• The Plant Pathology Journal
• /
• 제38권5호
• /
• pp.449-460
• /
• 2022

This study was performed to reveal phenotypic characters and identity of symbiont bacteria of Nasutitermes as well as investigate their potential as antagonist of plant pathogenic fungi. Isolation of the symbiont bacteria was carried out from inside the heads and the bodies of soldier and worker termite which were collected from 3 locations of nests. Identification was performed using phenotypic test and sequence of 16S ribosomal DNA (16S rDNA). Antagonistic capability was investigated in the laboratory against 3 phytopathogenic fungi i.e., Phytophthora capsici, Ganoderma boninense, and Rigidoporus microporus. Totally, 39 bacterial isolates were obtained from inside the heads and the bodies of Nasutitermes. All the isolates showed capability to inhibit growth of P. capsici, however, 34 isolates showed capability to inhibit growth of G. boninense and 32 isolates showed capability to inhibit growth of R. microporus. Two bacterial strains (IK3.1P and 1B1.2P) which showed the highest percentage of inhibition were further identified based on their sequence of 16S rDNA. The result showed that 1K3.1P strain was placed in the group of type strain and reference strains of Lysinibacillus fusiformis meanwhile 1B1.2P strain was grouped within type strain and reference strains Paenibacillus alvei. The result of this study supply valuable information on the role of symbiont bacteria of Nasutitermes, which may support the development of the control method of the three above-mentioned phytopathogenic fungi.

• The Plant Pathology Journal
• /
• 제28권1호
• /
• pp.93-100
• /
• 2012

The rhizobacterium NJ134, showing strong $in$ $vitro$ antifungal activity against $Fusarium$ $oxysporum$, was isolated from field grown tomato plants and identified as $Pseudomonas$ sp. based on 16S ribosomal DNA sequence and biochemical analyses. The antifungal compound purified by gas chromatography-mass spectrometry, infrared, and nuclear magnetic resonance analyses from NJ134 cultures was polyketide 2,4-diacetylphloroglucinol (DAPG). Analysis of the sequence of part of one of the genes associated with DAPG synthesis, $phlD$, indicated that the DAPG producer NJ134 was a novel genotype or variant of existing genotype termed O that have been categorized based on isolates from Europe and North America. A greenhouse study indicated that about $10^8$ CFU/g of soil NJ134 culture application was required for effective biocontrol of Fusarium wilt in tomato. These results suggest that a new variant genotype of a DAPG-producing strain of $Pseudomonas$ has the potential to control Fusarium wilt under the low disease pressure conditions.

• 생명과학회지
• /
• 제16권1호
• /
• pp.71-75
• /
• 2006

We analyzed the phylogenic relationships of 23 partial 18S rDNA sequences of 22 species (1 species has 2 strains) belonging to Sarcorptiforms include 4 new sequences, using several tools. Although geographic distributions are quite far from, sequence similarity of two strains of Dermatophygoides pteronyssinus isolated from Japan and New Zealand were very high. This result suggests that mite migration by animals including human occurred in the two continents. We investigated the Endeostigmata taxonomic relationship between the Prostigmata and Oribatida subgroups using small fragments (340-400 bp) of their 185 rDNA sequences. But Endeostigmata was not grouped with Oribatida or Prostigmata. In conclusion, it is first reported phylogenic relationship for classified mites included in Sarcoptiformes using 185 rDNA sequence analysis and its system is a very powerful tool for classification of mites.

• 한국식품위생안전성학회지
• /
• 제34권5호
• /
• pp.502-507
• /
• 2019

본 연구는 국내에 유통되는 두족류 제품에 대한 모니터링을 수행하였다. 문어와 오징어로 표기되어 판매되는 28개 제품을 대상으로 DNA 바코드를 분석하여 원재료의 종을 동정하였다. DNA 바코드 증폭을 위하여 미토콘드리아의 16S ribosomal RNA 및 cytochrome c oxidase subunit I 유전자 부위를 증폭하는 두 종류의 프라이머 세트를 선정하였으며, 이를 이용하여 증폭된 PCR 산물의 염기서열을 분석하였다. 확보한 염기서열은 'BLAST Search'를 이용하여 미국국립보건원 GenBank에 등록되어있는 생물 종의 염기서열과 비교하여 유사도와 매칭 점수를 고려하여 최종 종을 동정하였다. 동정결과, 원재료를 오징어로 표기한 12개 제품은 아메리카대왕오징어(Dosidicus gigas, n=3), 살오징어(Todarodes pacificus, n=9) 종으로 확인되었다. 반면 문어를 원재료로 표기한 16개 제품의 경우, 6개 제품에서 대만주머니낙지(Cistopus taiwanicus, n=1), 하이야주꾸미(Amphioctopus marginatus, n=1), Scaeurgus unicirrhus(n=1), 아메리카대왕오징어(Dosidicus gigas, n=3)로 동정되어 표기된 원재료와 불일치하였으며, 이 중 3개의 제품은 알레르기 유발 원재료인 오징어가 사용되었음을 확인하였다.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2005년도 생물공학의 동향(XVII)
• /
• pp.364-367
• /
• 2005

This study investigated the production of antioxidant from Actinomyces culture supernatant. For the research of the natural marine antioxidant, several bacteria were isolated from the coast of Je-ju in Korea. An actinomycetes strains, S-1 was identified to a genus level 16S ribosomal DNA sequence and fatty acid analysis. From these results and other characteristics described in the Bergey's Manual, this strain was identificated as a Nocardiopsis dassonvillei. Strain S-1 showed high activity of 1,1-diphenyl-2-prcrylhydrazyl radical scavenging. The hydroxyl radical scavenging ability of Nocardiopsis sp. S-1 supernatant was 53%. Nutritional and cultural conditions for the production of antioxidant by this organism under shake-flask conditions have optimized. Similary initial medium pH 7.6, incubation temperature of $25^{\cicr}C$, sodium chloride concentration 2.5 and incubation time of 8 day were found to be optimal.

• Animal cells and systems
• /
• 제6권1호
• /
• pp.13-18
• /
• 2002

Phylogenetic relationships of Korean Acidiella species were tested using mitochondrial 16S ribosomal RNA gene sequences. We used 16 published sequences as outgroup, and 10 new sequences for nine Korean Acidiella species as ingroup. The number of aligned sites was 1,281 bp, but 1,135 bp were used for the analysis after excluding sites with missing data or gaps. Among these 1,135 sites, 464 sites were variable and 340 were informative for parsimony analysis. Phylogenetic information was extracted from this data set using neighbor-joining, maximum likelihood and maximum parsimony methods and compared to a morphology-based phylogenetic hypothesis. Our molecular data suggest that: (1) the tribe Trypetini appears to be monophyletic even when the nine additional Acidiella species are added to our previous phylogenetic analysis; (2) all the Korean Acidiella species belong to the Trypeta group, but the genus Acidiella is not supported as monophyletic; (3) the close relationship of A. circumvaga, A. issikii, and A. sapporensis is supported; (4) the close relationship of A. pachypogon and two additional new Acidiella species is strongly supported; and (5) the possible presence of two or more cryptic species among the specimens previously identified as A. obscuripennis is suggested. Sequence data from the mitochondrial 16S rDNA allowed us to better understand the systematic status of Korean Acidiella species. They indicated that the current concept about the genus Acidiella is insufficient and needs to be refined further. This study also showed a few interesting relationships, that had not been recognized by morphological study alone. Based on this study, we were able to plan further experiments to analyze relationships within the Trypeta Group.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제2권1호
• /
• pp.37-53
• /
• 2001

Two regions of mtDNA genome, cytochrome oxidase subunit I (COI) and 165 ribosomal RNA (165 rRNA) genes, were sequenced for 15 species of the long-horned beetle belonging to four subfamilies and geographic samples of mulberry longicorn beetle, Apriona germari, from two localities in Korea. Ten samples of A. germari collected from Suwon and Busan revealed three COI haplotypes ranging in nucleotide divergence of 0.3% to 0.5%, and the two populations shared one common COI haplotype (80%). The sequence divergence among 15 species of the long-horned beetle was much higher in COI gene (12.3%∼39.4%) than 16S rRNA gene (7.2% to 23.1), and the maximum value in the COI gene is exceptional compared with other relevant studies, including that of Coleoptera. The greatly increased divergence in the COI gene, in facto was stemmed from a peculiar sequence of Prionus insularis belonging to Prioninne, divergence of which ranges from 31.2% to 39.3% from other species. We discussed possible reason of the divergence in this species. Due to the abnormality of COI gene divergence, decrease in phylogenetic signal was severe in COI nucleotide and, subsequently, the converted amino acid sequences, rendering us to put more confidence on the 16S5 rRNA gene data. Although the molecular phylogeny confidently supports the monophyletic origin of Lepturinae, the presence of discrepancy between molecular data and traditional taxonomic views also is a testable hyothesis. One such discrepancy includes taxonomic position of Sophronica obrioides and Theophilea cylindricollis belonging to Lamiinae.

• Journal of Microbiology and Biotechnology
• /
• 제16권2호
• /
• pp.193-199
• /
• 2006

Halotolerant spore-forming Gram-positive bacteria were isolated from the root, rhizosphere, and non-rhizosphere soil of Blutaparon portulacoides. The different isolates were characterized genetically using an amplified ribosomal DNA restriction analysis (ARDRA), and phenotypically based on their colonial morphology, physiology, and nutritional requirements. Three different 16S rRNA gene-based genotypes were observed at a 100% similarity using the enzymes HinfI, MspI, and RsaI, and the phenotypic results also followed the ARDRA groupings. Selected strains, representing the different ARDRA groups, were analyzed by 16S rDNA sequencing, and members of the genera Halobaeillus, Virgibacillus, and Oceanobacillus were found. Two isolates showed low 16S rDNA sequence similarities with the closest related species of Halobacillus, indicating the presence of new species among the isolates. The majority of the strains isolated in this study seemed to belong to the species O. iheyensis and were compared using an AP-PCR to determine whether they had a clonal origin or not. Different patterns allowed the grouping of the strains according to Pearson's coefficient, and the resulting dendrogram revealed the formation of two main clusters, denoted as A and B. All the strains isolated from the soil were grouped into cluster A, whereas cluster B was exclusively composed of the strains associated with the B. portulacoides roots. This is the first report on the isolation and characterization of halotolerant spore-forming Gram-positive bacteria that coexist with B. portulacoides. As such, these new strains may be a potential source for the discovery of bioactive compounds with industrial value.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제8권1호
• /
• pp.51-59
• /
• 2004

Phylogenetic relationships were analyzed among bumblebees using a portion of mitochondrial (mt) 16S ribosomal RNA (16S rRNA). Eight species of true bumblebees and one species of cuckoo bumblebee (Bombini, Apidae), collected from Korea were included in the analysis. Also, one species of true bumblebee imported from several foreign countries for pollination was included. The length of mt 16S rRNA sequence ranged from 496 bp to 508 bp and sequence divergence ranged from 1.4％ (7 bp) to 15.49％ (77bp). As expected, a high A＋T content was observed (78.5％ on average). According to the phylogeny tree derived from parsimony and maximum likelihood analysis, a monphyletic Bombus species, excluding a single cuckoo bumblebee, Psithyrus coreanus, was obtained, but the bootstrap estimate at the node supporting the monophyletic group was very weak (40％ or 46％), suggesting a very close relationship of the cuckoo bumblebee to the true bumblebee. Within Bombus species belonging to identical subgenera subgeneric specific clustering was formed with high bootstrap values, implying validity of the subgeneric names of each species: Pyrobombus for B. ardens and B. modeatus; Megabombus for B. consobrinus wittenburgi and B. koreanus; and Bombus s. str. for B. ignitus, B. hypocrita sapporoensis, and B. terrestris.

• 한국동물위생학회지
• /
• 제37권4호
• /
• pp.247-252
• /
• 2014

The economic impact of swine mycoplasma infection is high. An accurate diagnosis is often difficult and time consuming. We report the development and validation of an effective multiplex polymerase chain reaction (PCR) assay that detects Mycoplasma (M.) hyopneumoniae and M. hyorhinis. The multi detection of M. hyopneumoniae and M. hyorhinis primer set were employed to detect mycoplasma species and typing of the species was performed on the basis of sequence analysis of the PCR product. The target nucleic acid fragments were specifically amplified by M. hyopneumoniae and M. hyorhinis PCR with 16S ribosomal DNA primers. Single and mixed Mycoplasma species DNA templates were used to evaluate the specificity of the multiplex assay. The corresponding specific DNA products were amplified for each pathogen. The multiplex PCR assay provides a novel tool for simultaneous detection and differentiation of M. hyopneumoniae and M. hyorhinis.