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1.
Paavo Ahvenniemi Matthias Wolf Mari J. Lehtonen Paula Wilson Malgorzata German-Kinnari Jari P. T. Valkonen 《Journal of molecular evolution》2009,69(2):150-163
The rRNA cistron (18S–ITS1–5.8S–ITS2–28S) is used widely for phylogenetic analyses. Recent studies show that compensatory
base changes (CBC) in the secondary structure of ITS2 correlate with genetic incompatibility between organisms. Rhizoctonia solani consists of genetically incompatible strain groups (anastomosis groups, AG) distinguished by lack of anastomosis between
hyphae of strains. Phylogenetic analysis of internal transcribed spacer (ITS) sequences shows a strong correlation with AG
determination. In this study, ITS sequences were reannotated according to the flanking 5.8S and 28S regions which interact
during ribogenesis. One or two CBCs were detected between the ITS2 secondary structure of AG-3 potato strains as compared
to AG-3 tobacco strains, and between these two strains and all other AGs. When a binucleate Rhizoctonia species related to Ceratobasidiaceae was compared to the AGs of R. solani, which were multinucleate (3–21 nuclei per cell), 1–3 CBCs were detected. The CBCs in potato strains of AG-3 distinguish
them from AG-3 tobacco strains and other AGs yielding further evidence that the potato strains of AG-3 originally described
as R. solani are a species distinct from other AGs. The ITS1–5.8S–ITS2 sequences were analyzed by direct sequencing of PCR products from
497 strains of AG-3 isolated from potato. The same 10 and 4 positions in ITS1 and ITS2, respectively, contained variability
in 425 strains (86%). Nine different unambiguous ITS sequences (haplotypes) could be detected in a single strain by sequencing
cloned PCR products indicating that concerted evolution had not homogenized the rRNA cistrons in many AG-3 strains. Importantly,
the sequence variability did not affect the secondary structure of ITS2 and CBCs in AG-3.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Luciano Z. Goldani Valério R. Aquino Luciano W. Lunardi Vanessa S. Cunha Rodrigo P. Santos 《Mycopathologia》2009,167(4):181-186
Objectives Skin lesions, uncommon in US cases (<10%), occur in 38–85% of cases reported from Latin America. Although these differences
may reflect reporting bias, delayed diagnosis, or differences in host immune response among different ethnic groups, they
also could result from genetic differences changing the pathobiology of the organism. It is possible that genetic differences
among strains of H. capsulatum may influence the pathogenesis and clinical manifestations of histoplasmosis.
Methods We examined the clinical features of patients with mucocutaneous manifestations of histoplasmosis and performed genetic analysis
based on nucleotide sequence variations in the internal transcribed spacer regions of rRNA genes of H. capsulatum isolates of patients. Two pairs of PCR primers were designed to develop and amplify the ITS regions of H. capsulatum, 5′-TACCCGGCCACCCTTGTCTA-3′ and 5′-AGCGGGTGGCAAAGCCC-3′. These primers were based on the ITS sequence of Ajellomyces capsulatus, the ascomycetous teleomorph form of H. capsulatum, deposited in the GenBank (accession number U18363). Eight patients attending a tertiary-care hospital in southern Brazil
were enrolled into the study. All case patients had skin cultures growing H. capsulatum at the mycology laboratory.
Results Six of eight (75%) patients were HIV-positive and presented involvement of multiples organs by H. capsulatum. Two HIV-negative patients did not present evidence of involvement of other organs besides mucosa and skin. ITS sequencing
of a DNA H. capsulatum fragment of 485-bp from isolates of 8 patients revealed two distinct strains. The 2 distinct fragments (Hc1, Hc2) differed
from each other at 7 positions in the ITS regions. They were identical to strains of H. capsulatum isolated in patients from Colombia and Argentina, but different from strains isolated in US. Hc1 and Hc2 were isolated in
5 patients and 3 patients, respectively, with mucocutaneous manifestations of histoplasmosis. Both Hc1 and Hc2 strains were
isolated in HIV-infected and non-HIV-infected patients.
Conclusions Mucocutaneous manifestations of histoplasmosis, which are frequently seen in Brazilian patients were caused by 2 specific
strains in our institution. Those strains have been isolated in patients with these particular clinical features of histoplasmosis
in Latin America. Our study suggests that unique pathogenic characteristics among the Latin American species of H. capsulatum might explain its increased dermatotropism. 相似文献
3.
An attempt was made to explore the genotyping of Trichophyton rubrum (T. rubrum) and the relationship between genotype and geographical origin using ribosomal restriction endonuclease polymorphic analysis.
The total DNA was extracted by cetyltrimethyl ammonium bromide (CTAB). The probe was amplified from part of the 18S, ITSI,
5.8S, and ITSII region of T. rubrum standard strain with the universal fungal primers NS5 [5′-AACTT AAAGG AATTG ACGGA AG-3′] and ITS4 [5′-TCCTC CGCTT ATTGA TATGC-3′].
The genomic DNA of 49 clinical T. rubrum isolates digested by EcoR1 were hybridized with this probe, and the hybridization patterns were used as the basis of genotyping. Of the data from
49 strains of T. rubrum studied (21 from Nanjing, 26 from Dalian, and two from Beijing), 20 individual patterns (DNA Type A–T) were identified, among
which Type A–C accounted for 48.98% of all the strains. The DNA patterns of Nanjing strains were represented by three bands,
those of Dalian strains were represented by four bands. The DNA typing of T. rubrum by Southern blotting was highly sensitive and highly distinguishable. The DNA patterns of Nanjing strains were obviously
different from those of Dalian strains. 相似文献
4.
To investigate the diversity of root endophytes in Rhododendron fortunei, fungal strains were isolated from the hair roots of plants from four habitats in subtropical forests of China. In total,
220 slow-growing fungal isolates were isolated from the hair roots of R. fortunei. The isolates were initially grouped into 17 types based on the results of internal transcribed spacer-restriction fragment
length polymorphism (ITS-RFLP) analysis. ITS sequences were obtained for representative isolates from each RFLP type and compared
phylogenetically with known sequences of ericoid mycorrhizal endophytes and selected ascomycetes or basidiomycetes. Based
on phylogenetic analysis of the ITS sequences in GenBank, 15 RFLP types were confirmed as ascomycetes, and two as basidiomycetes;
nine of these were shown to be ericoid mycorrhizal endophytes in experimental cultures. The only common endophytes of R. fortunei were identified as Oidiodendron maius at four sites, although the isolation frequency (3–65%) differed sharply according to habitat. Phialocephala fortinii strains were isolated most abundantly from two habitats which related to the more acidic soil and pine mixed forests. A number
of less common mycorrhizal RFLP types were isolated from R. fortunei at three, two, or one of the sites. Most of these appeared to have strong affinities for some unidentified root endophytes
from Ericaceae hosts in Australian forests. We concluded that the endophyte population isolated from R. fortunei is composed mainly of ascomycete, as well as a few basidiomycete strains. In addition, one basidiomycete strain was confirmed
as a putative ericoid mycorrhizal fungus. 相似文献
5.
Among 59 Korean isolated, 20 were confirmed as members of the genusBifidobacterium species based on gram staining, microscopic examination of cell morphology and the TLC method. The oxygen tolerance and antioxidative
activities of these 20Bifidobacterium strains and 5 standardBifidobacterium strains were tested. All the strains demonstrated antioxidative activities as regards inhibiting linoleic acid peroxidation.
The antioxidative activities of isolated and standard strains were found to range from 10.7–46.4% and from 10.7–22.2%, respectively.
In addition, all tested strains exhibited a scavenging ability on DPPH free radicals, range from 15–41% for the isolated strains
and 8.3–22% for the standard strain. Accordingly, the isolatedBifidobacterium strains demonstrated higher antioxidative activities than the 5 standardBifidobacterium strains. On the base of grades for each test, HJL 7511 was identified as the best strain, followed by HJL 7501. 2 strains
were identified with Polymerase Chain Reaction (PCR) assay using group-specific primers designed from the nucleotide sequences
of the 16S rRNA and internal transcribed spacer (ITS) regions of the Bifidobacteria. Based on the sequencing results, HJL
7511 and HJL 7501 were identified asBifidobacterium infantis. 相似文献
6.
产黄酮成分的绶草内生真菌的鉴定 总被引:4,自引:0,他引:4
利用薄层层析法进行的定性分析表明,分离自绶草Spiranthes sinensis的3株内生真菌产生了黄酮类化合物,在形态学鉴定的同时,扩增、测序了3株内生真菌的rDNA的ITS序列,利用MEGA4.0软件和邻接法(Neighbour-joining methods)进行了聚类分析,菌株S-1鉴定为不等弯孢Curvularia inaequalis,S-2和S-3鉴定为嗜松青霉Penicillium pinophilum。 相似文献
7.
Zuming Li Zhihui Bai Baoguo Zhang Huijun Xie Qing Hu Chunbo Hao Wentong Xue Hongxun Zhang 《World journal of microbiology & biotechnology》2005,21(8-9):1483-1486
Summary A Bacillus strain capable of growing under highly alkaline conditions was isolated from a sample of alkaline soil. The isolate was a
Gram-positive, spore-forming, aerobic, alkaliphilic bacterium and was designated as strain S-2. Growth of the strain was observed
in the pH range of 7–12 and temperature range of 4–40 °C. Sequence analysis of the 16S rDNA of the strain revealed more than
99% homology with the strains of Bacillus gibsonii. The S-2 strain was confirmed as B. gibsonii by comparing its physiological and biochemical characteristics with the B. gibsonii DSM 8722 strain. The S-2 strain could use sugar beet pulp as the carbon source as well as the pectinase inducer to produce
extracellular alkaline pectinase by solid-state fermentation. The maximum polygalacturonase yield of 3600 U/g dry sugar beet
pulp was obtained at 35 °C after 48 h of incubation. 相似文献
8.
Conrads G Citron DM Mutters R Jang S Goldstein EJ 《Systematic and applied microbiology》2004,27(4):407-413
Fourteen strains of Gram-negative, anaerobic, fluoroquinolone-resistant, non-sporulating rods were isolated from various infections in cats and dogs, as well as from wounds in humans after cat- or dog-bites. These strains were characterized by sequencing of the 16S-23S rDNA internal transcribed spacer (ITS) regions, 16S rDNA, DNA-DNA hybridization, phylogenetic analysis, and phenotypic tests. The results indicate that the novel strains belong to a distinct species, closely related to Fusobacterium nucleatum. The species Fusobacterium canifelinum sp. nov. is proposed, with strain ATCC BAA 689T as the type strain. 相似文献
9.
Braulio Esteve-Zarzoso María José Peris-Torán Daniel Ramón Amparo Querol 《Antonie van Leeuwenhoek》2001,80(1):85-92
The sequences of the internal transcribed spacers (ITS regions) and the 5.8S rRNA gene, together with the electrophoretic karyotypes of 27 strains representative of the six species belonging to the genus Hanseniaspora, were examined. From the analysis of the 5.8S rRNA gene and the ITS regions, the genus Hanseniaspora is monophyletic and can be divided into two subgroups. This subdivision was supported by electrophoretic chromosome patterns. Hanseniaspora guilliermondii, H. uvarum and H. valbyensis show 6–7 bands (8 to 9 chromosomes), while the second group comprises the species H. occidentalis, H. osmophila and H. vineae which have only 5 chromosomes. 相似文献
10.
Ok Tae Kim Kyong Hwan Bang Dong Su In Jei Wan Lee Young Chang Kim Yoo Soo Shin Dong Yun Hyun Sung Sik Lee Seon Woo Cha Nak Sul Seong 《Plant biotechnology reports》2007,1(3):163-167
Molecular authentication among three Panax species and within cultivars and accessions of P. ginseng was investigated using the DNA sequence in the ribosomal ITS1–5.8S–ITS2 region. Four single-nucleotide polymorphisms were
identified between P. ginseng and other Panax species. In the electrophoresis profile, obtained after digestion with the enzyme TaqI, three fingerprinting patterns were obtained from cultivars and accessions of Panax species. Consequently, this authentication procedure based upon the restriction fragment length polymorphism in the ribosomal
ITS1–5.8S–ITS2 region can now be utilized to differentiate these Panax species as well as major Korean cultivars such as Gopoong and Kumpoong from other cultivars and accessions in Panax species at the DNA level.
O. T. Kim and K. H. Bang contributed equally to this paper. 相似文献
11.
Kiran Nehra Attar S. Yadav Anita R. Sehrawat R. K. Vashishat 《Indian journal of microbiology》2007,47(4):329-335
Fourteen heat resistant mutant strains were isolated from a wild-type strain (PP201, Nod+ Fix+) of Rhizobium sp. (Cajanus) by giving it a heat shock of 43°C. These mutant strains showed a greater increase in optical density (O.D.) and a higher
viable cell count in both rhizospheric and non-rhizospheric soil at high temperature. Symbiotic studies showed that pigeon
pea plants inoculated with a few mutant strains had ineffective nodules (Nod+ Fix−) under controlled temperature (43°C) conditions, but under natural high temperature (40–45°C) conditions, the host plants
infected with all the mutant strains showed higher total shoot nitrogen than the plants inoculated with the parent strain.
Four mutant strains (HR-3, HR-6, HR-10 and HR-12) were found to be highly efficient for all the symbiotic parameters, and
thus have the potential to be used as bioinoculants in the North-Western regions of India during the summer season. 相似文献
12.
Biogeography and Degree of Endemicity of Fluorescent Pseudomonas Strains in Soil 总被引:7,自引:0,他引:7
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Fluorescent Pseudomonas strains were isolated from 38 undisturbed pristine soil samples from 10 sites on four continents. A total of 248 isolates were confirmed as Pseudomonas sensu stricto by fluorescent pigment production and group-specific 16S ribosomal DNA (rDNA) primers. These isolates were analyzed by three molecular typing methods with different levels of resolution: 16S rDNA restriction analysis (ARDRA), 16S-23S rDNA intergenic spacer-restriction fragment length polymorphism (ITS-RFLP) analysis, and repetitive extragenic palindromic PCR genomic fingerprinting with a BOX primer set (BOX-PCR). All isolates showed very similar ARDRA patterns, as expected. Some ITS-RFLP types were also found at every geographic scale, although some ITS-RFLP types were unique to the site of origin, indicating weak endemicity at this level of resolution. Using a similarity value of 0.8 or more after cluster analysis of BOX-PCR fingerprinting patterns to define the same genotypes, we identified 85 unique fluorescent Pseudomonas genotypes in our collection. There were no overlapping genotypes between sites as well as continental regions, indicating strict site endemism. The genetic distance between isolates as determined by degree of dissimilarity in BOX-PCR patterns was meaningfully correlated to the geographic distance between the isolates' sites of origin. Also, a significant positive spatial autocorrelation of the distribution of the genotypes was observed among distances of <197 km, and significant negative autocorrelation was observed between regions. Hence, strong endemicity of fluorescent Pseudomonas genotypes was observed, suggesting that these heterotrophic soil bacteria are not globally mixed. 相似文献
13.
Morten Skage Anders Hobæk Štĕpánka Ruthová Barbara Keller Adam Petrusek Jaromír Sed’a Piet Spaak 《Hydrobiologia》2007,594(1):19-32
A collaborative research effort was undertaken to evaluate the robustness of a recently developed genetic tool for species
identification of members in the morphologically variable Daphnia longispina species complex. This genetic method, based on restriction fragment length polymorphism (RFLP) of the internal transcribed
spacer region (ITS) of nuclear ribosomal DNA (rDNA) with restriction enzymes Mwo I and Sau96 I [Billiones et al., 2004. Hydrobiologia 526: 43–53], was applied to many different European populations. Results were
compared with two or more independently obtained characters (morphology, allozymes, mitochondrial DNA (mtDNA), or cloned rDNA-ITS
sequences). Individuals of most taxa were readily identified, but unexpected ITS-RFLP patterns were found in many individuals
indicated by other markers to be D. galeata or one of its hybrids. Among 43 investigated D. galeata populations (902 specimen analysed by ITS-RFLP), deviant RFLP fragment patterns occurred in 26 (i.e., more than half) of
the populations. The deviant patterns could be attributed to the loss of one single restriction site in the ITS2 region. This
loss made the distinction of D. galeata from other species unreliable, and F1 hybrids could not be identified. Future users should be aware of this shortcoming of
the Billions et al. [2004. Hydrobiologia 526: 43–53] protocol. As a solution to this problem, we present an improved genetic
identification protocol based on a simple double digestion of the rDNA-ITS region with the restriction enzymes BsrB I and EagI. Sequence analyses of rDNA-ITS clones and preliminary testing indicate that the new protocol is unaffected by the rDNA variation
which troubled the Mwo I/Sau96 I protocol. Further, the new protocol identifies all European species of the D. longispina complex, as well as their F1 hybrids. However, a wider screening is required to verify its general utility for all species,
since yet unknown variation may occur.
Guest editor: Piet Spaak
Cladocera: Proceedings of the 7th International Symposium on Cladocera 相似文献
14.
Yin Li Zhiqiang Liu Fengjie Cui Yingying Xu Hui Zhao 《World journal of microbiology & biotechnology》2007,23(6):837-843
A new strain of Penicillium sp. ZH-30 that produces xylanase was isolated from soil. According to the morphology and comparison of internal transcribed
spacer (ITS) rDNA gene sequence, the strain Penicillium sp. ZH-30 was identified as a strain of Penicillium oxalicum. When xylan or wheat bran was used as substrate at 30°C for 3 days under submerged cultivation, xylanase production was 5.3
and 13.3 U ml−1, respectively. The temperature and pH for optimum activity were 50°C and 5.0–6.0, respectively. 相似文献
15.
Genetic diversity among 27 isolates (23 from chickpea and 4 from other host crops) of Rhizoctonia bataticola representing 11 different states of India was determined by random amplified polymorphic DNA (RAPD), internal transcribed
spacer restriction fragment length polymorphism (ITS-RFLP) and ITS sequencing. The isolates showed variability in virulence
test. Unweighted paired group method with arithmetic average cluster analysis was used to group the isolates into distinct
clusters. The clusters generated by RAPD grouped all the isolates into six categories at 40% genetic similarity. High level
of diversity was observed among the isolates of different as well as same state. Some of the RAPD (OPN 4, OPN 12, and OPN
20) markers clearly distinguished majority of the isolates into the area specific groups. The ITS I, 5.8rDNA and ITS II regions
of 11 isolates representing different RAPD groups were amplified with primers ITS 1 and ITS 4 and digested with seven restriction
enzymes. The restriction enzymes DraI, MboI, RsaI, and AluI were found to be suitable for differentiating the isolates into five categories by showing isolate specific ITS-RFLP patterns.
The isolates were variable in their nucleotide sequences of the ITS regions. This is the first study on genetic diversity
among chickpea isolates of R. bataticola. 相似文献
16.
Diversity of the Bacillus thuringiensis (Bt) in the rice field soils of different ecologies viz. the island (Port Blair), the Himalayan (Srinagar), brackish water
(Mahe) and coastal mesophilic (Mangalore) habitats was analyzed by phenotypic characterization of 5, 66, 14 and 54 Bt isolates,
respectively. The Bt isolates produced either monotypic (bipyramidal or spherical) or heterotypic (polymorphic-bipyramidal
or bipyramidal-rhomboidal) crystals. The organisms were generally resistant to the penicillin group of antibiotics, tolerated
5–12% NaCl and 0.5M Na-acetate. The Bt isolates contained 1–5 plasmids of 0.89–58.61 kbp sizes. The plasmid profiles had no
correlation with crystal morphology or salt tolerance of different bacteria. Each soil was inhabited by different types of
Bt. Two Bt strains of Mangalore and one strain each of the other places were phenotypically similar. One Bt strain each of
Port Blair and Srinagar was different from all other strains. 相似文献
17.
Nir N Bahalul M Feingersch R Katz-Ezov T Kashi Y Fishman A 《Applied microbiology and biotechnology》2008,78(4):659-667
The asymmetric bio-reduction of 4-chloro-acetoacetic-acid-ethyl-ester to the pharmaceutical building block (S)-4-chloro-3-hydroxybutanoate-ethyl-ester requires the utilization of an enantioselective robust biocatalyst. Some of the
natural Saccharomyces cerevisiae strains, isolated from Mount Carmel National Park in Israel, were characterized as resistant to environmental stress. Nevertheless,
these strains showed relatively low enantiomeric-excess (ee), while a laboratory strain, Y103, exhibited a selectivity of
98% ee. The enantioselective lab strain was crossed with the multi-stress resistant environmental isolate (93% ee) followed
by backcross with Y103, to subsequently obtain a haploid offspring of backcross-1, exhibiting both high multi-stress resistance
and high enantioselectivity (98% ee). Introducing osmotic (1 M NaCl), oxidative (0.6 mM H2O2) and thermal stress (44°C) to growing cultures of the enantioselective parent, resulted in a decrease of 24–32% in specific
activity, while the enantioselectivity of the stress-resistant parent decreased by 4–12% ee. Unlike its original parental
strains, the new strain maintained constant specific activity and enantioselectivity when introduced to the various stress
factors. This work shows that the classic introgression method, can serve as a viable approach for creating a robust enantioselective
biocatalyst, designed for industrial production of chiral compounds. 相似文献
18.
Among the basidiomycetous yeasts isolated from plant leaves collected in different regions of China, two ballistoconidium-forming
strains were revealed to represent an undescribed species of the genus Bensingtonia by conventional, chemotaxonomic and molecular phylogenetic characterization. Sequence analysis of the 26S rDNA D1/D2 domains
and the internal transcribed spacer (ITS) region indicated that the novel species was located in the Agaricostilbum lineage
and closely related to Bensingtonia naganoensis and Bensingtonia ciliata, with the former as its closest relative. The name Bensingtonia pseudonaganoensis sp. nov. is proposed (type strain: AS 2.2601T = CBS 10121T) 相似文献
19.
I. Tzovenis E. Fountoulaki N. Dolapsakis I. Kotzamanis I. Nengas I. Bitis Y. Cladas A. Economou-Amilli 《Journal of applied phycology》2009,21(4):457-469
Mediterranean mariculture uses imported strains of marine phytoplankton, raising questions of ecological risk and ability
to adapt to local conditions for mass culture outdoors. In this context, we report here on the mass-culture potential and
chemical composition of six strains of Prasinophyceae (five strains of Tetraselmis sp. and one Pyramimonas sp.) isolated from a Greek coastal lagoon. Proximate composition had a pattern of 10–20% ash, 35–65% protein, 6–10% lipids,
and 25–45% other organics including carbohydrates. The amino acid profiles were typical for the marine representatives of
the class. All strains had a high PUFA content with dominant the ω3 fraction in four of them. The fatty acid profiles indicated
a Tetraselmis strain with high EPA (14%) and a Pyramimonas strain with high DHA (6%). These strains might be a good alternative for the common commercial strains used in Mediterranean
aquaculture. 相似文献
20.
Genetic diversity of 11 representative isolates of Fusarium oxysporum f.sp. ciceris causing chickpea wilt was determined through internal transcribed spacer (ITS) region of the ribosomal DNA-restriction fragment
length polymorphism (ITS-RFLP). ITS1+5.8s+ITS2 regions of the isolates were amplified with a set of primers ITS1 and ITS4
and amplified products were digested with 4 restriction enzymes (AluI, MboI, RsaI, MseI). Six different kinds of ITS-RFLP patterns were obtained. The ITS region of these isolates was sequenced and deposited to
NCBI GeneBank. The nucleotide sequence homology of ITS region grouped the isolates into 5 categories. Primers were designed with sequence
information using Primer 3 software. F. oxysporum f.sp. ciceris specific markers (FOC F2 and FOC R2) based on ITS region were developed for the first time for detection of the pathogen.
The markers produced an amplicon of 292 bp; they were validated against the isolates of the pathogen collected from different
locations of India. 相似文献