Commensalibacter nepenthis sp. nov. and Commensalibacter oyaizuii sp. nov., from fluid in a Nepenthes pitcher cup and a butterfly (Junonia lemonias) in Thailand.

Two novel Gram-negative, aerobic, rod-shaped, non-motile bacteria, strains TBRC 10068T and TBRC 16381T, were isolated from a fluid sample from a close-pitcher cup (Nepenthes gracilis) and an insect sample (Junonia lemonias), respectively. Comparing the 16S rRNA gene sequences with those found in EzBioCloud's publicly available databases revealed that the two strains exhibited a close genetic relationship with Commensalibacter intestini A911T; the calculated sequence similarities were 98.56 and 97.70  %, respectively. The average nucleotide identity and digital DNA-DNA hybridization values of the two Commensalibacter strains, as well as those of their closely related type strains, were found to be lower than the species demarcation threshold of 95 and 70 %, respectively. The phylogenomic analysis of strains TBRC 10068T and TBRC 16381T showed that they belong to the genus Commensalibacter. However, they formed distinct lineages separate from all other strains of Commensalibacter by use of 81 bacterial core genes. In addition, the comparative genomic analysis revealed that the core orthologues of strains TBRC 10068T and TBRC 16381T, compared to the closely related type strains of Commensalibacter species, had distinct genetic profiles. Strain TBRC 10068T contained 163 unique genes, whereas strain TBRC 16381T contained 83. The three Commensalibacter species possessed Q-9 as the primary isoprenoid quinone homologue. The results of a polyphasic taxonomic investigation indicated that strains TBRC 10068T and TBRC 16381T represent two separate new species within the genus Commensalibacter. The species were designated as Commensalibacter nepenthis sp. nov. with the type strain TBRC 10068T (=KCTC 92798T) and Commensalibacter oyaizuii sp. nov. with the type strain TBRC 16381T (=KCTC 92799T).

Rhodoferax potami sp. nov. and Rhodoferax mekongensis sp. nov., isolated from the Mekong River in Thailand.

Four newly discovered Gram-stain-negative bacteria, designated as BL00010T, BL00058, D8-11T and BL00200, were isolated from water samples collected at three hydrological monitoring stations (namely Chiang Saen, Chiang Khan and Nong Khai) located along the Mekong River in Thailand. An investigation encompassing phenotypic, chemotaxonomic and genomic traits was conducted. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that all four isolates represented members of the genus Rhodoferax. These isolates were closely related to Rhodoferax bucti KCTC 62564T with a similarity of 99.59%. The major fatty acids of the four novel isolates included C16:0 and C16:1ω7c and/or C16 : 1ω6c, whereas the major respiratory quinone was identified as ubiquinone Q-8. In addition, phosphatidylethanolamine was identified as a major polar lipid in these bacteria. The genomes of BL00010T, BL00058, D8-11T and BL00200 were similar in size (3.88-4.01 Mbp) and DNA G+C contents (59.5, 59.3, 59.5 and 59.3 mol%, respectively). In contrast to R. bucti KCTC 62564T and Rhodoferax aquaticus KCTC 32394T, the newly discovered species possessed several genes involved in nitrite and nitrile metabolism, which may be related to their unique adaptation to nitrile-rich environments. From the results of the pairwise analysis of average nucleotide identity of the whole genome and digital DNA-DNA hybridisation, it was evident that BL00010T and D8-11T represented two novel species, for which we propose the nomenclature Rhodoferax potami sp. nov., with the type strain BL00010T (TBRC 17198T = NBRC 116413T), and Rhodoferax mekongensis sp. nov., with the type strain D8-11T (TBRC 17307T = NBRC 116415T).

Leeia speluncae sp. nov., isolated from Stegodon Sea Cave in Thailand.

A novel Gram-stain-negative, obligately aerobic, short rod-shaped and motile bacterium, designated strain BC00092T, was isolated from brackish ground water collected in Stegodon Sea Cave located at Satun UNESCO Global Geopark, Satun Province, Thailand. The phylogenetic analysis of BC00092T based on 16S rRNA gene sequences revealed that the strain represented a member of the genus Leeia and was closely related to Leeia oryzae DSM 17879T (96.68 %) and Leeia aquatica IMCC25680T (94.89 %). The average nucleotide identity and digital DNA-DNA hybridization values calculated from the whole-genome sequences between BC00092T and closely related type strains of species within the family Leeiaceae were lower than the species demarcation threshold values of 95 and 70 %, respectively. Moreover, five conserved signature indels of members of the family Leeiaceae were found in the protein sequences from the annotated assembled genome of BC00092T. According to the results of the polyphasic taxonomic study, strain BC00092T represents a novel species within the genus Leeia, for which the name Leeia speluncae sp. nov. is proposed. The type strain is BC00092T (TBRC 13508T = KCTC 92111T).

Novosphingobium kaempferiae sp. nov., a phosphate-solubilizing bacterium isolated from stem of Kaempferia marginata Carey.

A Gram-stain-negative, aerobic, rod-shaped, non-spore-forming and yellow-pigment-producing bacterium, designated as Sx8-5T, was isolated from stem tissue of Kaempferia marginata Carey in Kanchanaburi Province, Thailand. The strain exhibited tricalcium phosphate solubilizing activity. Its taxonomic position was investigated using a polyphasic approach. Sx8-5T grew at 25-37 °C (optimum 30 °C), pH 6-9 (optimum 7) and with 0 and 1% NaCl (optimum 0 %). According to the 16S rRNA gene phylogeny, Sx8-5T represents a member of genus Novosphingobium and shared the highest sequence similarities to Novosphingobium barchaimii LL02T of 99.4 % and shared sequence similarities with other species of the genus Novosphingobium of less than 99.4 %. The whole-genome size was 5.7 Mb, comprised of one contig, with a DNA G+C content of 66 %. The average nucleotide identity using BLASTn (ANIb) or MUMMER (ANIm) values for whole genome comparisons between Sx8-5T and Novosphingobium barchaimii LL02T and six closely related type strains were 72.33-82.14 % and 83.82-87.38 %, respectively, and the digital DNA-DNA hybridization (dDDH) values ranged from 21.0 to 28.6% when compared with the type strains of the members of the genus Novosphingobium. Major fatty acids were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C16 : 0 and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), respectively. Polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, unidentified phospholipids and unidentified polar lipids. The major isoprenoid quinone was Q-10. According to results obtained using a polyphasic approach, Sx8-5T represents a novel species of the genus Novosphingobium, the name Novosphingobium kaempferiae sp. nov. is proposed. The type strain is Sx8-5T (=JCM 35076T =TBRC 15600T).

Neokomagataea anthophila sp. nov., an osmotolerant acetic acid bacterium isolated in Thailand and emended description of the genus Neokomagataea.

A novel Gram-stain-negative, rod-shaped, non-motile, aerobic bacterium isolated from a sea bean flower [Canavalia rosea (Sw.) DC.] collected in Surat Thani Province, Thailand, and designated as AH18T was characterized on the basis of polyphasic taxonomy. The phylogenetic analysis of 16S rRNA gene revealed that strain AH18T represented a member of the genus Neokomagataea. In the 16S rRNA gene sequence analysis, the strain's closest phylogenetic neighbour was Neokomagataea thailandica TBRC 376T. The draft genome size of strain AH18T was 2613495 bp, and its DNA G+C content was 52.0 mol%. The strain showed 90.3 and 76.3% pairwise-determined whole-genome average nucleotide identity and 39.8 and 19.6% digital DNA-DNA hybridization values with N. thailandica TBRC 376T and N. tanensis TBRC 7768T, respectively. The 16S rRNA gene sequences and phylogenomic analysis revealed that the strain clustered with the members of the genus Neokomagataea but was located in a distinct branch closely related to N. thailandica TBRC 376T. The predominant cellular fatty acids of the strain were summed feature 8 (C18:1 ω6c and/or C18:1 ω7c), C16:0 and C18:1 2OH (>5%). The major respiratory ubiquinone was Q-10. In addition, strain AH18T was substantiated by differences in several physiological characteristics and by MALDI-TOF profiling. On the basis of the results obtained from phenotypic, chemotaxonomic, phylogenetic and genomic analyses, the strain clearly represented a novel species within the genus Neokomagataea, for which the name Neokomagataea anthophila sp. nov. (AH18T=TBRC 2177T=NBRC 115156T) is proposed. An emended description of the genus Neokomagataea is also given.

Acetobacter garciniae sp. nov., an acetic acid bacterium isolated from fermented mangosteen peel in Thailand.

Two isolates, MS16-SU-2T and MS18-SU-3, obtained from fermented mangosteen peel in vinegar were suggested to constitute a new species assignable to the genus Acetobacter based on the results of 16S rRNA gene sequencing. The two isolates showed the highest sequence similarity (98.58%) to Acetobacter tropicalis NBRC 16470T and Acetobacter senegalensis LMG 23690T. However, the calculated similarity values were lower than the threshold for species demarcation. The phylogenetic analysis showed that the branches of the two isolates were separated from other Acetobacter species, and the two isolates constituted a new species in the genus Acetobacter. The genomic DNA of isolate MS16-SU-2T was sequenced. The assembled genome of the isolate was analysed, and the results showed that the highest average nucleotide identity value of 75.9 % was with Acetobacter papayae JCM 25143T and the highest digital DNA-DNA hybridization value of 25.1 % was with Acetobacter fallax LMG 1636T, which were lower than the cutoff values for species delineation. The phylogenetic tree based on the genome sequences showed that the lineage of isolate MS16-SU-2T was most closely related to A. papayae JCM 25143T and Acetobacter suratthaniensis TBRC 1719T, but separated from the branches of these two species. In addition, the two isolates could be distinguished from the type strains of closely related species by their phenotypic characteristics and MALDI-TOF profiles. Therefore, the two isolates, MS16-SU-2T (=TBRC 12339T=LMG 32243T) and MS18-SU-3 (=TBRC 12305), can be assigned to an independent species within the genus Acetobacter, and the name of Acetobacter garciniae sp. nov. is proposed for the two isolates.

Donghicola mangrovi sp. nov., a member of the family Rhodobacteraceae isolated from mangrove forest in Thailand.

Two novel Gram-stain-negative, rod-shaped and non-motile bacterial strains, designated B5-SW-15T and C2-DW-16, were isolated from water collected in mangrove forests in Ranong Province, Thailand. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains B5-SW-15T and C2-DW-16 belonged to the genus Donghicola and were most closely related to Donghicola tyrosinivorans DSM 100212T (98.2 and 98.1 %, respectively) and Donghicola eburneus DSM 29127T (97.7 and 97.6 %, respectively). The average nucleotide identity and digital DNA-DNA hybridization values between strain B5-SW-15T, strain C2-DW-16 and related species were 95.8 and 71.6 % (to strain C2-DW-16), 76.8 and 21.3 % (to D. tyrosinivorans DSM 100212T) and 80.3 and 24.2 % (to D. eburneus DSM 29127T), respectively. The predominant cellular fatty acids (>5 %) were summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), C16 : 0 and C12 : 1 3-OH. Ubiquinone Q-10 was the sole respiratory quinone. DNA G+C contents of the isolates were 61.0 and 61.2 mol% based on whole genome sequences. Strains B5-SW-15T and C2-DW-16 contained aminolipid, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol as the major polar lipids. On the basis of the results from phenotypic, chemotaxonomic and phylogenetic analyses, strains B5-SW-15T and C2-DW-16 constitute a novel species of the genus Donghicola in the family Rhodobacteraceae for which the name Donghicola mangrovi sp. nov. is proposed. The type strain is B5-SW-15T (=BCC 56522T=TBRC 9562T=KCTC 72743T).

Komagataeibacter diospyri sp. nov., a novel species of thermotolerant bacterial nanocellulose-producing bacterium.

Thermotolerant bacterial nanocellulose-producing strains, designated MSKU 9T and MSKU 15, were isolated from persimmon and sapodilla fruits, respectively. These strains were aerobic, Gram-stain-negative, had rod-shaped cells, were non-motile and formed white-cream colonies. Phylogeny based on the 16S rRNA gene sequences revealed that MSKU 9T and MSKU 15 represented members of the genus Komagataeibacter and formed a monophyletic branch with K. swingsii JCM 17123T and K. europaeus DSM 6160T. The genomic analysis revealed that overall genomic relatedness index values of MSKU 9T with K. swingsii JCM 17123T and K. europaeus DSM 6160T were ~90 % average nucleotide identity (ANI) and ≤58.2 % digital DNA-DNA hybridization (dDDH), respectively. MSKU 9T and MSKU 15 can be differentiated from the closely related K. swingsii JCM 17123T by their growth on 30 % d-glucose and ability to utilize and to form acid from raffinose and sucrose as carbon sources, and from K. europaeus DSM 6160T by their ability to grow without acetic acid. The genomic DNA G+C contents of MSKU 9T and MSKU 15 were 60.4 and 60.2 mol%, respectively. The major fatty acids of MSKU 9T and MSKU 15 were summed feature 8 (C18 : 1 ω7c and/or C18  : 1ω6c). The respiratory quinone was determined to be Q10. On the basis of the results of the polyphasic taxonomic analysis, MSKU 9T (=TBRC 9844T=NBRC 113802T) represents a novel species of the genus Komagataeibacter, for which the name Komagataeibacter diospyri sp. nov. is proposed.

Gluconobacter aidae sp. nov., an acetic acid bacterium isolated from tropical fruits in Thailand.

Two bacterial strains, isolates AC10T and AC20, which were reported in a previous study on the diversity of acetic acid bacteria in Thailand, were subjected to a taxonomic study. The phylogenetic analysis based on the 16S rRNA gene sequences showed that the two isolates were located closely to the type strains of Gluconobacter oxydans and Gluconobacter roseus. However, the two isolates formed a separate cluster from the type strains of the two species. The genomic DNA of isolate AC10T was sequenced. The assembled genomes of the isolate were analysed for average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH). The results showed that the highest ANI and dDDH values between isolate AC10T and G. oxydans DSM 3503T were 91.15 and 68.2 %, which are lower than the suggested values for species delineation. The genome-based tree was reconstructed and the phylogenetic lineage based on genome sequences showed that the lineage of isolate AC10T was distinct from G. oxydans DSM 3503T and its related species. The two isolates were distinguished from G. oxydans and their relatives by their phenotypic characteristics and MALDI-TOF profiles. Therefore, the two isolates, AC10T (=BCC 15749T=TBRC 11329T=NBRC 103576T) and AC20 (=BCC 15759=TBRC 11330=NBRC 103579), can be assigned to an independent species within the genus Gluconobacter, and the name Gluconobacter aidae sp. nov. is proposed for the two isolates.

Lactobacillus plajomi sp. nov. and Lactobacillus modestisalitolerans sp. nov., isolated from traditional fermented foods.

Three Lactobacillus-like strains, NB53T, NB446T and NB702, were isolated from traditional fermented food in Thailand. Comparative 16S rRNA gene sequence analysis indicated that these strains belong to the Lactobacillus plantarum group. Phylogenetic analysis based on the dnaK, rpoA, pheS and recA gene sequences indicated that these three strains were distantly related to known species present in the L. plantarum group. DNA-DNA hybridization with closely related strains demonstrated that these strains represented two novel species; the novel strains could be differentiated based on chemotaxonomic and phenotypic characteristics. Therefore, two novel species of the genus Lactobacillus, Lactobacillus plajomi sp. nov. (NB53T) and Lactobacillus modestisalitolerans sp. nov. (NB446T and NB702), are proposed with the type strains NB53T ( = NBRC 107333T = BCC 38054T) and NB446T ( = NBRC 107235T = BCC 38191T), respectively.

Endosaccharibacter trunci gen. nov., sp. nov. and Rhizosaccharibacter radicis gen. nov., sp. nov., two novel bacteria of the family Acetobacteraceae isolated from sugarcane.

Two novel endophytic bacterial strains, designated KSS8T and KSS12T, were isolated from the stems and roots of sugarcane, respectively, collected in Nakhon Ratchasima, Thailand. They were Gram-stain-negative, aerobic, and rod-shaped. The strain KSS8T was a motile bacterium with a subpolar flagellum, while the strain KSS12T was non-motile. Strains KSS8T and KSS12T were closely related to Lichenicola cladoniae PAMC 26569T (97.3 and 95.6 %, respectively) and Lichenicoccus roseus KEBCLARHB70RT (97.2 and 95.8 %, respectively) based on the similarity on their 16S rRNA gene sequence. This similarity corresponded to their phylogenomic positions within the evolutionary radiation of the family Acetobacteraceae. The average nucleotide identities and digital DNA-DNA hybridization values between the genome sequences of the two strains and other genera were significantly lower than the defined threshold values of 95-96 % and 70 %, respectively, which are used for the delineation of prokaryotic species. Both strains contained summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), C16:0, C19:0 cyclo ω8c, C18:0, and C18:1 2OH as the predominant cellular fatty acids, but C18:3 ω6c (6, 9, 12) were found only in strain KSS12T. Based on phenotypic, chemotaxonomic, phylogenetic, and genomic analyses, these strains clearly represented two novel genera within the family Acetobacteraceae, for which the name Endosaccharibacter gen. nov., with the type species Endosaccharibacter trunci sp. nov. (type strain, KSS8T = TBRC 14669T = NBRC 115232T = KCTC 92115T = LMG 32414T) and the name Rhizosacchari bacter gen. nov., with the type species Rhizosaccharibacter radicis sp. nov. (type strain, KSS12T = TBRC 13066T = NBRC 114898T = KCTC 82433T = LMG 32137T) are proposed.

Gluconobacter nephelii sp. nov., an acetic acid bacterium in the class Alphaproteobacteria.

Three strains, RBY-1(T), PHD-1 and PHD-2, were isolated from fruits in Thailand. The strains were Gram-negative, aerobic rods with polar flagella, produced acetic acid from ethanol and did not oxidize acetate or lactate. In phylogenetic trees based on 16S rRNA gene sequences and 16S-23S rRNA gene internal transcribed spacer (ITS) sequences, the strains formed a cluster separate from the type strains of recognized species of the genus Gluconobacter. The calculated 16S rRNA gene sequence and 16S-23S rRNA gene ITS sequence similarities were respectively 97.7-99.7 % and 77.3-98.1 %. DNA G+C contents ranged from 57.2 to 57.6 mol%. The strains showed high DNA-DNA relatedness of 100 % to one another, but low DNA-DNA relatedness of 11-34 % to the tested type strains of recognized Gluconobacter species. Q-10 was the major quinone. On the basis of the genotypic and phenotypic data obtained, the three strains clearly represent a novel species, for which the name Gluconobacter nephelii sp. nov. is proposed. The type strain is RBY-1(T) ( = BCC 36733(T) = NBRC 106061(T) = PCU 318(T)), whose DNA G+C content is 57.2 mol%.

Neokomagataea gen. nov., with descriptions of Neokomagataea thailandica sp. nov. and Neokomagataea tanensis sp. nov., osmotolerant acetic acid bacteria of the α-Proteobacteria.

Isolates AH11(T) and AH13(T) were isolated from flowers of lantana and candle bush respectively collected in Thailand. In phylogenetic trees based on 16S rRNA gene sequences, the two isolates formed an independent cluster, which was then connected to the type strain of Saccharibacter floricola. The calculated pair-wise 16S rRNA gene sequence similarities of isolate AH11(T) were 95.7-92.3% to the type strains of the type species of the 12 genera of acetic acid bacteria. The DNA base composition was from 51.2 to 56.8 mol % G+C, with a range of 5.6 mol %. When isolate AH11(T) was labeled, DNA-DNA similarities were 100, 12, 4, 5, and 4% respectively to isolates AH11(T) and AH13(T) and the type strains of Saccharibacter floricola, Gluconobacter oxydans, and Acetobacter aceti. The two isolates were non-motile and did not oxidize either acetate or lactate. No growth was found in the presence of 0.35% acetic acid w/v. The two isolates were not osmophilic but osmotolerant, produced 2,5-diketo-D-gluconate from D-glucose, and did not oxidize lactate, thus differing from strains of Saccharibacter floricola, which showed weak lactate oxidation. The two isolates contained unsaturated C(18:1)ω7c fatty acid as the major fatty acid, and were unique in the presence of a considerable amount of straight-chain C(18:1)2OH fatty acid. Q-10 was present as the major isoprenoid quinone. Neokomagataea gen. nov. was proposed with the two species, Neokomagataea thailandica sp. nov. for isolate AH11(T) (=BCC 25710(T)=NBRC 106555(T)), which has 56.8 mol % G+C, and Neokomagataea tanensis sp. nov. for isolate AH13(T) (=BCC 25711(T)=NBRC 106556(T)), which has 51.2 mol % G+C.

Identification of Acetobacter strains from Thai fermented rice products based on the 16S rRNA gene sequence and 16S-23S rRNA gene internal transcribed spacer restriction analyses.

BACKGROUND: Fermented rice flour (khao-khab, a non-glutinous rice) and related products are Thai traditional products. The types of acetic acid bacteria (AAB) microflora in khao-khab have not been reported. In this study, Acetobacter strains were isolated and identified based on the phenotypic and chemotaxonomic characteristics and molecular aspects. RESULTS: Twenty-five acetic acid bacteria isolated from fermented rice products and a starter for sweetened rice in Thailand by an enrichment culture approach, were assigned to the genus Acetobacter by phenotypic and chemotaxonomic characterisations. On the basis of the 16S rRNA gene sequence and 16S-23S rRNA gene ITS restriction analyses, 25 isolates were divided into six groups and identified at the specific level: (1) Group 1 included five isolates, which were identified as A. indonesiensis; (2) Group 2 included two isolates, which were identified as A. lovaniensis; (3) Group 3 included one isolate, which was identified as A. orientalis; (4) Group 4 included eleven isolates, which were identified as A. pasteurianus; (5) Group 5 included three isolates, which were identified as A. syzygii and (6) Group 6 included three isolates, which were unidentified and considered to constitute a new species. CONCLUSION: Results revealed that various Acetobacter species were distributed in Thai fermented rice flour and related products. A novel Acetobacter species was isolated from the product.

Production of 4-keto-D-arabonate by oxidative fermentation with newly isolated Gluconacetobacter liquefaciens.

Production of 4-keto-D-arabonate (4KAB) was confirmed in a culture medium of Gluconacetobacter liquefaciens strains, newly isolated from water kefir in Argentina. The strains rapidly oxidized D-glucose, D-gluconate (GA), and 2-keto-D-gluconate (2KGA), and accumulated 2,5-diketo-D-gluconate (25DKA) exclusively before reaching the stationary phase. 25DKA was in turn converted to 4KAB, and 4KAB remained stable in the culture medium. The occurrence of 4KAB was assumed by Ameyama and Kondo about 50 years ago in their study on the carbohydrate metabolism of acetic acid bacteria (Bull. Agr. Chem. Soc. Jpn., 22, 271-272, 380-386 (1958)). This is the first report confirming microbial production of 4KAB.

Ameyamaea chiangmaiensis gen. nov., sp. nov., an acetic acid bacterium in the alpha-Proteobacteria.

Two isolates, AC04(T) and AC05, were isolated from the flowers of red ginger collected in Chiang Mai, Thailand. In phylogenetic trees based on 16S rRNA gene sequences, the two isolates were included within a lineage comprised of the genera Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Neoasaia, Granulibacter, and Tanticharoenia, and they formed an independent cluster along with the type strain of Tanticharoenia sakaeratensis. The calculated pair-wise sequence similarities of isolate AC04(T) were 97.8-92.5% to the type strains of the type species of the 11 genera of acetic acid bacteria. The DNA base composition was 66.0-66.1 mol % G+C with a range of 0.1 mol %. A single-stranded, labeled DNA from isolate AC04(T) presented levels of DNA-DNA hybridization of 100, 85, 4, and 3% respectively to DNAs from isolates AC04(T) and AC05 and the type strains of Tanticharoenia sakaeratensis and Gluconacetobacter liquefaciens. The two isolates were unique morphologically in polar flagellation and physiologically in intense acetate oxidation to carbon dioxide and water and weak lactate oxidation. The intensity in acetate oxidation almost equaled that of the type strain of Acetobacter aceti. The two isolates had Q-10. Isolate AC04(T) was discriminated from the type strains of the type species of the 11 genera by 16S rRNA gene restriction analysis using restriction endonucleases TaqI and Hin6I. The unique phylogenetic, genetic, morphological, physiological, and biochemical characteristics obtained indicate that the two isolates can be classified into a separate genus, and Ameyamaea chiangmaiensis gen. nov., sp. nov. is proposed. The type strain is isolate AC04(T) (=BCC 15744(T), =NBRC 103196(T)), which has a DNA G+C content of 66.0 mol %.

Genera and species in acetic acid bacteria.

Taxonomic studies of acetic acid bacteria were historically surveyed. The genus Acetobacter was first introduced in 1898 with a single species, Acetobacter aceti. The genus Gluconobacter was proposed in 1935 for strains with intense oxidation of glucose to gluconic acid rather than oxidation of ethanol to acetic acid and no oxidation of acetate. The genus "Acetomonas" was described in 1954 for strains with polar flagellation and no oxidation of acetate. The proposals of the two generic names were due to confusion, and "Acetomonas" was a junior subjective synonym of Gluconobacter. The genus Acetobacter was in 1984 divided into two subgenera, Acetobacter and Gluconoacetobacter. The latter was elevated to the genus Gluconacetobacter in 1998. In the acetic acid bacteria, ten genera are presently recognized and accommodated to the family Acetobacteraceae, the Alphaproteobacteria: Acetobacteer, Gluconobacter, Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia and Granulibacter. In contrast, the genus Frateuria, strains of which were once named 'pseudacetic acid bacteria', was classified into the Gammaproteobacteria. The genus Gluconacetobacter was phylogenetically divided into two groups: the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group. The two groups were discussed taxonomically.

Asaia lannaensis sp. nov., a new acetic acid bacterium in the Alphaproteobacteria.

Asaia lannaensis sp. nov. was described for two strains isolated from flowers of the spider lily collected in Chiang Mai, Thailand. The isolates produced acetic acid from ethanol on ethanol/calcium carbonate agar, differing from the type strains of Asaia bogorensis, Asaia siamensis, and Asaia krungthepensis, but did not grow in the presence of 0.35% acetic acid (v/v). The new species is the fourth of the genus Asaia, the family Acetobacteraceae.

Tanticharoenia sakaeratensis gen. nov., sp. nov., a new osmotolerant acetic acid bacterium in the alpha-Proteobacteria.

Tanticharoenia sakaeratensis gen. nov., sp. nov. is proposed for three strains isolated from soil collected in Thailand. The three strains, AC37(T), AC38, and AC39, were included within a lineage comprising the genera Asaia, Kozakia, Swaminathania, Neoasaia, Acetobacter, Gluconobacter, and Saccharibacter in a phylogenetic tree based on 16S rRNA gene sequences, but formed a quite different, independent cluster. Pair-wise sequence similarities of strain AC37(T) were 96.5-92.1% to the type strains of Acetobacter aceti, Gluconobacter oxydans, Acidomonas methanolica, Gluconacetobacter liquefaciens, Asaia bogorensis, Kozakia baliensis, Swaminathania salitolerans, Saccharibacter floricola, Neoasaia chiangmaiensis, and Granulibacter bethesdensis. The three strains had DNA base compositions comprising respectively 65.6, 64.5, and 65.6 mol % G+C with a range of 1.1 mol %, and formed a single species. Phenotypically, the three strains did not oxidize acetate or lactate, but grew on 30% D-glucose (w/v). Chemotaxonomically, they had Q-10. The type strain is AC37(T) (= BCC 15772(T) = NBRC 103193(T)).