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1.
Five novel ascosporogenous yeast strains (H382, H396, H409, H433T and H441) were found through a survey of vacuum-packed beef microbiota. Sequence analysis of ITS domain and LSU rRNA genes showed that the new strains represent a distinct lineage within the genus Kazachstania, closely related to Kazachstania lodderae (97.0 % identity) and Kazachstania ichnusensis (96.1 % identity). The main difference of strains H382, H396, H409, H433T and H441 to strains of known Kazachstania species is the maximum growth temperature, which is below 20 °C for the new strains, whereas related species grow at 25 °C. Furthermore, the strains differed from known Kazachstania species in assimilation and fermentation patterns of carbon sources. Based on these characteristics, the five strains are considered to represent a novel species of the genus Kazachstania for which the name Kazachstania psychrophila sp. nov. is proposed. The type strain is H433T (DSM 26230T=CBS 12689T). The Mycobank number of the type strain is MB 803980.  相似文献   

2.
Eleven yeast strains representing two hitherto undescribed species were isolated from different kinds of meat samples in Hungary and one from the sediment of a tropical freshwater river in Southeastern Brazil. The analysis of the sequences of their large subunit rRNA gene D1/D2 domain and the internal transcribed spacer (ITS) regions placed the two new species in the Yarrowia clade. Some of the seven strains representing the first new species can mate and give rise to asci and form ascospores embedded in capsular material, which qualifies it as the third teleomorph species of the Yarrowia clade. The name Yarrowia porcina sp. nov. (type strain: NCAIM Y.02100T = CBS 12935T = NRRL Y-63669T, allotype strain UFMG-RD131A = CBS 12932A) is proposed for this new yeast species, which, based on physiological characters, is indistinguishable from Yarrowia lipolytica and some other species of the genus. Considerable intraspecific variability was detected among the sequences of the large subunit rRNA gene D1/D2 domains of the seven strains. The variability among the D1/D2 sequences exceeded the divergence observed among the ITS sequences and in some cases more than 1 % substitution among the D1/D2 sequences was detected. The conspecificity of these strains was supported by the low (0–3 substitutions) sequence divergence among their ITS sequences, the result of a parsimony network analysis utilizing the concatenated ITS and D1/D2 sequences and also by the fingerprint patterns generated by microsatellite primed PCR. No ascospore formation was observed in the group of the other five strains representing the second new species. These strains shared identical D1/D2 and ITS sequences. Yarrowia bubula f.a., sp. nov. (type strain: NCAIM Y.01998T = CBS 12934T = NRRL Y-63668T) is proposed to accommodate these strains.  相似文献   

3.
Three hundred and thirty-seven xylose-utilizing yeast strains were isolated from various natural samples. Among these, 68 strains produced xylitol in the range of 0.1–0.69 g xylitol/g xylose. Thirty-nine xylitol-producing strains were identified to be Candida tropicalis. Ten strains were found belonging to 14 known species in the genus Candida, Cyberlindnera, Meyerozyma, Pichia, Wickerhamomyces, Yamadazyma and Cryptococcus. Two strains were identified to be two Candida species and two strains (DMKU-XE142T and DMKU-XE332) were found to be a novel species. Strain DMKU-XE142T was isolated from tree bark and DMKU-XE332 was obtained from decaying plant leaf collected in Thailand. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics and sequence analysis of the D1/D2 region of the large subunit rRNA gene (LSU) and the internal transcribed spacer (ITS) region, the two strains were determined to represent a novel Yamadazyma species although formation of ascospores was not observed. The sequences of the D1/D2 region of the LSU rRNA gene and the ITS region of the two strains were identical but differed from Yamadazyma phyllophila, the closest species in terms of pairwise sequence similarity of the D1/D2 region, by 1.7 % nucleotide substitutions and 3.5 % nucleotide substitutions in the ITS region. The name Yamadazyma ubonensis f.a., sp. nov. is proposed (type strain is DMKU-XE142T = BCC 61020T = CBS 12859T).  相似文献   

4.
Three strains representing one novel yeast species were isolated from the phylloplanes of the vetiver grasses (DMKU-LV90 and DMKU-LV99T) and sugarcane (DMKU-SP260) collected in Thailand by leaf washing followed by a plating technique. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics and the sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer region (ITS), the three strains were found to represent a single novel anamorphic ustilaginomycetous yeast species in the genus Pseudozyma. The name Pseudozyma vetiver sp. nov. is proposed for this novel species. The type strain is DMKU-LV99T (BCC 61021 = CBS 12824). The novel species showed phylogenetic relationships to the other members of the genus Pseudozyma and to teleomorphic fungal genera, namely Ustilago, Sporisorium and Anomalomyces in Ustilaginaceae, Ustilaginales. The three strains showed identical sequences both in the D1/D2 and ITS regions. The Pseudozyma species closest to the novel species in terms of pairwise sequence similarity in the D1/D2 region was Pseudozyma pruni but with 2.3 % nucleotide substitutions (14 nucleotide substitutions and no gaps out of 606 nt). The novel species and P. pruni differed by 10.9 % nucleotide substitutions (75 nucleotide substitutions and 31 gaps out of 691 nt) in the ITS region. The phylogenetic analysis based on the combined sequences of the ITS region and the D1/D2 region of the LSU rRNA gene showed that the novel species was found to be most closely related to Pseudozyma fusiformata but with 2.9 % nucleotide substitutions in the D1/D2 region and 7.4 % nucleotide substitutions in the ITS region.  相似文献   

5.
Four strains representing three novel anamorphic yeast species were isolated from the external surface of sugarcane leaves (DMKU-RK254T), corn leaves (DMKU-RK548T), bean leaves (K129) in Thailand and hengchun pencilwood leaves (TrB1-1T) in Taiwan. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, the sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene, the internal transcribed spacer (ITS) region, the actin gene (ACT1) and the elongation factor 2 gene (EF2), the four strains were determined to represent novel Yamadazyma species although formation of ascospores was not observed. Strain DMKU-RK254T was determined to be related to Candida diddensiae, Candida naeodendra and Candida kanchanaburiensis but with 1.8, 1.8 and 2.0 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, respectively. It was assigned to Yamadazyma siamensis sp. nov. (type strain DMKU-RK254T = BCC 50730T = NBRC 108901T = CBS 12573T). The sequences of the D1/D2 region of the LSU rRNA gene, the ITS region, ACT1 gene and EF2 gene of two strains (DMKU-RK548T and K129) were identical but differed from that of strain TrB1-1T by 0.6, 1.0, 3.3 and 5.9 % nucleotide substitutions, respectively. Therefore, the two strains (DMKU-RK548T and K129) and strain TrB1-1T were assigned to be two separate species. The closest species in terms of pairwise sequences similarity of the D1/D2 region to the two novel species was Yamadazyma philogaea but with 1.1–1.7 % nucleotide substitutions. The two strains (DMKU-RK548T and K129) were assigned to Yamadazyma phyllophila sp. nov. (type strain DMKU-RK548T = BCC 50736T = NBRC 108906T = CBS 12572T) and the strain TrB1-1T was named Yamadazyma paraphyllophila sp. nov. (type strain TrB1-1T = BCRC 23030T = CCTCC AY 204005T = CBS 9928T).  相似文献   

6.
Species of the Paramecium aurelia complex show different levels of intraspecific polymorphism, with P. dodecaurelia revealing a high level of intraspecific variation. Paramecium dodecaurelia strains originating from distant localities in the Palaearctic, North America (USA), and Oceania (Hawaii) were studied in terms of intraspecific differentiation and the degree of speciation. Sequences of genes encoding the ITS1–5.8S-ITS2–5’ end of LSU rDNA (1063–1097 bp) and cytochrome c oxidase subunit I mtDNA (638–644 bp) were obtained from 33 strains of P. dodecaurelia, other P. aurelia species, and another species of the genus Paramecium, with Tetrahymena sp. used as an outgroup. In phylograms, the majority of P. dodecaurelia strains from the Palaearctic appear in one cluster, while strains from Japan, Hawaii and the USA are grouped in another cluster, together with some strains from Italy and representatives of the P. aurelia species complex. Our results tend to support the hypothesis that P. dodecaurelia seems to be a polyphyletic species with several haplotypes similar to or even shared with other members of the P. aurelia species complex. However, it is still an open question whether the revealed intraspecific differences within P. dodecaurelia are the result of ongoing speciation, or perhaps they just indicate genetic differentiation within a species that has a wide geographic distribution.  相似文献   

7.
A 433-bp fragment of the mitochondrial cytochrome b gene and the entire nuclear ITS2 region were sequenced in an oak gall wasp species, Andricus curtisii, which represents 21 populations across its range in Turkey. Forty cytochrome b haplotypes and 63 ITS2 alleles were discovered among the 161 individuals studied. Remarkable genetic variation was detected in the species, with an average haplotype diversity (h) of 0.72 and 0.76 and an average nucleotide diversity (π) of 0.06 and 0.01 for the cyt b gene and the ITS region, respectively. Most populations were genetically distinct, possessing unique cytochrome b haplotypes. Maximum likelihood and Bayesian phylogenetic analyses and application of the haplotype network to both datasets revealed that the most basally located haplotypes/alleles were from the eastern part of Turkey. The detection of older sequences in the phylogenetic trees of the easterly located populations implied an eastern origin of the species. The application of a conventional insect mitochondrial DNA clock to the dataset suggested a splitting of ingroup haplotypes from the outgroup lineages predating the Pleistocene epoch and the formation of two major haplogroups that coincided with the oscillation of the early Pleistocene glaciations.  相似文献   

8.
A new poroid wood-inhabiting fungal species, Ceriporiopsis kunmingensis sp. nov., is proposed based on morphological and molecular characters. The species is characterized by resupinate basidiocarps with pale cinnamon-buff to ochreous color when dry; generative hyphae unbranched and subparallel along the tubes; presence of hyphal ends; allantoid basidiospores, 4.5–5 × 1.5–2 μm. The internal transcribed spacer (ITS) and large subunit (LSU) regions of nuclear ribosomal RNA gene sequences of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony, and Bayesian inference methods. The phylogenetic analysis based on molecular data of ITS?+?nLSU sequences showed that C. kunmingensis belonged to the phlebioid clade, formed a monophyletic lineage with a strong support (100% BS, 100% BP, 1.00 BPP), and was closely related to Phlebia aurea, and then grouped with P. livida and P. subserialis. Both morphological and molecular characters confirmed the placement of the new species in Ceriporiopsis.  相似文献   

9.
Two strains of a novel basidiomycetous yeast species were isolated from the gut of wood-boring larvae collected in the Baotianman Nature Reserve, the central China. Sequence analysis of the D1/D2 domains of the large subunit (LSU) rRNA gene and internal transcribed spacer (ITS) regions showed that these yeasts belong to the Bulleromyces clade and formed a cluster together with eleven undescribed Cryptococcus species. The novel species differed from its closest known species, Cryptococcus rajasthanensis, by 3.3 % divergence (15 substitutions and 6 gaps over 630 bases) in the D1/D2 domains, and by 13.4 % divergence (41 substitutions and 27 gaps over 508 bases) in the ITS regions. Physiologically, the fermentation of glucose, galactose, sucrose, trehalose, and raffinose in Durham tubes was observed for the strains of this new yeast. Based on the phenotypical and molecular characteristics presented, the two strains are proposed as a new species, Cryptococcus nanyangensis sp. nov., with the type strain KCY-1T (=CICC 1976T = CBS 12474T).  相似文献   

10.
A total of 515 yeast strains were isolated from the nasal smears of Queensland koalas and their breeding environments in Japanese zoological parks between 2005 and 2012. The most frequent species in the basidiomycetous yeast biota isolated from koala nasal passages was Cryptococcus neoformans, followed by Rhodotorula minuta. R. minuta was the most frequent species in the breeding environments, while C. neoformans was rare. Seven strains representing two novel yeast species were identified. Analyses of the 26S rDNA (LSU) D1/D2 domain and nuclear ribosomal DNA internal transcribed spacer region sequences indicated that these strains represent new species with close phylogenetic relationships to Cryptococcus and Rhodotorula. A sexual state was not found for either of these two novel yeasts. Key phenotypic characters confirmed that these strains could be placed in Cryptococcus and Rhodotorula. The names Cryptococcus lacticolor sp. nov. (type strain TIMM 10013T = JCM 15449T = CBS 10915T = DSM 21093T, DDBJ/EMBL/Genbank Accession No.; AB375774 (ITS) and AB375775 (26S rDNA D1/D2 region), MycoBank ID; MB 802688, Fungal Barcoding Database ID; 3174), and Rhodotorula oligophaga sp. nov. (type strain TIMM 10017T = JCM 18398T = CBS 12623T = DSM 25814T, DDBJ/EMBL/Genbank Accession No.; AB702967 (ITS) and AB702967 (26S rDNA D1/D2 region), MycoBank ID; MB 802689, Fungal Barcoding Database ID; 3175) are proposed for these new species.  相似文献   

11.
Three strains (KM03T, KM13 T and KM15) representing two novel methylotrophic yeast species were isolated from the external surface of plant leaves, which were collected from Kanchanaburi province, Thailand, by three-consecutive enrichments in methanol broth. Strain KM03T was isolated from phylloplane of a mango tree (Mangifera indica) and two strains, KM13T and KM15, were obtained from phylloplane of different wine grapes (Vitis vinifera). The sequences of the D1/D2 region of the large subunit (LSU) rRNA gene of the two strains (KM13T and KM15) were identical and differed markedly from that of strain KM03T. In terms of pairwise sequence similarity of the D1/D2 region the closest species to the strains KM13T and KM15 were Candida suzukii (CBS 9253T) and Candida nitratophila (CBS 2027T) but with 2.1 % nucleotide substitutions. Strain KM03T differed from Ogataea wickerhamii (CBS 4307T), its closest relative, by 2.3 % nucleotide substitutions. Phylogenetic analysis based on the D1/D2 sequences placed the three strains in the Ogataea clade. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, the sequence analyses of the D1/D2 and the internal transcribed spacer (ITS) regions of the nuclear ribosomal RNA gene (nrRNA) operon, the three strains represent two novel Ogataea species although formation of ascospores was not observed. Ogataea kanchanaburiensis sp. nov. is proposed for strain KM03T (=BCC 47626T = NBRC 108603T = CBS 12673T). Two strains, KM13T and KM15, were assigned to Ogataea wangdongensis sp. nov. (type strain KM13T = BCC 42664T = NBRC 107778T = CBS 12674T). GenBank/EMBL/DDBJ accession numbers for the sequences of the D1/D2 and the ITS regions of O. kanchanaburiensis KM03T are AB734090 and AB734093, respectively, of O. wangdongensis KM13T are AB734091 and AB734094, respectively, and of O. wangdongensis KM15 are AB734092 and AB734095, respectively.  相似文献   

12.

Background

Polyporus umbellatus is an important medicinal fungus distributed throughout most area of China. Its wide distribution may have resulted in substantial intraspecific genetic diversity for the fungus, potentially creating variation in its medical value. To date, we know little about the intraspecific genetic diversity of P. umbellatus.

Methodology/Principal Findings

The objective of this research was to assess genetic differences of P. umbellatus from geographically diverse regions of China based on nrDNA ITS and 28S rRNA (LSU, large subunit) sequences. Significant sequence variations in the ITS and LSU sequences were detected. All sclerotial samples were clustered into four clades based on phylogenetic analysis of ITS, LSU and a combined data set of both regions. Heterogeneity of ITS and LSU sequences was detected in 5 and 7 samples respectively. All clone sequences clustered into the same clade except for one LSU clone sequences (from Henan province) which clustered into two clades (Clade I and Clade II). Significant genetic divergence in P. umbellatus was observed and the genetic diversification was greater among sclerotial samples from Shaanxi, Henan and Gansu provinces than among other provinces. Polymorphism of ITS and LSU sequences indicated that in China, P. umbellatus may spread from a center (Shaanxi, Henan and Gansu province) to other regions.

Conclusions/Significance

We found sclerotial samples of P. umbellatus contained levels of intraspecific genetic diversity. These findings suggested that P. umbellatus populations in Shaanxi, Henan and Gansu are important resources of genetic diversity and should be conserved accordingly.  相似文献   

13.
The genetic diversity of the endangered crocodile Tomistoma schlegelii was characterized using the protein coding ND 6-tRNAglu-cyt b and the cytochrome b-control region (cyt b-CR) markers. Concatenate data revealed six haplotypes with an overall haplotype diversity of 0.769 ± 0.039; nucleotide diversity was 0.00535 ± 0.00172. A nearest-neighbor analysis showed that all individuals clustered with four geographic regions (Sumatra, Peninsular Malaysia, Sarawak, and East Kalimantan) and were genetically differentiated. With the exception of the individuals from haplotype H2, which occurred in both Peninsular Malaysia and Sarawak, all other haplotypes were geographically distinct. The H4 lineage, which was found to be the most divergent, clustered exclusively in the basal clade in all phylogenetic trees, and the haplotype network was unconnected at the 95% reconnection limit, suggesting further investigation to establish its possible status as a distinct evolutionary significant unit or a cryptic species.  相似文献   

14.
Most molecular ecological studies of arbuscular mycorrhizal fungi (AMF) have been based on the rRNA gene sequences. However, information about intraspecific nucleotide variation is still limited in these fungi. In this study, we calculated the inter- and intrasporal nucleotide variation of Diversispora sp. EE1 using 78 cloned sequences from four spores within a ca 4960 bp fragment of the nuclear ribosomal operon spanning the near full length small ribosomal subunit (SSU) rRNA gene, the full internal transcribed spacer (ITS: ITS1-5.8S-ITS2) and ca 2740 bp of the large ribosomal subunit (LSU) rRNA gene. Data for each marker region (SSU, ITS and LSU) originated from the very same spores. Sequence variation resulting from point mutations and small indels was recorded in all regions. Highest sequence variation was observed in the ITS region at both the inter- and intrasporal levels. The ITS1 component was more variable than ITS2, whilst the 5.8S gene was the least variable component of the ITS region. Evolutionary divergence of gene copies between spores was intermediate for the LSU and lowest for the SSU. The SSU and the LSU genes had relatively similar evolutionary divergence per spore. Sequence variant richness was not exhaustive for any of the marker regions, indicating that multiple sequences per spore from multiple spores are needed when characterizing a species. This study provides reference sequences for ecological studies, permitting identification of AMF using any of the ribosomal regions or primer systems.  相似文献   

15.
A novel methanol assimilating yeast species Komagataella kurtzmanii is described using the type strain VKPM Y-727 (=KBP Y-2878 = UCD-FST 76-20 = Starmer #75-208.2 = CBS 12817 = NRRL Y-63667) isolated by W.T. Starmer from a fir flux in the Catalina Mountains, Southern AZ, USA. The new species is registered in MycoBank under MB 803919. The species was differentiated by divergence in gene sequences for D1/D2 LSU rRNA, ITS1-5.8S-ITS2, RNA polymerase subunit I, translation elongation factor-1α and mitochondrial small subunit rRNA. K. kurtzmanii differs from its phenotypically similar sibling species Komagataella pastoris, Komagataella pseudopastoris, Komagataella phaffii, Komagataella populi and Komagataella ulmi by absence of growth at 35 °C and inability to assimilate trehalose.  相似文献   

16.
17.
Paramecium novaurelia Beale and Schneller, 1954, was first found in Scotland and is known to occur mainly in Europe, where it is the most common species of the P. aurelia complex. In recent years, two non-European localities have been described: Turkey and the United States of America. This article presents the analysis of intraspecific variability among 25 strains of P. novaurelia with the application of ribosomal and mitochondrial loci (ITS1-5.8S-ITS2, 5′ large subunit rDNA (5′LSU rDNA) and cytochrome c oxidase subunit 1 (COI) mtDNA). The mean distance observed for all of the studied P. novaurelia sequence pairs was p = 0.008/0.016/0.092 (ITS1-5.8S-ITS2/5′LSU rDNA/COI). Phylogenetic trees (NJ/MP/BI) based on a comparison of all of the analysed sequences show that the studied strains of P. novaurelia form a distinct clade, separate from the P. caudatum outgroup, and are divided into two clusters (A and B) and two branches (C and D). The occurrence of substantial genetic differentiation within P. novaurelia, confirmed by the analysed DNA fragments, indicates a rapid evolution of particular species within the Paramecium genus.  相似文献   

18.
The name Pleurotus opuntiae is indiscriminately used for describing mushrooms with white to off-white to white-grey pilei with short or absent stipe and dimitic hyphal system, which grow on plants of the genera Opuntia, Yucca, Agave, Phytolacca etc. However, the outcome of the present study evidences that this name should be reserved for specimens deriving from the Mediterranean area only; an epitype originating from Italy on Opuntia ficus-indica is designated. Pertinent material was sequenced by using the internal transcribed spacer region (ITS) and found to be phylogenetically related to P. djamor from Kenya and Nigeria, while members of the P. djamor complex from other continents were clearly more distant. Results were further corroborated by examining the large subunit of nuclear ribosomal DNA (LSU) and the second subunit of RNA polymerase II (RPB2). The P. djamor complex shows high intraspecific polymorphism evidenced by sequence divergence and genetic distance values, presents a cosmopolitan distribution and also comprises material initially identified as P. flabellatus, P. opuntiae, P. ostreatoroseus, P. parsonsiae and P. salmoneostramineus. An ITS tree including representative specimens from all major Pleurotus species is provided for the first time and ambiguous taxa are discussed in the context of new findings.  相似文献   

19.
In the full sequences of the mtDNA cytochrome b gene, 26 haplotypes (Tamias sibiricus barberi) from six localities of central and southern Korea were distinct from 21 haplotypes (Tamias sibiricus orientalis) from five localities of northeast China and Vladivostok, Russia. The average Tamura–Nei nucleotide distance between the subspecies (11.40%) and maximum infrasubspecific distances (3.74% and 4.72%) support the subspecies classification of T. s. barberi based on morphometric comparison. The 26 haplotypes of T. s. barberi were also distinct from 2 haplotypes of T. s. orientalis and Tamias sibiricus jacutensis from far-east Russia (average distance, 11.86%). Thus T. s. barberi constitutes a “phylogroup” (average nucleotide distance > 10%); analyses with nuclear genes of northeast Asian specimens, including North Korean ones, are necessary to clarify its taxonomic status. Furthermore, 49 haplotypes of T. sibiricus from eastern Asia differed from 19 haplotypes of another 18 Tamias spp. from America (weighted-average distance, 18.58%). T. sibiricus is, therefore, distinct enough to be recognized as a subgenus, Eutamias.  相似文献   

20.
Four yeast strains were isolated from rotting wood samples collected from two sites in the Baotianman Nature Reserve and the Laojieling Nature Reserve in China. DNA sequence comparison and other taxonomic characteristics identified the strains as a single novel species of the genus Metschnikowia. The name Metschnikowia henanensis sp. nov. is proposed to accommodate these highly divergent organisms with the type strain BY-97T (= CICC 1982T = CBS 12677T). The novel species produced chlamydospores, but it did not exhibit ascospore formation in sporulation media for 4 weeks. Molecular phylogeny from the D1/D2 domains of the large subunit (LSU) rRNA gene sequences placed this new species in a basal position to the Metschnikowia viticola/Candida kofuensis/Metschnikowia noctiluminum subclade, and an undescribed Candida species namely strains IMB-EMP4 and IMB-EMP5 was a close sister to M. henanensis.  相似文献   

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