首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The taxonomic position of the marine genera Alteromonas, Pseudoalteromonas, Idiomarina, and Colwellia within the gamma subclass of the class Proteobacteria were specified on the basis of their phenotypic, genotypic, and phylogenetic characteristics. Gram-negative aerobic bacteria of the genera Alteromonas, Pseudoalteromonas, and Idiomarina and facultatively anaerobic bacteria of the genus Colwellia were found to form a phylogenetic cluster with a 16S rRNA sequence homology of 90% or higher. The characteristics of these genera presented in this paper allow their reliable taxonomic identification. Based on the analysis of our experimental data and analyses available in the literature, we propose to combine the genera Alteromonas, Pseudoalteromonas, Idiomarina, and Colwellia into a new family, Alteromonadaceae fam. nov., with the type genus Alteromonas.  相似文献   

2.
A comparative study of the lipid composition of 26 strains (including type strains) of marine Gammaproteobacteria belonging to the genera Shewanella, Alteromonas, Pseudoalteromonas, Marinobacterium, Microbulbifer, and Marinobacter was carried out. The bacteria exhibited genus-specific profiles of ubiquinones, phospholipids, and fatty acids, which can serve as reliable chemotaxonomic markers for tentative identification of new isolates. The studied species of the genus Shewanella were distinguished by the presence of two types of isoprenoid quinones, namely, ubiquinones Q-7 and Q-8 and menaquinones MK-7 and MMK-7; five phospholipids typical of this genus, namely, phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), lyso-PE, and acyl-PG; and the fatty acids [15:0, 16:0, 16:1 (n-7), 17:1 (n-8), i-13:0, and i-15:0]. The high level of branched fatty acids (38–45%) and the presence of eicosapentaenoic acid (4%) may serve as criteria for the identification of this genus. Unlike Shewanella spp., bacteria of the other genera contained a single type of isoprenoid quinone: Q-8 (Alteromonas, Pseudoalteromonas, Marinobacterium, and Microbulbifer) or Q-9 (Marinobacter). The phospholipid compositions of these bacteria were restricted to three components: two major phospholipids (PE and PG) and a minor phospholipid, bisphosphatidic acid (Alteromonas and Pseudoalteromonas) or DPG (Marinobacterium, Microbulbifer, and Marinobacter). The bacteria exhibited genus-specific profiles of fatty acids.  相似文献   

3.
Evolutionary relationships among marine species assigned to the genera Alteromonas, Oceanospirillum, Pseudomonas, and Alcaligenes were determined by an immunological study of their Fe-containing superoxide dismutases (FeSOD) and glutamine synthetases (GS), two enzymes with differentially conserved amino acid sequences which are useful for determining intermediate and distant relationships, respectively. Five reference antisera were prepared against the FeSODs from Alteromonas macleodii, A. haloplanktis, Oceanospirillum commune, Pseudomonas stanieri, and Deleya pacifica. For GS, a previously prepared antiserum to the enzyme from Escherichia coli was employed. Amino acid sequence similarities for both enzymes were determined by the quantitative microcomplement fixation technique and the Ouchterlony double diffusion procedure. Six evolutionary groups were detected by FeSOD sequence similarities: three subgroups within the genus Alteromonas, the genera Oceanospirillum and Pseudomonas, and a new genus, Deleya (to accommodate marine Alcaligenes). Only four groupings were delineated by the GS data: the latter three genera and one group composed of all the species of Alteromonas. Evidence that all of these subgroups are derived from the evolutionary lineage defined by the purple sulfur photosynthetic bacteria is presented.Abbreviations Alt Alteromonas - anti-Amac, anti-Ahal, anti-Ocom, anti-Psta, anti-Dpac antisera to the Fe-containing superoxide dismutases from Alteromonas macleodii 107, Alteromonas haloplanktis 121, Oceanospirillum commune 8, Pseudomonas stanieri 146, Deleya pacifica 62 - FeSOD Fe-containing superoxide dismutase - G+C guanine plus cytosine - GS glutamine synthetase - ImD immunological distance - MnSOD Mn-containing superoxide dismutase - Oce Oceanospirillum - Pse Pseudomonas - Rm relative mobility - rRNA ribosomal RNA - SOD superoxide dismutase Dedicated to the memory of Professor Roger Y. Stanier  相似文献   

4.
Type strains of bacteria of the genera Alteromonas, Pseudoalteromonas, Marinomonas, and Marinobacterand symbiotrophic bacteria isolated from the Far Eastern bivalve mollusks Crenomytilus grayanusand Mizuhopecten yessoensisand identified as Pseudoalteromonas nigrifaciensand P. citreawere tested for susceptibility to antibiotics. Of the ten antibiotics used in this study, benzylpenicillin, polymyxin, lincomycin, and oleandomycin were valuable for the polyphasic taxonomy of marine aerobic proteobacteria. Marine bacteria of the genera studied exhibited characteristic antibiotic susceptibility profiles, which were useful for the differentiation of the genera.  相似文献   

5.
6.
Two hundred and eighty-eight arsenic-resistant bacteria were isolated by an enrichment culture method from a total of 69 arsenic-contaminated soil-samples collected from Dantchaeng district in Suphanburi province (47 samples), and from Ron Phiboon district in Nakhon Sri Thammarat province (22 samples), in Central and Southern Thailand, respectively. Twenty-four of the 288 isolated arsenic-resistant bacteria were found to be arsenite-oxidizing bacteria. On the basis of their morphological, cultural, physiological, biochemical and chemotaxonomic characteristics, and supported by phylogenetic analysis based upon their 16S rRNA gene sequences, they were divided into five groups, within the genera Acinetobacter, Flavobacterium, Pseudomonas, Sinorhizobium and Sphingomonas, respectively. Within genera, phylogenetic analysis using the 16S rRNA gene sequences suggested that they were comprised of at least ten species, five isolates being closely related to known bacteria (Acinetobacter calcoaceticus NCCB 22016T, Pseudomonas plecoglossicida FPC951T, Ps. knackmussii B13T, Sinorhizobium morelense Lc04T, and Sphingomonas subterranea IFO16086T). The other five proposed species are likely to be new species closely related to Flavobacterium johnsoniae, Sinorhizobium morelense, Acinetobacter calcoaceticus and Pseudomonas plecoglossicida, but this awaits further characterization for confirmation of the taxonomic status. No overlap in isolated species or strains was observed between the two sites. The strain distribution and characterization are described.  相似文献   

7.
The systematics and taxonomy of North Americancyprinid fishes has historically been said tobe in a chaotic state of affairs. Much of theconfusion as to relationships of species restsin the lack of explicit phylogenetic hypothesesof species and reliance upon degree ofdistinctiveness of taxa or their overallsimilarity for generic placement. Some specieshave had more turbulent or variable taxonomichistories than others. The ornate shiner, Cyprinella ornata, is one of those species,having been placed in the genera Notropis,Codoma, and Cyprinella within the last20 years and found in current texts in any ofthese three genera. Most of the confusionregarding placement of this species has beenrelated to lack of explicit phylogenetichypotheses to formulate its classification, butto a certain degree some researchers haveignored phylogenetic studies and preferred torely upon its morphological distinctiveness orreproductive behavioral traits of questionablehomology to place it in a monotypic genus andalign it with the genera Pimephales andOpsopoeodus.I present a phylogenetic analysis based oncomplete Cytochrome b sequences fromornate shiners, other species of Cyprinella, purported relatives, and severalother species of the Shiner Clade to determinethe phylogenetic affinities of this enigmaticspecies. Molecular analysis reveals the ornateshiner to be more closely related to species ofCyprinella than to a Pimephalesplus Opsopoeodus clade as previouslydiscussed in one morphological analysis, or asargued by Page and Johnston (1990), Johnstonand Page (1992) and Page and Ceas (1989) basedon observations of spawning behaviors andhypotheses of homology between crevice-spawningand egg-clumping behaviors. This molecularanalysis is more consistent with earliermorphological phylogenetic hypotheses of Mayden(1989) wherein these two clades are notconsidered to be closely related and the ornateshiner is a member of the genus Cyprinella.  相似文献   

8.
Sluys  Ronald 《Hydrobiologia》1986,132(1):257-262
The genus Procerodes forms a heterogeneous assemblage of taxa. Although it is premature to attempt phylogenetic weighting of the characters, the genus contains three well delimited subgroups, one with a subantarctic, panaustral distribution, one world-wide in distribution, and one occurring principally in the northern hemisphere. Outside of these subgroups, species in this genus are problematic since a number of their features also occurs in other procerodids. All recognized groups exhibit a wide distributional range. Many of the world-wide taxonomic relations lie on the species level and some at the level of genera. Poor dispersal capacity of extant species of Procerodes suggests that the biogeographic patterns may be very old.  相似文献   

9.
Beleneva  I. A.  Zhukova  N. V.  Maslennikova  E. F. 《Microbiology》2003,72(4):472-477
The 525 strains of heterotrophic bacteria isolated from natural and cultured populations of the mussel Mytilus trossulus and the surrounding seawater were identified to a genus level on the basis of phenotypic analysis and the fatty acid composition of cell lipids. Gram-negative isolates were dominated by six genera of the family Enterobacteriaceae and by the genera Pseudoalteromonas, Vibrio, Photobacterium, Cytophaga/Flavobacterium/Bacteroides, Pseudomonas, and Moraxella. Gram-positive isolates were mainly represented by the genus Streptomyces. The taxonomic compositions of natural and cultured populations of the mussel M. trossulus in Peter the Great Bay were similar.  相似文献   

10.
The satellite DNA Msat-160 has been previously characterized in several species of the genus Microtus. Here we present the characterization of Msat-160 from Chionomys nivalis, a species with a very primitive karyotype. As in other Microtus species analyzed, C. nivalis Msat-160 is AT rich, has a monomer length of 160 bp, is undermethylated and is mainly located in all the pericentromeric heterochromatin of all autosomes and the X chromosome, but is completely absent from the Y chromosome. Hence, our results support the hypothesis that Msat-160 was initially distributed in the pericentromeric heterochromatin of all autosomes and the X chromosome. The taxonomic status of the genus Chionomys in relation to the genus Microtus is a very interesting issue, so we constructed phylogenetic dendrograms using Msat-160 sequences from several Microtus species. Although the results were not informative about this issue, the presence of Msat-160 in C. nivalis and Microtus species suggested that both genera are closely related and that this satellite DNA was present in the common ancestor. Studies of Msat-160 in different arvicoline species could help to determine the origin of this satellite and, perhaps, to establish the phylogenetic relationships of some arvicoline groups.  相似文献   

11.
A halophilic, aerobic Gram-negative bacterium, designated strain CVS-6T, was isolated from a sea salt evaporation pond on the Island of Sal in the Cape Verde Archipelago. Phylogenetic analysis of the 16S rRNA gene sequence revealed a clear affiliation of the organism with members of the family Idiomarinaceae. Sequence similarities between CVS-6T and the type strains of the species of the genera Pseudidiomarina and Idiomarina ranged from 93.7% to 96.9%. The major isoprenoid quinone was ubiquinone 8 (Q-8). The major cellular fatty acids were 15:0 iso (21.8%), 17:0 iso (12.5%), 17:1 iso ω9c (10.7%), and 16:1 ω7c (10.6%). The DNA G+C content was 51.6 mol%. The species represented by strain CVS-6T could be distinguished from the species of the genera Pseudidiomarina and Idiomarina; however, it was not possible to distinguish both genera from each other using the phenotypic or chemotaxonomic characteristics examined. Consequently, we propose that the species classified in the genus Pseudidiomarina should be transferred to the genus Idiomarina. We also propose that, on the basis of physiological and biochemical characteristics, strain CVS-6T (=LMG 23123=CIP 108836) represents a new species which we name Idiomarina insulisalsae.  相似文献   

12.
Phyllactinia is a unique genus within the Erysiphales (Ascomycota) having a partly endo-parasitic nature of the mycelium within the host plant tissues. We constructed phylogenetic trees for the genus Phyllactinia and its allied genera based on a total of 120 nucleotide sequences of the 28S rDNA and ITS regions to discuss their phylogenetic relationships with special references to host plants, biogeography, evolutionary dating, and taxonomy. The analysis of the Erysiphales confirmed the monophyly of the endo-parasitic genera, i.e. Leveillula, Phyllactinia, and Pleochaeta. Phyllactinia specimens used in this study were divided into six distinctive groups and three subgroups. Interestingly, Leveillula, an obligately endo-parasitic genus of the Erysiphales, grouped together with Phyllactinia, although this was not significantly supported by the Kishino–Hasegawa and Shimodaira–Hasegawa tests. This suggests that the evolution within this group of fungi occurred from partial endo-parasitism to obligate endo-parasitism. The host range of Phyllactinia is mostly confined to woody plants, especially deciduous trees. Betulaceae, Fagaceae, Ulmaceae, Moraceae, and Rosaceae may have close connections to the divergence of the groups and subgroups of Phyllactinia concerned. Most of these plant families are known as major members of the boreotropical flora of the Tertiary, which suggests an early Tertiary origin of this genus. A comparison of the phylogenies of hosts and parasites revealed that host range expansion at higher taxonomic levels (higher than family level) is independent of the phylogeny of plants. Conversely, host range expansions in lower taxonomic levels (infrafamilial or infrageneric) tend to occur within a single family or genus. An estimation of the evolutionary timing using a molecular clock approach suggested that Phyllactinia split from Pleochaeta about 60 M years ago (Ma) in the early Tertiary and divergence of the six major clades of Phyllactinia occurred between 5 and 40 Ma during the Oligocene and Miocene. Divergence within the major clades and within Leveillula occurred maybe from more than 5 Ma onwards during the Pliocene and Quaternary. This is the first comprehensive phylogenetic study of Phyllactinia and other endo-parasitic genera of the Erysiphales.  相似文献   

13.
Plasmopara penniseti is the sole member of the genus Plasmopara parasitic to Poaceae, after the genus Viennotia had been described to accommodate Plasmopara oplismeni. Morphological, ultrastructural, and molecular phylogenetic data indicate that Plasmopara penniseti is not closely related to the generic type, and it is, therefore, transferred to the newly described genus Poakatesthia. The view that the genera of downy mildews with pyriform to vesicular haustoria (Basidiophora, Benua, Bremia, Paraperonospora, Plasmopara, Plasmoverna, and Protobremia) include species parasitic to Poaceae has to be discarded. All of these genera are apparently restricted to dicotyledonous hosts.  相似文献   

14.
About 63 fungal endophytic isolates were separated from rhizomes of Paris polyphylla var. yunnanensis, which is a traditional medicinal plant mainly distributed in China. The isolates were characterized and grouped based on the culture characteristics and the morphology of colony growth and conidia. Eleven representative ones were selected for further taxonomical identification. Five genera namely Fusarium, Gliocladiopsis, Gliomastix, Aspergillus and Cylindrocarpon were identified on the basis of their morphological characterizations. Of them, the most frequent genus was Fusarium (i.e. Ppf1, Ppf3 and Ppf14). Their ITS-rDNA sequences were compared with those available in the GeneBank databases to obtain the closest related species by BLAST analysis as well as to analyze their phylogenetic affiliation. The isolates were identified as Gliocladiopsis irregularis (Ppf2), Plectosphaerella cucumerina (Ppf4), Padospora sp. (Ppf6), Gliomastix murorum var. murorum (Ppf7), Aspergillus fumigatus (Ppf9), Pichia guilliermondii (Ppf10), Neonectria radicicola (anamorph: Cylindrocarpon) (Ppf12) and one uncultured mycorrhizal ascomycete (Ppf13) separately based on their morphological and molecular features. The molecular characters of the endophytic fungi were basically coincident with their morphology. The broad diversity and taxonomic spectrum were exhibited by the endophytic fungi from P. polyphylla var. yunnanensis.  相似文献   

15.
The relationship between Litsea and related genera is currently unclear. Previous molecular studies on these taxa using cpDNA and nrITS were unable to produce well-resolved phylogenetic trees. In this study, we explored the potential of the rpb2 gene as a source of molecular information to better resolve the phylogenetic analysis. Although rpb2 was believed to be a single-copy gene, our cloning results showed that most species examined possessed several copies of these sequences. However, the genetic distance among copies from any one species was low, and these copies always formed monophyletic groups in our molecular trees. Our phylogenetic analyses of rpb2 data resulted in better resolved tree topologies compared to those based on cpDNA or nrITS data. Our results show that monophyly of the genus Litsea is supported only for section Litsea. As a genus, Litsea was shown to be polyphyletic. The genera Actinodaphne and Neolitsea were resolved as monophyletic groups in all analyses. They were also shown to be sisters and closer to the genus Lindera than to the genus Litsea. Our results also revealed that the genus Lindera is not a monophyletic group.  相似文献   

16.
17.
The seed morphology of 79 species of neotropical Miconieae (Melastomataceae) is presented. These species have been chosen, in majority, from the polyphyletic genus Leandra. A few other species from the polyphyletic genera Miconia, Ossaea, and Clidemia were also sampled, because of potential similarities. Sixteen morphological seed types are defined after analysis through light microscopy and scanning electron microscopy. The seed morphology appears to possess a great deal of variability on the level of the overall shape as well as the structure and the surface of the testa. The different types defined here do not match with genera or sections, but rather are composed of species coming from different genera. In comparison with a preliminary molecular phylogeny study done on Leandra, some types of seeds are related to well supported clades. In some cases seed morphology corresponds with natural groups of species, thus being of high phylogenetic importance.  相似文献   

18.
The “Vibrio fischeri species group” recently was reclassified as a new genus, Aliivibrio, comprising four species, Aliivibrio fischeri, Aliivibrio logei, Aliivibrio salmonicida, and Aliivibrio wodanis. Only limited phylogenetic analysis of strains within Aliivibrio has been carried out, however, and taxonomic ambiguity is evident within this group, especially for phenotypically unusual strains and certain strains isolated from bioluminescent symbioses. Therefore, to examine in depth the evolutionary relationships within Aliivibrio and redefine the host affiliations of symbiotic species, we examined several previously identified and newly isolated strains using phylogenetic analysis based on multiple independent loci, gapA, gyrB, pyrH, recA, rpoA, the luxABE region, and the 16S rRNA gene. The analysis resolved Aliivibrio as distinct from Vibrio, Photobacterium, and other genera of Vibrionaceae, and resolved A. fischeri, A. salmonicida, A. logei, and A. wodanis as distinct, well-supported clades. However, it also revealed that several previously reported strains are incorrectly identified and that substantial unrecognized diversity exists in this genus. Specifically, strain ATCC 33715 (Y-1) and several other strains having a yellow-shifted luminescence were not members of A. fischeri. Furthermore, no strain previously identified as A. logei grouped with the type strain (ATCC 29985T), and no bona-fide strain of A. logei was identified as a bioluminescent symbiont. Several additional strains identified previously as A. logei group instead with the type strain of A. wodanis (ATCC BAA-104T), or are members of a new clade. Two strongly supported clades were evident within A. fischeri, a phylogenetic structure that might reflect differences in the host species or differences in the ecological incidence of strains. The results of this study highlight the importance of basing taxonomic conclusions on examination of type strains.  相似文献   

19.
Most of the species of the family Rubiaceae with flowers arranged in head inflorescences are currently classified in three distantly related tribes, Naucleeae (subfamily Cinchonoideae) and Morindeae and Schradereae (subfamily Rubioideae). Within Morindeae the type genus Morinda is traditionally and currently circumscribed based on its head inflorescences and syncarpous fruits (syncarps). These characters are also present in some members of its allied genera, raising doubts about the monophyly of Morinda. We perform Bayesian phylogenetic analyses using combined nrETS/nrITS/trnT-F data for 67 Morindeae taxa and five outgroups from the closely related tribes Mitchelleae and Gaertnereae to rigorously test the monophyly of Morinda as currently delimited and assess the phylogenetic value of head inflorescences and syncarps in Morinda and Morindeae and to evaluate generic relationships and limits in Morindeae. Our analyses demonstrate that head inflorescences and syncarps in Morinda and Morindeae are evolutionarily labile. Morinda is highly paraphyletic, unless the genera Coelospermum, Gynochthodes, Pogonolobus, and Sarcopygme are also included. Morindeae comprises four well-supported and morphologically distinct major lineages: Appunia clade, Morinda clade (including Sarcopygme and the lectotype M. royoc), Coelospermum clade (containing Pogonolobus and Morinda reticulata), and Gynochthodes–Morinda clade. Four possible alternatives for revising generic boundaries are presented to establish monophyletic units. We favor the recognition of the four major lineages of Morindeae as separate genera, because this classification reflects the occurrence of a considerable morphological diversity in the tribe and the phylogenetic and taxonomic distinctness of its newly delimited genera.  相似文献   

20.
Few basidiomycetes are known to have a coelomycete anamorph. The partial SSU and LSU of nu-rDNA of three coelomycete genera (Chaetospermum, Giulia, Mycotribulus) were sequenced to determine their phylogenetic relationship. M. mirabilis was well placed in the Physalacriaceae, Agaricales, whereas G. tenuis clusters with the Corticiaceae, Corticiales. C. camelliae and C. artocarpi form a close relationship with the Sebacinaceae, Sebacinales. Although morphologically these coelomycetes are pycnidial and with appendaged conidia, they show no consistency in their phylogenetic relationship, belonging to disparate major taxonomic groups with putative teleomorphs in the Agaricales, Corticiales and Sebacinales. Further molecular studies of coelomycetes may be rewarding to evaluate their phylogenetic affinities.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号