- Volume 67, Issue 4, 2017

A Gram-stain-negative, oxidase-negative, catalase-positive, facultative anaerobe, designated XJ16T, was isolated from a marine solar saltern on the coast of Weihai, China. Cells of strain XJ16T were long and rod-shaped. The colonies were ochre in colour and were able to reduce nitrate to nitrite. Optimal growth occurred at 33–37 °C (range, 20–45 °C) and in the presence of 8–10 % (w/v) NaCl (range, 2–20 %). The pH range for growth was found to be 6.5–9.5, with optimum growth at pH 7.5–8.0. Phylogenetic analysis based on the 16S rRNA gene sequence demonstrated that strain XJ16T was related to the phylum Proteobacteria . The most closely related neighbours were species of the genus Thioalkalivibrio , and the 16S rRNA gene sequence of strain XJ16T shared 93.1 % similarity with that of Thioalkalivibrio sulfidiphilus HL-EbGr7T and 93.0 % similarity with that of Thioalkalivibrio denitrificans ALJDT. The G+C content of the genomic DNA was 65.9 mol% (HPLC). The sole respiratory quinone was Q-8, and the predominant cellular fatty acids (>10 %) were iso-C15 : 0 2-OH/C16 : 1ω7c, C18 : 0 and C16 : 0 10-CH3. The predominant polar lipids in strain XJ16T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. Based on these phylogenetic, physiological and biochemical characteristics, strain XJ16T should be classified representing a novel species of a new genus within the family Ectothiorhodospiraceae , for which the name Halofilum ochraceum gen. nov., sp. nov. is proposed. The type strain of the type species is XJ16T (=KCTC 42259T=MCCC 1H00120T=CICC 23817T).

A Gram-stain-negative, rod-shaped, motile bacterium, designated AER10T, was isolated from the roots of Ammodendron bifolium collected from Takeermohuer desert in Xinjiang Uygur Autonomous Region, northwestern China. Growth was found to occur from 10 to 45 °C, at pH 5.0–9.0, and could tolerate up to 10 % (w/v) NaCl. 16S rRNA gene sequence result indicated that the strain AER10T belongs to the genus Alcaligenes and was closely related to Alcaligenes aquatilis (98.4 %), Alcaligenes faecalis subsp. parafaecalis (98.4 %), Alcaligenes faecalis subsp. faecalis (98.1 %) and Alcaligenes faecalis subsp. phenolicus (97.9 %). However, the DNA–DNA hybridization values between the strain AER10T and the above strains were less than the threshold value (below 70 %) for the delineation of genomic species. The DNA G+C content was 53.3 mol%. Ubiquinone-8 (Q-8) was the only quinone system present. The major fatty acids were summed feature 8 (C18 : 1ω7c, 25 %), C16 : 0 (24.2 %), summed feature 3 (C16 : 1ω7c and/or C16  : 1ω6c, 19.3 %) and cyclo-C17 : 0 (10.5 %). The polar lipid profile of the strain AER10T consists of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, two unidentified aminolipids and five unknown polar lipids. On the basis of the evidence presented in this study, strain AER10T is a representative of a novel species in the genus Alcaligenes , for which the name Alcaligenes endophyticus sp. nov. is proposed. The type strain is AER10T (=DSM 100498T=KCTC 42688T).

Two Gram-stain-negative, aerobic, rod-shaped endophytic bacterial strains, N19T and N11-2, were isolated from fresh rice (Oryza sativa) roots during investigation of the rice endophytic bacterial diversity. The 16S rRNA gene sequence results indicated that the similarity between strains N19T and N11-2 was 100 %. Both of them belong to the genus Rhizobium , with close similarity to Rhizobium taibaishanense CCNWSX 0483T (97.7 %), followed by Rhizobium vitis NCPPB 3554T (97.5 %). The sequence similarities of the housekeeping genes recA, gyrB and glnA between the novel isolates and members of the established species of the genus Rhizobium were less than 87 %. The DNA–DNA hybridization rates between strains N19T and N11-2 were 87.9 % using the initial renaturation rate method. Based on draft genome sequences, strain N19T showed 18.2 % and 19.6 % DNA–DNA hybridization values to R. taibaishanense CCNWSX 0483T and R. vitis S4, which demonstrated that these new isolates represent a novel species in the genus Rhizobium . The main cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The DNA G+C content of strain N19T was 58.7 mol% (T m). The polar lipid profile of N19T consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unknown lipid, two unknown aminolipids and an unidentified aminophospholipid. According to physiological and biochemical characteristics and genotypic data, strains N19T and N11-2 are considered to represent a novel species of the genus Rhizobium , for which the name Rhizobium oryziradicis sp. nov. is proposed, with N19T (=ACCC 19962T=KCTC 52413T) as the type strain.

A bacterial strain designated GTAE24T was isolated from a root of wheat growing in soil from the Canary Islands, Spain. Phylogenetic analyses based on 16S rRNA gene sequences placed the isolate in the genus Brevundimonas with Brevundimonas abyssalis TAR-001T as its closest relative at 99.4 % similarity. DNA–DNA hybridization studies showed an average of 38 % relatedness between strain GTAE24T and the type strain of B. abyssalis . Cells were Gram-stain-negative and motile by polar flagella. The strain was positive for oxidase and weakly positive for catalase. Gelatin, starch and casein were not hydrolysed. Growth was supported by many carbohydrates and organic acids as carbon source. Ubiquinone Q-10 was the predominant isoprenoid quinone and C18 : 1ω7c/C18  : 1ω6c (summed feature 8) and C16 : 0 were the major fatty acids. The major polar lipids were phosphatidylglycerol, 1,2-di-O -acyl-3-O-[d-glucopyranosyl-(1,4)-α-d-glucopyranuronosyl] glycerol, 1,2-diacyl-3-O-[6′-phosphatidyl-α-d-glucopyranosyl] glycerol, 1,2-di-O-acyl-3-O-α-d-glucopyranosyl glycerol, and 1,2-di-O-acyl-3-O-α-d-glucopyranuronosyl glycerol. The DNA G+C content was 63.9 mol%. Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain GTAE24T should be considered as representing a novel species of the genus Brevundimonas , for which the name Brevundimonas canariensis sp. nov. is proposed. The type strain is GTAE24T (=LMG 29500T=CECT 9126T).

A bacterial strain designated K7T was isolated from the South China Sea and characterized using a polyphasic taxonomic approach. Cells of strain K7T were Gram-stain-negative, aerobic, poly-β-hydroxybutyrate-accumulating, motile by means of a monopolar flagellum, non-spore forming rods surrounded by a thick capsule and forming yellow colonies. Growth occurred at 4–35 °C (optimum, 25–30 °C), at pH 5.0–9.0 (optimum, pH 7.0) and with 0.5–10 % (w/v) NaCl [optimum, 1–4 % (w/v)]. The predominant fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c. The major isoprenoid quinone was Q-8 and the DNA G+C content was 46.5 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmonomethylethanolamine, one uncharacterized phospholipid, two uncharacterized aminophospholipids and five uncharacterized lipids. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain K7T formed a distinct lineage with respect to closely related genera in the family Alteromonadaceae . Strain K7T was most closely related to Aestuariibacter , Aliiglaciecola , Paraglaciecola and Glaciecola , and the levels of 16S rRNA gene sequence similarity with respect to the type species of related genera were less than 95 %. On the basis of the genotypic and phenotypic data, strain K7T represents a novel species of a new genus of the family Alteromonadaceae , for which the name Planctobacterium marinum gen. nov., sp. nov. is proposed. The type strain of Planctobacterium marinum is K7T (=BCRC 80901T=LMG 28835T=KCTC 42657T).

A wine-red-coloured, Gram-stain-negative, aerobic, non-motile and coccus-shaped bacterium, designated strain G-3-5T, was isolated from oil-contaminated soil of Biratnagar, Morang, Nepal, during a study of oil-utilizing bacteria. This strain was catalase-negative and oxidase-positive. It was able to grow at 10–37 °C, at pH 6.0–10.0 and with 0.02–1.02 % (w/v) NaCl. This strain was taxonomically characterized by a polyphasic approach. Based on 16S rRNA gene sequence analysis, strain G-3-5T belongs to the genus Roseomonas and is closely related to Roseomonas vinacea CPCC 100056T (97.81 % sequence similarity), Roseomonas aerilata 5420S-30T (96.68 %), Roseomonas pecuniae N75T (96.15 %), ‘ Roseomonas aceris ’ R-1 (95.75 %) and Roseomonas rosea 173/96T (95.30 %). The only respiratory quinone was ubiquinone-10. The polar lipid profile revealed the presence of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The major fatty acids of strain G-3-5T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0, C18 : 0 and C18 : 1 2-OH. The genomic DNA G+C content of this novel strain was 68.3 mol%. The DNA–DNA relatedness between strain G-3-5T and Roseomonas. vinacea KACC 13934T was 26.3 %. The morphological, physiological, chemotaxonomic and phylogenetic analyses clearly distinguished this strain from its closest phylogenetic neighbours. Thus, strain G-3-5T represents a novel species of the genus Roseomonas , for which the name Roseomonas nepalensis sp. nov. is proposed. The type strain is G-3-5T (=KEMB 9005-416T=KACC 18908T=JCM 31470T).

A novel bacterium, designated as strain AM134T, was isolated from the gut of a purple sea urchin (Heliocidaris crassispina) gathered from the coastal waters of Dokdo, Korea. Strain AM134T was Gram-stain-negative, both catalase- and oxidase-positive, strictly aerobic and showed a rod-coccus cell cycle. Optimum growth occurred at 30 °C, in the presence of 2 % (w/v) NaCl and at pH 7. The 16S rRNA gene sequence analysis showed that strain AM134T belonged to the genus Microbulbifer in the family Alteromonadaceae and had high 16S rRNA gene sequence similarity (>97 %) with Microbulbifer epialgicus F-104T (98.9 % similarity) and Microbulbifer variabilis Ni-2088T (98.6 % similarity). The polar lipid profile of strain AM134T was composed of phosphatidylethanolamine, phosphatidylserine, three unidentified aminophospholipids, two unidentified phospholipids, an unidentified amino lipid and six unidentified lipids. The major respiratory quinone was identified as ubiquinone-8 (Q-8). The major cellular fatty acids were summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c) and C16 : 0. The DNA–DNA hybridization analysis showed that the strain shared less than 28 % genomic relatedness with Microbulbifer epialgicus DSM 18651T (27±3 %) and Microbulbifer variabilis ATCC 700307T (15±1 %). The G+C content of the genomic DNA was 56.1 mol%. The results of the phylogenetic, phenotypic and genotypic analyses suggest that strain AM134T represents a novel species in the genus Microbulbifer , for which the name Microbulbifer echini is proposed. The type strain is AM134T (=KACC 18258T=JCM 30400T).

A Gram-reaction-negative, rod-shaped, facultatively anaerobic, motile bacterium, designated strain AR1T, was isolated from a freshwater stream in Jeonju, South Korea. Strain AR1T showed highest 16S rRNA gene sequence similarity (96.83 %) and also formed a separate clade with Aeromonas sharmana GPTSA-6T in the phylogenetic tree reconstructed among the members of the family Aeromonadaceae . Major cellular fatty acids are summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) and C16: 0. Diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol are the predominant polar lipids. The genomic DNA G+C content was found to be 54.7 mol%. However, earlier studies on 16S rRNA gene, gyrB, rpoD and universal target region of cpn60 sequences of the members of the genus Aeromonas recommended the transfer of Aeromonas sharmana to a new genus. Hence, based on the comparative polyphasic data obtained during the present study and also on the previous recommendations, it is proposed that Aeromonas sharmana be transferred to a novel genus as Pseudaeromonas sharmana gen. nov., comb. nov. with strain GPTSA-6T (=DSM 17445T=MTCC 7090T=CIP 109378T=CCUG 54939T) as the type strain of the type species of the genus. Also, it is proposed that strain AR1T be designated as a representative of a novel species of this new genus, namely Pseudaeromonas pectinilytica sp. nov. The type strain is AR1T (=KCTC 42754T=JCM 31503T).

A novel alphaproteobacterium was isolated from the well water of a thermal bath at Budapest, Hungary. Phylogenetic analysis of the novel strain showed that this bacterium belongs to a distinct lineage among the genus Brevundimonas . Based on the 16S rRNA gene sequence strain FDRGB2bT showed the highest sequence similarity values to Brevundimonas naejangsanensis BIO-TAS2-2T (97.35 %), Brevundimonas viscosa F3T (97.28 %), Brevundimonas vesicularis LMG 2350T (97.27 %), Brevundimonas nasdae GTC 1043T (97.14 %), Brevundimonas vancanneytii LMG 2337T (97.13 %) and Brevundimonas aurantiaca DSM 4731T (97.13 %). The newly isolated bacterium was strictly aerobic, and its optimum growth occurred at 20–30 °C, between pH 8–9 and without NaCl. Movement was with a single polar flagellum, but the cells could also produce stalks. The major isoprenoid quinone of strain FDRGB2bT was Q-10, the major cellular fatty acids were C18 : 1ω7c and C16 : 0, and the polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol, two unknown phospholipids and four unknown glycolipids. The characteristic diamino acid in its cell wall is meso-diaminopimelic acid. The G+C content of DNA of the type strain was 69.8 mol%. Strain FDRGB2bT (=DSM 29841T=NCAIM B.02621T) is proposed as the type strain of a novel species with the proposed name Brevundimonas balnearis sp. nov.

A lightly yellowish-pigmented, oxidase-negative bacterial strain (PB45.5T) isolated from the Nam Nao district of Phetchabun in central Thailand was investigated to determine its taxonomic position. Cells of the isolate showed a rod shaped appearance. The strain stained Gram-negative. Strain PB45.5T shared highest 16S rRNA gene sequence similarity with the type strains of Photorhabdus luminescens subsp. akhurstii (99.2 %) and Photorhabdus luminescens subsp. hainanensis (99.1 %) and lower similarities to all other Photorhabdus luminescens subspecies (<98.0 %). Multilocus sequence analysis (MLSA) based on concatenated partial recA, dnaN, gltX, gyrB and infB gene sequences confirmed the affiliation obtained by 16S rRNA gene sequence analysis but showed a clear distinction of PB45.5T from the closest related type strains. Strain PB45.5T shared only 96.9 % sequence similarity (concatenated nucleotide sequences) with P. luminescens subsp. akhurstii FRG04T and 96.8 % with P. luminescens subsp. hainanensis C8404T. The fatty acid profile of the strain consisted of the major fatty acids C14 : 0, C16 : 0, C17 : 0 cyclo, C16 : 1ω7c and/or iso-C15 : 0 2-OH, and C18 : 1 ω7c. The MLSA results and the differential biochemical and chemotaxonomic properties showed that strain PB45.5T represents a novel P. luminescens subspecies, for which the name Photorhabdus luminescens subsp. namnaonensis subsp. nov. (type strain PB45.5T=LMG 29915T=CCM 8729T) is proposed.

One hundred and ninety-eight isolates of soil yeasts were isolated from mixed temperate forests in the Czech Republic, and their abundance and distribution in the litter and soil were evaluated using amplicon sequencing of soil fungal communities. Abundant taxa with no close identified hits were selected for further characterization as potential novel species of yeasts. Phylogenetic analyses using sequences of the D1/D2 domain, the ITS region and RPB1 and TEF1 genes support the recognition of the following three novel species belonging to the subphylum Pucciniomycotina, class Microbotryomycetes: Leucosporidium krtinense f.a. sp. nov. (type strain PYCC 6879T=KT96T=CBS 14304T=DSM 101892T), Yurkovia mendeliana sp. nov. (type strain PYCC 6884T=KT152T=CBS 14273T=DSM 101889T) and Libkindia masarykiana sp. nov. (type strain PYCC 6886T=KT310T=CBS 14275T=DSM 101891T). Since the latter two novel taxa cannot be assigned to existing genera, two new genera, Libkindia gen. nov. and Yurkovia gen. nov., are also described.

Three strains (14Y260T, 14Y268 and 14Y276) of xylose-assimilating yeasts were isolated from decayed wood and soil collected in West Java in Indonesia. A phylogenetic analysis was performed based on the sequences of the D1/D2 domains of LSU, SSU and EF-1α, and the three strains were found to belong to the genus Pichia. The morphological, biochemical, physiological and chemotaxonomic characteristics indicated that these strains were distinct from other closely related species. Strains 14Y260T, 14Y268 and 14Y276 belonged to the Pichia clade and represent a novel species, named Pichia chibodasensis sp. nov. ; The type strain is 14Y260T (=NBRC 111569T=InaCC Y1042T).

A novel basidiomycetous yeast was isolated from the waste deposit of the attine ant Acromyrmex lundii (Hymenoptera: Formicidae). The field colony was located in Santurce town, Santa Fe province, Argentina. The description of the novel species was based on strain LLU043T. Analysis of the D1/D2 domains of the LSU rRNA gene sequences in GenBank demonstrated that strain LLU043T, belongs to the Rhodosporidiobolus clade and is closely related to Rhodosporidiobolus lusitaniae and Rhodosporidiobolus colostri with 97 % similarity to the two species. The novel species differs from R . lusitaniae and R. colostri in some physiological characteristics such as the lack of assimilation of cellobiose, salicin, succinate, citrate and ethylamine. The name Rhodosporidiobolus geoffroeae sp. nov. is proposed, with LLU043T (=CBS 12828T=CBMAI 1618T) as the type strain.

While all names of new taxa submitted to the International Journal of Systematic and Evolutionary Microbiology, either in direct submissions or in validation requests for names effectively published elsewhere, are subject to nomenclatural review to ensure that they are acceptable based on the rules of the International Code of Nomenclature of Prokaryotes, the names of Candidatus taxa have not been subjected to such a review. Formally, this was not necessary because the rank of Candidatus is not covered by the Code, and the names lack the priority afforded validly published names. However, many Candidatus taxa of different ranks are widely discussed in the scientific literature, and a proposal to incorporate the nomenclature of uncultured prokaryotes under the provisions of the Code is currently pending. Therefore, an evaluation of the names of Candidatus taxa published thus far is very timely. Out of the ~400 Candidatus names found in the literature, 120 contradict the current rules of the Code or are otherwise problematic. A list of those names of Candidatus taxa that need correction is presented here and alternative names that agree with the provisions of the Code are proposed.