genus Gluconacetobacter (Figs. 1–3). One included Acetobacter aceti (the type species), Acetobacter estunensis and so on, and the other included Acetobacter pasteurianus, Acetobacter peroxydans and so on. Between the two clusters, the calculated bootstrap values were 72, 60 and 71% in the phylogenetic trees derived from the neighbour-joining method, the MP method and the ML method, respectively.

In all the three phylogenetic trees based on 16S rRNA gene sequences, the species assigned to the Gluconacetobacter xylinus group were phylogenetically independent of the Gluconacetobacter liquefaciens group, as indicated previously (Yamada and Yukphan 2008).

Dutta and Gachhui (2007) reported that the type strain of G. kombuchae was motile with polar flagellation. Considering the morphology of G. kombuchae assigned to the Gluconacetobacter xylinus group, the type strain of the species was examined for motility and flagellation. The type strain of G. kombuchae (= LMG 23726^T) was non-motile, and no flagellation was found (data not shown). The results obtained differed from those of Dutta and Gachhui (2007). The morphological property of the type strain observed in this study was reasonable and consistent with those of strains of the species assigned to the Gluconacetobacter xylinus group (Table 1).

As described above, the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group were differentiated phylogenetically from each other at the generic level. Morphologically, the former was motile with peritrichous flagella, and the latter was non-motile without any flagellation. Physiologically, the former produced a water soluble-brown pigment when grown on glucose/yeast extract/calcium carbonate medium while the latter did not. Biochemically, the former produced 2,5-diketo-d-gluconate and γ-pyrone compounds from d-glucose, but the latter did not. Ecologically, the former was plant-associated, but the latter was not necessarily plant-associated. These phylogenetic, phenotypic and ecological characteristics are enough to separate the Gluconacetobacter xylinus group from the Gluconacetobacter liquefaciens group at the generic level (Table 1) (Yamada and Yukphan 2008).

Furthermore, Cleenwerck et al. (2010) described that the genus Gluconacetobacter should not remain as a single genus on the basis of multilocus sequence analyses of the three housekeeping genes of dnaK, groEL and rpoB, as suggested by Yamada and Yukphan (2008). However, they stated that some of the above-mentioned phenotypic features were of little use for the differentiation of acetic acid bacteria and that, for this reason, other differentiating features should be looked for before splitting the genus. Our opinion is, however, quite different from theirs.

The above-mentioned phenotypic features are useful for differentiating the Gluconacetobacter xylinus group from the Gluconacetobacter liquefaciens group. In fact, one can exactly classify or identify such an acetic acid bacterium, without any problem and without any confusion, by the use of the phenotypic features mentioned above, as has already been done by Lisdiyanti et al. (2002), Loganathan and Nair (2004), Jojima et al. (2004) and Greenberg et al. (2006) (see Yamada and Yukphan 2008).

For example, a certain isolate can be assigned to or classified into the genus Gluconacetobacter, specifically to the Gluconacetobacter liquefaciens group but not to the Gluconacetobacter xylinus group, when it shows the oxidation of acetate and lactate and produces a characteristic water-soluble brown pigment (Table 1). The isolate also can be differentiated from some strains of the genus Gluconobacter and strains of the genus Tanticharoenia, all of which have no oxidation capability of acetate and lactate, and also from strains of the genus Swaminathania that have weak acetate and lactate oxidation, although all of them produce the water-soluble brown pigment (Yukphan et al. 2011). In contrast, an isolate that is non-motile and does not produce the water-soluble brown pigment can, in general, be assigned to or classified into the Gluconacetobacter xylinus group of the genus Gluconacetobacter, when it shows oxidation of acetate and lactate and has Q-10 as a major isoprenoid quinone (Table 1). The isolate also can be differentiated from strains of the genus Acetobacter that have Q-9 and the quite intense ability to oxidize acetate and lactate to carbon dioxide and water, from strains of the genus Acidomonas that grow on methanol by showing no growth on methanol, from strains of the genera Asaia, Kozakia and Granulibacter that show weak acetate oxidation, from strains of the genus Ameyamaea that are motile with polar flagella and weak oxidation of lactate and from the genera Gluconobacter, Neoasaia, Saccharibacter and Neokomagataea that have no oxidation of acetate and lactate (Yamada and Yukphan 2008; Yukphan et al. 2008, 2009, 2011). Finally, the systematic assignments or the taxonomic positions of the isolate based on routine identification methods can be confirmed phylogenetically, for example, by constructing a phylogenetic tree based on 16S rRNA gene sequences.

To date, only five genera of acetic acid bacteria include more than one species, namely Acetobacter Beijerinck 1898, Gluconobacter Asai 1935, Gluconacetobacter, Asaia Yamada et al. 2000 and Neokomagataea Yukphan et al. 2011. Others are monotypic genera and seem likely to be composed of rare microorganisms in distribution. When acetic acid bacteria, which are oxidative but not fermentative and grow at pH 3.5, are isolated from the natural environments, one will encounter mostly acetic acid bacteria that are classified into either the genus Acetobacter, Gluconobacter or Asaia. To discriminate these acetic acid bacteria at the generic level, the acetate and lactate oxidation test is useful (Asai et al. 1964; Yamada and Yukphan 2008). For example, in isolates to be assigned to the genus Acetobacter, which is characterized by Q-9 as a major quinone homologue, a deep blue color will appear fast and clearly. Isolates to be assigned to the genus Gluconobacter will generally show a clear yellow color. In the case of isolates to be assigned to the genus Asaia, which is characterized by little production of acetic acid from ethanol, color change will be very slow. In isolates to be assigned to the genus Gluconacetobacter, the color change to blue will be less vigorous compared to isolates to be assigned to the genus Acetobacter.

To divide isolates already assigned to the genus Gluconacetobacter into two groups, namely the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group, the characteristic brown-pigment production can be utilized. The former produces a water-soluble brown pigment, but the latter does not. It is noteworthy that, in our experience, there have been no exceptions to this routine identification method. Thus, one can identify a large number of isolates in a short period.

The 19 species assigned to the genus Acetobacter to date represent two clusters with low bootstrap values at the branching points in the phylogenetic trees (Figs.1–3) (Yamada and Yukphan 2008). At the present time, however, the species of the two clusters cannot be differentiated at the generic level, since there are likely to be no decisive phenotypic features to discriminate the two clusters or the two groups taxonomically, differing from the genus Gluconacetobacter.

The phylogenetic and phenotypic characteristics obtained above are enough to separate the Gluconacetobacter xylinus group at the generic level from the Gluconacetobacter liquefaciens group, and the species of the former group can appropriately be classified into a separate new genus. The name of the genus is Komagatabacter gen. nov.

Description of Komagatabacter gen. nov.

Komagatabacter (Ko.ma.ga.ta.bac’ter. N. L. masc. n. bacter from Gr. neut. n. baktron rod; N. L. masc. n. Komagatabacter Komagata rod, derived from Dr. Kazuo Komagata, Professor Emeritus, The University of Tokyo, Bunkyo-ku, Tokyo, Japan, who contributed to the bacterial systematics, especially of acetic acid bacteria).

Gram-negative rods and non-motile, measuring 0.5–0.8 × 1.0–3.0 μm. Colonies are white–creamy and smooth with entire margin or rough. Production of cellulose is positive or negative. Does not produce a water-soluble brown pigment on glucose/yeast extract/calcium carbonate medium. Produces acetic acid from ethanol. Growth is positive in the presence of 0.35% acetic acid v/v. In some strains, acetic acid is strictly required for growth. Oxidizes acetate and lactate to carbon dioxide and water. In some strains, acetate and lactate are not oxidized. In general, grows on glutamate agar and mannitol agar. Ammoniac nitrogen is generally assimilated on d-mannitol. Production of dihydroxyacetone from glycerol is positive or negative. Produces 2-keto-d-gluconate or 5-keto-d-gluconate from d-glucose, but 2,5-diketo-d-gluconate is not produced. γ-Pyrone compounds are not produced. In some strains, ketogluconates are not produced. Acid is produced from d-glucose, d-galactose, d-xylose, l-arabinose or ethanol, but not from d-fructose, l-sorbose, d-mannitol, d-sorbitol, maltose or lactose. Grows on d-glucose, d-fructose or d-mannitol, but not on lactose. A major isoprenoid quinone is Q-10. DNA base composition is 55.8–63.4 mol% G + C with a range of 7.6 mol%. The type species is Komagatabacter xylinus (Brown 1886) comb. nov.

Since the new genus was introduced, the following species should be transferred to the genus Komagatabacter.

Komagatabacter xylinus (Brown 1886) comb. nov.

Synonym: Gluconacetobacter xylinus (Brown 1886) Yamada, Hoshino and Ishikawa, Biosci Biotechnol Biochem 61: 1250, 1997 (Validation list no. 64, Int J Syst Bacterial 48: 327, 1998); Acetobacter xylinus (Brown 1886) Yamada, J Gen Appl Microbiol 29: 419, 1983 (Validation list no. 14, Int J Syst Bacteriol 34: 270, 1984)

Basonym: Acetobacter aceti subsp. xylinus (xylinum sic) (Brown 1886) De Ley and Frateur 1974 (Approved lists, Int J Syst Bacteriol 30: 239, 1980). The type strain is NCIMB 11664^T.

Komagatabacter hansenii (Gosselé, Swings, Kersters, Pauwels and De Ley 1983) comb. nov.

Synonym: Guconacetobacter hansenii Gosselé, Swings, Kersters, Pauwels and De Ley 1983) Yamada, Hoshino and Ishikawa, Biosci Biotechnol Biochem 61: 1250, 1997 (Validation list no. 64, Int J Syst Bacteriol 48: 327, 1998)

Basonym: Acetobacter hansenii Gosselé, Swings, Kersters, Pauwels and De Ley, Syst Appl Microbiol 4: 366, 1983 (Validation list no. 12, Int J Syst Bacterial 33: 896, 1983). The type strain is NCIMB 8746^T.

Komagatabacter europaeus (Sievers, Sellmer and Teuber 1992) comb. nov.

Synonym: Gluconacetobacter europaeus (Sievers, Sellmer and Teuber 1992) Yamada, Hoshino and Ishikawa, Biosci Biotechnol Biochem 61: 1250, 1997 (Validation list no. 64, Int J Syst Bacterial 48: 327, 1998)

Basonym: Acetobacter europaeus Sievers, Sellmer and Teuber, Syst Appl Microbiol 15: 391, 1992 (Validaton list no. 43, Int J Syst bacterial 42: 656, 1992). The type strain is DSM 6160^T.

Komagatabacter oboediens (Sokollek, Hertel and Hammes 1998) comb. nov.

Synonym: Gluconacetobacter oboediens (Sokollek, Hertel and Hammes 1998) Yamada, Int J. Syst Evol Microbiol 50: 226, 2000

Basonym: Acetobacter oboediens Sokollek, Hertel and Hammes, Int J Syst Bacterial 48: 939, 1998. The type strain is DSM 11826^T.

Komagatabacter intermedius (Boesch, Trček, Sievers and Teuber 1998) comb. nov.

Synonym: Gluconacetobacter intermedius (Boesch, Trček, Sievers and Teuber 1998) Yamada, Int J. Syst Evol Microbiol 50: 226, 2000

Basonym: Acetobacter intermedius Boesch, Trček, Sievers and Teuber, Syst Appl Microbiol 21: 228, 1998 (Validation list no. 67, Int J Syst Bacteriol 48: 1083, 1998). The type strain is DSM 11804^T. According to Lisdiyanti et al. (2006), this species is a later heterotypic synonym of Gluconacetobacter oboediens.

Komagatabacter entanii (Schüller, Hertel and Hammes 2000) comb. nov.

Basonym: Gluconacetobacter entanii Schüller Hertel and Hammes, Int J Syst Evol Microbiol 50: 2019, 2000. The type strain is DSM 13536^T.

Komagatabacter swingsii (Dellaglio, Cleenwerck, Felis, Engelbeen, Janssens and Marzotto 2005) comb. nov.

Basonym: Gluconacetobacter swingsii Dellaglio, Cleenwerck, Felis, Engelbeen, Janssens and Marzotto, Int J Syst Evol Microbiol 55: 2368, 2005. The type strain is LMG 22125^T.

Komagatabacter rhaeticus (Dellaglio, Cleenwerck, Felis, Engelbeen, Janssens and Marzotto 2005) comb. nov.

Basonym: Gluconacetobacter rhaeticus Dellaglio, Cleenwerck, Felis, Engelbeen, Janssens and Marzotto, Int J Syst Evol Microbiol 55: 2369, 2005. The type strain is LMG 22126^T.

Komagatabacter saccharivorans (Lisdiyanti, Navarro, Uchimura and Komagata 2006) comb. nov.

Basonym: Gluconacetobacter saccharivorans Lisdiyanti, Navarro, Uchimura and Komagata, Int J Syst Evol Microbiol 56: 2108, 2006. The type strain is LMG 1582^T.

Komagatabacter nataicola (Lisdiyanti, Navarro, Uchimura and Komagata 2006) comb. nov.

Basonym: Gluconacetobacter nataicola Lisdiyanti, Navarro, Uchimura and Komagata, Int J Syst Evol Microbiol 56: 2109, 2006. The type strain is LMG 1536^T.

Komagatabacter kombuchae (Dutta and Gachhui 2007) comb. nov.

Basonym: Gluconacetobacter kombuchae Dutta and Gachhui, Int J Syst Evol Microbiol 57: 356, 2007. The type strain is LMG 23726^T. According to Cleenwerck et al. (2009), this species is a later heterotypic synonym of Gluconacetobacter hansenii.

Komagatabacter sucrofermentans (Toyosaki, Kojima, Tsuchida, Hoshino, Yamada and Yoshinaga 1996) comb. nov.

Synonym: Gluconacetobacter sucrofermentans (Toyosaki, Kojima, Tsuchida, Hoshino, Yamada and Yoshinaga 1996) Cleenwerck, Vos and Vuyst, Int J Syst Evol Microbiol 60: 2282, 2010

Basonym: Acetobacter xylinus (Brown 1886) Yamada 1984 subsp. sucrofermentans Toyosaki, Kojima, Tsuchida, Hoshino, Yamada and Yoshinaga, J Gen Appl Microbiol 41:312, 1995 (Validation list no. 58, Int J Syst Bacteriol 46: 836, 1996). The type strain is JCM 9730^T.