• Title/Summary/Keyword: 16S ribosomal DNA sequence

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The Base Sequence of ITS and Genetic Variation in Sarcodon Aspratus (능이버섯의 ITS염기서열과 유전적 변이)

  • Kim Jong Bong
    • Journal of Life Science
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    • v.14 no.6 s.67
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    • pp.963-966
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    • 2004
  • The sequence of ITS (partial 16S ribosomal DNA, complete ITS1, 5.8S ribosomal DNA and ITS2, and partial 28S ribosomal DNA) was analysed by PCR and autosequencing in Sarcodon aspratus. The ITS lenght of S. aspratus was 716 base pair. As this sequence compared with other reports on S. aspratus (ace No AF335110), the sequence variation based on nucleotide deletion and substitution was $1.8\%$. This nucleotide variation rate in same species was very higher than in other species. Also, the sequence varitation rates between this S. aspratus and S. imbricatus, and S. squamus were $8\%\;and\;10\%$, respectively. This results suggested that the high sequence variation of S. aspratus might be caused specific host and inhabitat environment which limited gene flow.

Application of rDNA-PCR Amplification and DGGE Fingerprinting for Detection of Microbial Diversity in a Malaysian Crude Oil

  • Liew, Pauline Woan Ying;Jong, Bor Chyan
    • Journal of Microbiology and Biotechnology
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    • v.18 no.5
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    • pp.815-820
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    • 2008
  • Two culture-independent methods, namely ribosomal DNA libraries and denaturing gradient gel electrophoresis (DGGE), were adopted to examine the microbial community of a Malaysian light crude oil. In this study, both 16S and 18S rDNAs were PCR-amplified from bulk DNA of crude oil samples, cloned, and sequenced. Analyses of restriction fragment length polymorphism (RFLP) and phylogenetics clustered the 16S and 18S rDNA sequences into seven and six groups, respectively. The ribosomal DNA sequences obtained showed sequence similarity between 90 to 100% to those available in the GenBank database. The closest relatives documented for the 16S rDNAs include member species of Thermoincola and Rhodopseudomonas, whereas the closest fungal relatives include Acremonium, Ceriporiopsis, Xeromyces, Lecythophora, and Candida. Others were affiliated to uncultured bacteria and uncultured ascomycete. The 16S rDNA library demonstrated predomination by a single uncultured bacterial type by >80% relative abundance. The predomination was confirmed by DGGE analysis.

Taxonomic Studies of the Beta Hemolysis-causing Pathogen Bacillus cereus Isolated from Sea Water

  • Kim, Sam-Sun;Park, Yong-Ha;Lee, Jung-Sook;Yoon, Jung-Hoon;Shin, Yong-Kook;Rhee, In-Koo;Kim, Young-Jae
    • Journal of Microbiology and Biotechnology
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    • v.8 no.1
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    • pp.67-73
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    • 1998
  • A bacterial strain that excretes hemolysins and proteases into the growth medium was isolated from sea water and designated as KYJ 961. A nearly complete nucleotide sequence of a 16S ribosomal RNA gene from the isolate was determined following the isolation and cloning of amplified genes. On the basis of the 16S ribosomal DNA sequence data, and morphological, chemotaxonomic, and physiological characteristics, strain KYJ 961 was classified as a strain of Bacillus cereus.

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Genotypic and Phenotypic Diversity of PGPR Fluorescent Pseudomonads Isolated from the Rhizosphere of Sugarcane (Saccharum officinarum L.)

  • Rameshkumar, Neelamegam;Ayyadurai, Niraikulam;Kayalvizhi, Nagarajan;Gunasekaran, Paramsamy
    • Journal of Microbiology and Biotechnology
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    • v.22 no.1
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    • pp.13-24
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    • 2012
  • The genetic diversity of plant growth-promoting rhizobacterial (PGPR) fluorescent pseudomonads associated with the sugarcane (Saccharum officinarum L.) rhizosphere was analyzed. Selected isolates were screened for plant growthpromoting properties including production of indole acetic acid, phosphate solubilization, denitrification ability, and production of antifungal metabolites. Furthermore, 16S rDNA sequence analysis was performed to identify and differentiate these isolates. Based on 16S rDNA sequence similarity, the isolates were designated as Pseudomonas plecoglossicida, P. fluorescens, P. libaniensis, and P. aeruginosa. Differentiation of isolates belonging to the same group was achieved through different genomic DNA fingerprinting techniques, including randomly amplified polymorphic DNA (RAPD), amplified ribosomal DNA restriction analysis (ARDRA), repetitive extragenic palindromic (REP), enterobacterial repetitive intergenic consensus (ERIC), and bacterial repetitive BOX elements (BOX) analyses. The genetic diversity observed among the isolates and rep-PCR-generated fingerprinting patterns revealed that PGPR fluorescent pseudomonads are associated with the rhizosphere of sugarcane and that P. plecoglossicida is a dominant species. The knowledge obtained herein regarding the genetic and functional diversity of fluorescent pseudomonads associated with the sugarcane rhizosphere is useful for understanding their ecological role and potential utilization in sustainable agriculture.

Genome-based identification of strain KCOM 1265 isolated from subgingival plaque at the species level

  • Park, Soon-Nang;Lim, Yun Kyong;Kook, Joong-Ki
    • International Journal of Oral Biology
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    • v.45 no.2
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    • pp.70-75
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    • 2020
  • The aim of this study was to identify strain KCOM 1265 isolated from subgingival plaque at the species level by comparing 16S ribosomal RNA gene (16S rDNA) and genome sequences. The whole genome of strain KCOM 1265 was extracted using the phenol-chloroform extraction method. 16S rDNA was amplified using polymerase chain reaction and sequenced using the dideoxy chain termination method. Pairwise genome comparison was performed using average nucleotide identity (ANI) and genome-to-genome distance (GGD) analyses. The data showed that the percent similarity of 16S rDNA sequence of strain KCOM 1265 was 99.6% as compared with those of Fusobacterium polymorphum ATCC 10953T and Fusobacterium hwasookii KCOM 1249T. The ANI values of strain KCOM 1265 with F. polymorphum ATCC 10953T and F. hwasookii KCOM 1249T were 95.8% and 93.0%, respectively. The GGD values of strain KCOM 1265 with F. polymorphum ATCC 10953T and F. hwasookii KCOM 1249T were 63.9% and 49.6%, respectively. These results indicate that strain KCOM 1265 belongs to F. polymorphum.

Molecular Differentiation of Bacillus spp. Antagonistic Against Phytopathogenic Fungi Causing Damping-off Disease

  • Cho, Min-Jeong;Kim, Young-Kwon;Ka, Jong-Ok
    • Journal of Microbiology and Biotechnology
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    • v.14 no.3
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    • pp.599-606
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    • 2004
  • Gram-positive antagonistic bacilli were isolated from agricultural soils for possible use in biocontrol of plant pathogenic fungi, Fusarium oxysporum, Rhizoctonia solani, and/or Pythium ultimum. Among the 65 antagonistic Gram-positive soil isolates, 22 strains were identified as Bacillus species by 16S rDNA sequence analyses. Four strains, including DF14, especially exhibited multiple antagonistic properties against the three damping-off fungi. Genotypic properties of the Bacillus isolates were characterized by rapid molecular fingerprinting methods using repetitive extragenic palindromic-PCR (REP-PCR), ribosomal intergenic spacer-length polymorphisms (RIS-LP), 16S rDNA PCR-restriction fragment length polymorphisms (PCR-RFLP), and strain-specific PCR assays. The results indicated that the REP-PCR method was more valuable than the RIS-LP and 16S rDNA PCR-RFLP analyses as a rapid and reliable approach for bacilli typing and identification. The use of strain-specific primers designed based on 16S rDNA sequence comparisons enabled it to be possible to selectively detect a strain, DF14, which is being used as a biocontrol agent against damping-off fungi.

DNA Barcoding of Benthic Ragworms of the Genus Nectoneanthes (Polychaeta: Nereididae) Collected in Korean Waters

  • Park, Taeseo
    • Animal Systematics, Evolution and Diversity
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    • v.37 no.3
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    • pp.235-241
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    • 2021
  • To provide better taxonomic information of the genus Nectoneanthes, the two DNA barcode regions of mitochondrial cytochrome c oxidase subunit I (COI) and 16S ribosomal DNA (rDNA) sequences of Nectoneanthes oxypoda and N. uchiwa were determined. In addition, the respective sequences of four nereidid species closely related to Nectoneanthes were retrieved from GenBank for comparison and to estimate intra- and inter-specific genetic distances. The aligned sequence lengths of COI and 16S rDNA were 570 bp and 419 bp long, respectively. The mean intraspecific variation in both markers was less than 1% in all species except for that in COI of H. diadroma (1.87%). The mean interspecific variation between N. oxypoda and N. uchiwa was 12.02% regarding COI and 1.85% regarding 16S rDNA. In contrast, the mean interspecific variation between species of other genera was comparably higher(i.e., genus Perinereis: 20.5% in COI and 8.3% in 16S rDNA; genus Hediste: 13.18% in COI and 2.64% in 16S rDNA), compared with that between the two Nectoneanthes species. This result indicated that these Nectoneanthes species are genetically more closely related than other congeneric species of different genera. The DNA barcoding information on Nectoneanthes species generated in this study provides valuable insights for further biodiversity studies on nereidid species.

Intrageneric Relationships of Trichoderma Based on Internal Transcribed Spacers and 5.8S rDNA Nucleotide Sequences

  • Kim, Gi-Young;Lee, Goang-Jae;Ha, Myung-Gyu;Lee, Tae-Ho;Lee, Jae-Dong
    • Mycobiology
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    • v.28 no.1
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    • pp.11-16
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    • 2000
  • The nucleotide sequences of the internal transcribed spacer (ITS) regions of the ribosomal DNA including the 5.8S ribosomal RNA gene (rDNA) have been determined for 11 species in order to analyze their intrageneric relationships. The total length of these sequences ranged from 530 nucleotides for Trichoderma reesei KCTC 1286 to 553 nucleotide for Trichoderma koningii IAM 12534. Generally speaking, the length of ITS1 region was about 30 nucleotides longer than that of the ITS2 region. Also, the sequences of 5.8S rDNA were more conserved in length and variation than those of ITS regions. Although the variable ITS sequences were often ambiguously aligned, the conserved sites were also found. Thus, a neighbor-joining tree was constructed using the full sequence data of the ITS regions and the 5.8S rDNA. The Trichoderma genus used to be grouped on the basis of the morphological features and especially the shape of phialides needs to be reexamined. The phylogenetic tree displayed the presence of monophylogeny in the species of Trichoderma. Therefore, it was difficult to distinguish the intrageneric relationships in the Trichoderma genus.

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PCR and RFLP variation of conserved region of small subunit ribosomal DNA among Acanthamoeba isolates assigned to either A. castellanii or A. polyphaga (카스텔라니가시아메바 혹은 대식가시아메바로 분류된 분리주간의 ribosomaIDNA conserved region의 PCR-RFLP의 다양성)

  • 공현희;정동일
    • Parasites, Hosts and Diseases
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    • v.34 no.2
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    • pp.127-134
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    • 1996
  • Twelve isolates of Accnthamoebc app. assigned to either A. castellanii or A. poIMphoSa, and type strains of A. culbefsoni, A. henIWi, A. pqkestinefiE, and A. astronyxi,s were examined by restriction fragment length polymorphism (RFLP) of a conserved region of small subunit ribosomal RMh gene (ssu rDNA) amplified by polymerase chain reaction (PCR). The PCR products of the isolates measured approximately 910-930 bp, except for that of A. astronyxis which was extraordinarily long, approximately 1,170 bp. Average of estimated sequence divergence of the amplified DNA among the isolates assigned to A. castellanii was 9.8% whereas that among the isolates assigned to A. polvphusn 9.6%. The maximum intraspecific sequence divergence among the isolates assigned to A. costellanii was observed between the Chang and Ma strains (17.3%) while that among the isolates assigned to A. poIWphosa was observed between KA/S3 and KA/S7 strains (16.1%). The both maximum sequence divergences were much greater than the minimum interspecific sequence divergence between A. cnstellnnii and A. polwphasa (2.6%) which appeared between the Castellani (or CCAP 1501/12 g) and KA/S3 strains. The PCR-RFLP patterns of A. culbertsoni, A. healyi, A. palestinensis, and A. ostronvxis were quite diverse from one another and from those of isolates assigned to either A. castellanii or A. polyphoga. It is suggested that taxonomic validity of the isolates assigned to either A. castellnnii or A. polyphoga should be reevaluated.

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