scholarly journals Genome-based taxonomic framework for the class Negativicutes: division of the class Negativicutes into the orders Selenomonadales emend., Acidaminococcales ord. nov. and Veillonellales ord. nov.

2015 ◽  
Vol 65 (Pt_9) ◽  
pp. 3203-3215 ◽  
Author(s):  
Chantal Campbell ◽  
Mobolaji Adeolu ◽  
Radhey S. Gupta

The class Negativicutes is currently divided into one order and two families on the basis of 16S rRNA gene sequence phylogenies. We report here comprehensive comparative genomic analyses of the sequenced members of the class Negativicutes to demarcate its different evolutionary groups in molecular terms, independently of phylogenetic trees. Our comparative genomic analyses have identified 14 conserved signature indels (CSIs) and 48 conserved signature proteins (CSPs) that either are specific for the entire class or differentiate four main groups within the class. Two CSIs and nine CSPs are shared uniquely by all or most members of the class Negativicutes, distinguishing this class from all other sequenced members of the phylum Firmicutes. Four other CSIs and six CSPs were specific characteristics of the family Acidaminococcaceae, two CSIs and four CSPs were uniquely present in the family Veillonellaceae, six CSIs and eight CSPs were found only in Selenomonas and related genera, and 17 CSPs were identified uniquely in Sporomusa and related genera. Four additional CSPs support a pairing of the groups containing the genera Selenomonas and Sporomusa. We also report detailed phylogenetic analyses for the Negativicutes based on core protein sequences and 16S rRNA gene sequences, which strongly support the four main groups identified by CSIs and by CSPs. Based on the results from different lines of investigation, we propose a division of the class Negativicutes into an emended order Selenomonadales containing the new families Selenomonadaceae fam. nov. and Sporomusaceae fam. nov. and two new orders, Acidaminococcales ord. nov. and Veillonellales ord. nov., respectively containing the families Acidaminococcaceae and Veillonellaceae.

2007 ◽  
Vol 57 (10) ◽  
pp. 2289-2295 ◽  
Author(s):  
Madalin Enache ◽  
Takashi Itoh ◽  
Tadamasa Fukushima ◽  
Ron Usami ◽  
Lucia Dumitru ◽  
...  

In order to clarify the current phylogeny of the haloarchaea, particularly the closely related genera that have been difficult to sort out using 16S rRNA gene sequences, the DNA-dependent RNA polymerase subunit B′ gene (rpoB′) was used as a complementary molecular marker. Partial sequences of the gene were determined from 16 strains of the family Halobacteriaceae. Comparisons of phylogenetic trees inferred from the gene and protein sequences as well as from corresponding 16S rRNA gene sequences suggested that species of the genera Natrialba, Natronococcus, Halobiforma, Natronobacterium, Natronorubrum, Natrinema/Haloterrigena and Natronolimnobius formed a monophyletic group in all trees. In the RpoB′ protein tree, the alkaliphilic species Natrialba chahannaoensis, Natrialba hulunbeirensis and Natrialba magadii formed a tight group, while the neutrophilic species Natrialba asiatica formed a separate group with species of the genera Natronorubrum and Natronolimnobius. Species of the genus Natronorubrum were split into two groups in both the rpoB′ gene and protein trees. The most important advantage of the use of the rpoB′ gene over the 16S rRNA gene is that sequences of the former are highly conserved amongst species of the family Halobacteriaceae. All sequences determined so far can be aligned unambiguously without any gaps. On the other hand, gaps are necessary at 49 positions in the inner part of the alignment of 16S rRNA gene sequences. The rpoB′ gene and protein sequences can be used as an excellent alternative molecular marker in phylogenetic analysis of the Halobacteriaceae.


2012 ◽  
Vol 62 (Pt_9) ◽  
pp. 2163-2168 ◽  
Author(s):  
Yong-Taek Jung ◽  
Ji-Hoon Kim ◽  
So-Jung Kang ◽  
Tae-Kwang Oh ◽  
Jung-Hoon Yoon

A Gram-staining-negative, non-flagellated, non-gliding and pleomorphic bacterial strain, designated DPG-25T, was isolated from seawater in a seaweed farm in the South Sea in Korea and its taxonomic position was investigated by using a polyphasic approach. Strain DPG-25T grew optimally at 25 °C, at pH 7.0–7.5 and in the presence of 2 % (w/v) NaCl. Flexirubin-type pigments were not produced. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain DPG-25T formed a cluster with the type strains of Actibacter sediminis , Aestuariicola saemankumensis and Lutimonas vermicola . Strain DPG-25T exhibited 16S rRNA gene sequence similarity values of 95.3, 93.1 and 93.6 % to the type strains of Actibacter sediminis , Aestuariicola saemankumensis and L. vermicola , respectively. Strain DPG-25T contained MK-6 as the predominant menaquinone and iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipids detected in strain DPG-25T were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content was 39.9 mol%. Differential phenotypic properties and the phylogenetic distinctiveness of strain DPG-25T demonstrated that this strain is distinguishable from Actibacter sediminis , Aestuariicola saemankumensis and L. vermicola . On the basis of the data presented here, strain DPG-25T represents a novel species in a novel genus of the family Flavobacteriaceae , for which the name Namhaeicola litoreus gen. nov., sp. nov. is proposed. The type strain of Namhaeicola litoreus is DPG-25T ( = KCTC 23702T  = CCUG 61485T).


2007 ◽  
Vol 57 (1) ◽  
pp. 141-145 ◽  
Author(s):  
Zhe-Xue Quan ◽  
Kwang Kyu Kim ◽  
Myung-Kyum Kim ◽  
Long Jin ◽  
Sung-Taik Lee

A Gram-negative, non-spore-forming, yellow-pigmented bacterium, strain N4T, was isolated from a nickel-complexed cyanide-degrading bioreactor and subjected to a polyphasic taxonomic study. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain N4T is affiliated to the genus Chryseobacterium of the family Flavobacteriaceae. The levels of 16S rRNA gene sequence similarity between strain N4T and the type strains of all known Chryseobacterium species were 93.2–95.8 %, suggesting that strain N4T represents a novel species within the genus Chryseobacterium. The strain contained iso-C15 : 0 and summed feature 4 as the major fatty acids and menaquinone MK-6 as the predominant respiratory quinone. The G+C content of the genomic DNA was 38.2 mol%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain N4T represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium caeni sp. nov. is proposed. The type strain is N4T (=KCTC 12506T=CCBAU 10201T=DSM 17710T).


2012 ◽  
Vol 62 (Pt_3) ◽  
pp. 539-544 ◽  
Author(s):  
Yong-Taek Jung ◽  
Ji-Hoon Kim ◽  
Tae-Kwang Oh ◽  
Jung-Hoon Yoon

A Gram-staining-negative, non-flagellated, non-gliding and rod-shaped bacterial strain, designated HWR-17T, was isolated from seawater of the Yellow Sea in Korea. Strain HWR-17T grew optimally at pH 7.0–8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HWR-17T clustered with the two Mariniflexile species in the family Flavobacteriaceae, exhibiting 16S rRNA gene sequence similarity of 97.1–97.2 % to their type strains and less than 95.7 % sequence similarity to other members of the family Flavobacteriaceae. Strain HWR-17T contained MK-6 as the predominant menaquinone and iso-C15 : 0 as the major fatty acid. The polar lipid profile of strain HWR-17T contained phosphatidylethanolamine, an unidentified aminolipid and four unidentified lipids. The DNA G+C content of strain HWR-17T was 35.7 mol% and it exhibited 11 and 10 % DNA–DNA relatedness, respectively, with Mariniflexile gromovii KCTC 12570T and Mariniflexile fucanivorans DSM 18792T. The phylogenetic and genetic distinctiveness and differential phenotypic properties revealed that strain HWR-17T is distinguishable from the two recognized Mariniflexile species. On the basis of the data presented, strain HWR-17T is considered to represent a novel species of the genus Mariniflexile, for which the name Mariniflexile aquimaris sp. nov. is proposed. The type strain is HWR-17T ( = KCTC 23346T  = CCUG 60529T). An emended description of the genus Mariniflexile is also proposed.


2010 ◽  
Vol 60 (9) ◽  
pp. 2023-2026 ◽  
Author(s):  
Shu-Juan Cao ◽  
Chun-Ping Deng ◽  
Bao-Zhen Li ◽  
Xiu-Qin Dong ◽  
Hong-Li Yuan

A Gram-negative, yellow-pigmented bacterium, designated strain R2A-16T, was isolated from sediment of Rupa Lake in Nepal and analysed using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain R2A-16T is affiliated to the genus Cloacibacterium of the family Flavobacteriaceae; 16S rRNA gene sequence similarity between strain R2A-16T and Cloacibacterium normanense CCUG 46293T was 98.07 %. The isolate contained iso-C15 : 0 (35.6 %) as the major fatty acid and menaquinone MK-6 as the predominant respiratory quinone. The G+C content of the genomic DNA was 33.3 mol%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain R2A-16T represents a novel species of the genus Cloacibacterium, for which the name Cloacibacterium rupense sp. nov. is proposed; the type strain is R2A-16T (=CGMCC 1.7656T =NBRC 104931T).


2007 ◽  
Vol 57 (7) ◽  
pp. 1572-1575 ◽  
Author(s):  
Hang-Yeon Weon ◽  
Byung-Yong Kim ◽  
Seung-Hee Yoo ◽  
Jae-Ho Joa ◽  
Soon-Wo Kwon ◽  
...  

A motile, Gram-negative, rod-shaped bacterium, designated strain JS11-7T, was isolated from forest soil from Halla Mountain, Jeju Island, Korea. It grew optimally at 28 °C, pH 6–7 and in the presence of 0–2 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain JS11-7T belongs to the family Neisseriaceae, with Silvimonas terrae as its closest relative (95.0 % similarity). It contained Q-8 as the predominant quinone and summed feature 3 (comprising iso-C15 : 0 2-OH and/or C16 : 1 ω6c), C16 : 0 and C18 : 1 ω7c as the major fatty acids. The DNA G+C content was 62 mol%. On the basis of phenotypic and genotypic characteristics and the results of 16S rRNA gene sequence analysis, strain JS11-7T represents a novel genus and species, for which the name Andreprevotia chitinilytica gen. nov., sp. nov. is proposed. The type species is Andreprevotia chitinilytica and the type strain is JS11-7T (=KACC 11608T=DSM 18519T).


2007 ◽  
Vol 57 (2) ◽  
pp. 270-275 ◽  
Author(s):  
Dong H. Choi ◽  
Jang-Cheon Cho ◽  
Brian D. Lanoil ◽  
Stephen J. Giovannoni ◽  
Byung C. Cho

Two strictly aerobic, Gram-negative bacteria, designated strains CL-SP27T and B5-6T, were isolated from the hypersaline water of a solar saltern in Korea and from the surface water of the Sargasso Sea, respectively. The two strains were rod-shaped, non-motile and grew on marine agar 2216 as beige colonies. Phylogenetic analyses of 16S rRNA gene sequences revealed a clear affiliation of the novel strains to the family Rhodobacteraceae. However, the novel strains were only distantly related to members of the Roseobacter clade, forming a distinct lineage. Although the 16S rRNA gene sequence similarity between strains CL-SP27T and B5-6T was very high (99.6 %), DNA–DNA relatedness between the strains was 48.4 %, suggesting that the strains be categorized as two genospecies. Additionally, the two novel strains could be differentiated by DNA G+C contents, fatty acid profiles, carbon source utilization patterns, antibiotic susceptibilities and biochemical characteristics. Based on taxonomic data obtained in this study, strains CL-SP27T and B5-6T represent separate species within a novel genus of the family Rhodobacteraceae, for which the names Maribius salinus gen. nov., sp. nov. (type species) and Maribius pelagius sp. nov. are proposed. The type strains of Maribius salinus and Maribius pelagius are CL-SP27T (=KCCM 42113T=JCM 13037T) and B5-6T (=KCCM 42336T=JCM 14009T), respectively.


2013 ◽  
Vol 63 (Pt_12) ◽  
pp. 4797-4804 ◽  
Author(s):  
Shih-Yi Sheu ◽  
Yi-Ling Chen ◽  
Chiu-Chung Young ◽  
Wen-Ming Chen

A bacterial strain designated LTC-2T was isolated from a freshwater lake in Taiwan and characterized using a polyphasic taxonomic approach. Cells of strain LTC-2T were Gram-reaction-negative, facultatively anaerobic, poly-β-hydroxybutyrate-accumulating, motile by means of a monopolar flagellum, non-spore-forming, slightly curved rods surrounded by a thick capsule and formed creamy white colonies. Growth occurred at 10–37 °C (optimum, 20–30 °C), at pH 6.0–9.0 (optimum, pH 7.0–8.0) and with 0–1.0 % NaCl (optimum, 0 %). The predominant fatty acids were C18 : 1ω7c, summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The major isoprenoid quinone was Q-10 and the DNA G+C content was 58.5 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, two uncharacterized phospholipids and two uncharacterized aminophospholipids. The major polyamines were putrescine, homospermidine and spermidine. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain LTC-2T forms a distinct lineage with respect to closely related genera in the family Rhodospirillaceae , most closely related to the genera Elstera and Dongia , and the levels of 16S rRNA gene sequence similarity with respect to the type species of related genera were less than 94 %. On the basis of the genotypic and phenotypic data, strain LTC-2T represents a novel genus and species of the family Rhodospirillaceae , for which the name Lacibacterium aquatile gen. nov., sp. nov. is proposed. The type strain is LTC-2T ( = BCRC 80445T = LMG 26999T = KCTC 32017T).


2012 ◽  
Vol 62 (Pt_3) ◽  
pp. 624-631 ◽  
Author(s):  
Sung Hun Kim ◽  
Hyun Ok Yang ◽  
Yun Kyung Shin ◽  
Hak Cheol Kwon

A Gram-negative, aerobic, ovoid to rod-shaped bacterial strain, KME 002T was isolated from a marine ascidian, Halocynthia roretzi, off the coast of Gangneung, Korea. Phylogenetic analyses based on 16S rRNA gene sequences showed that this strain belonged to the family Rhodobacteraceae in the class Alphaproteobacteria and was closely related to the type strains of Dinoroseobacter shibae, Roseovarius crassostreae and Pseudoruegeria aquimaris with 95.0, 94.7 and 94.5 % 16S rRNA gene sequence similarities, respectively. KME 002T was an obligately halophilic bacterium requiring 1 to 5 % (w/v) NaCl, with an absolute requirement for magnesium chloride for growth. Cells were motile by means of a single polar flagellum and showed budding fission. The predominant cellular fatty acid of the isolate was C18 : 1ω7c and Q-10 was the major ubiquinone. The DNA G+C content of the strain was 71.6 mol%. The major secondary metabolites from cultures in liquid medium were cholic acid derivatives, including 3α,12α-hydroxy-3-keto-glycocholanic acid, 12-hydroxy-3-keto-glycocholanic acid, nutriacholic acid and deoxycholic acid. These characteristics determined in this polyphasic study suggest that strain KME 002T represents a novel species in a new genus of the family Rhodobacteraceae. The name Hasllibacter halocynthiae gen. nov., sp. nov. is proposed for this isolate, and the type strain is KME 002T ( = JCM 16214T = KCCM 90082T).


2012 ◽  
Vol 62 (Pt_8) ◽  
pp. 1819-1824 ◽  
Author(s):  
Chao Zhao ◽  
Zhaoming Gao ◽  
Qiwei Qin ◽  
Lingwei Ruan

A Gram-negative, obligately anaerobic, non-spore-forming, long rod-shaped bacterium strain P2T was isolated from the offshore mangrove sediment of the South China Sea. Growth was observed at between 22 and 39 °C, with an optimum at 35 °C. The pH range for growth was 5.0–8.5, with an optimum around pH 7.0–7.5. Salt tolerance was determined between 0.2 and 3.5 % (w/v), optimum at 0.5–1.0 %. Catalase and oxidase activities were negative. Strain P2T utilized cysteine, lactate, pyruvate, yeast extract or H2/CO2+acetate as electron donors, and sulfate or sulfite as electron acceptors. Metabolism was strictly fermentative. The main organic fermentation products were propionate, acetate and succinate. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain P2T formed a distinct evolutionary lineage within the family Marinilabiliaceae . Strain P2T was most closely related to members of the genera Alkaliflexus (92.0 % 16S rRNA gene sequence similarity), Marinilabilia (91.7 %) and Anaerophaga (89.9 %) of the family Marinilabiliaceae . The DNA G+C content of the novel strain was 44.2±1.0 mol%. The dominant fatty acids of strain P2T were iso-C15 : 0 (33.5 %), anteiso-C15 : 0 (18.9 %), C16 : 0 (5.4 %), C16 : 0 3-OH (7.7 %) and iso-C17 : 0 3-OH (13.3 %). The respiratory quinone was menaquinone 7 (100 % of total quinone) and the major polar lipid was phosphatidylethanolamine. Strain P2T was distinguishable from members of phylogenetically related genera by differences in several phenotypic properties. On the basis of phylogenetic, phenotypic and physiological evidence, a novel genus, Mangroviflexus, is proposed to harbour strain P2T ( = CGMCC 1.5167T = DSM 24214T) which is described as the type strain of a novel species, Mangroviflexus xiamenensis gen. nov., sp. nov.


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