• 한국미생물·생명공학회지
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• 제47권3호
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• pp.401-411
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• 2019

All Idiomarina species are isolated from saline environments; microorganisms in such extreme habitats develop metabolic adaptations and can produce compounds such as proteases with an industrial potential. ARDRA and 16S rRNA gene sequencing are established methods for performing phylogenetic analysis and taxonomic identification. However, 16S-23S ITS is more variable than the 16S rRNA gene within a genus, and is therefore, used as a marker to achieve a more precise identification. In this study, ten protease producing Idiomarina strains isolated from the Peruvian salterns were characterized using biochemical and molecular methods to determine their bacterial diversity and industrial potential. In addition, comparison between the length and nucleotide sequences of a 16S-23S ITS region allowed us to assess the inter and intraspecies variability. Based on the 16S rRNA gene, two species of Idiomarina were identified (I. zobellii and I. fontislapidosi). However, biochemical tests revealed that there were differences between the strains of the same species. Moreover, it was found that the ITS contains two tRNA genes, $tRNA^{Ile(GAT)}$ and $tRNA^{Ala(TGC)}$, which are separated by an ISR of a variable size between strains of I. zobellii. In one strain of I. zobellii (PM21), we found nonconserved nucleotides that were previously not reported in the $tRNA^{Ala}$ gene sequences of Idiomarina spp. Thus, based on the biochemical and molecular characteristics, we can conclude that protease producing Idiomarina strains have industrial potential; only two I. zobellii strains (PM48 and PM72) exhibited the same properties. The differences between the other strains could be explained by the presence of subspecies.

• Journal of Microbiology
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• 제44권6호
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• pp.607-616
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• 2006

Molecular characterization of ten marine cyanobacterial isolates belonging to the order Oscillatoriales was carried out using the phycocyanin locus (cpcBA-IGS) and the 16S-23S internally transcribed spacer region. DNA sequences from the phycocyanin operon discriminated ten genotypes, which corresponded to seven morphotypes identified by traditional microscopic analysis. The cpcB coding region revealed 17% nucleotide variation, while cpcA exhibited 29% variation across the studied species. Phylogenetic analyses support the conclusion that the Phormidium and Leptolyngbya genera are not monophyletic. The nucleotide variations were heterogeneously distributed with no or minimal informative nucleotides. Our results suggest that the discriminatory power of the phycocyanin region varies across the cyanobacterial species and strains. The DNA sequence analysis of the 16S-23S internally transcribed spacer region also supports the polyphyletic nature of the studied oscillatorian cyanobacteria. This study demonstrated that morphologically very similar strains might differ genotypically. Thus, molecular approaches comprising different gene regions in combination with morphological criteria may provide better taxonomical resolution of the order Oscillatoriales.

• 산업기술연구
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• 제28권A호
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• pp.141-147
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• 2008

Several contaminated bacteria such as Lactobacillus brevis and Pediococcus damnosus in beer production cause beer spoilage by producing off flavours and turbidity. Detection of these organisms is complicated by the strict anaerobic conditions and lengthy incubation times required for their cultivation, consequently there is a need for more rapid detection methods. Recently, two contaminated strains were isolated from vessel of beer production and identified as Lactobacillus species by API kit identificaton as well as 16S-23S ITS sequencing analyses. Two isolated strains were named as Lactobacillus sp. HLA1 and Lactobacillus HLB2, respectively. A polymerase chain reaction (PCR) method was developed for the rapid and specific detection of Lactobacillus sp.. Two sets of primer pairs (HLA1-F/HLA1-R and HLB2-F/HLB2-R) were designed for the amplification of a 1576 base pair (bp) fragment of the HLA1 16S-23S rRNA gene and 1888 bp fragement of the HLB2 16S-23S rRNA. Amplified PCR products were highly specific to detect corresponding bacteria when other contaminated strains were used as PCR templates. However, detection of both strains were limited when $100{\mu}{\ell}$ of cultured samples were mixed with $100m{\ell}$ of beer sample in arbitrary manner. The sensitivity of the assay still needs to be improved for direct detection of the small amounts of bacteria present in beer.

• Ocean Science Journal
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• 제41권4호
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• pp.315-318
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• 2006

Three Synechococcus strains were isolated from seawater near the Ieodo Ocean Research Station (IORS), and their 16S rDNA genes and the internal transcribed spacer (ITS) between the 16S and 23S rRNA genes were sequenced to investigate their phylogenetic relationships. Phylogenetic trees based on the 16S rDNA and ITS sequences showed that they clustered in the main MC-A Synechococcus group (subcluster 5.1), but formed branches differentiating them from the described clades. As the IORS is located in an area affected by diverse water masses, high Synechococcus diversity is expected in the area. Therefore, the IORS might be a good site to study the diversity, physiology, and distribution of the Synechococcus group.

• 한국미생물·생명공학회지
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• 제48권2호
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• pp.193-204
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• 2020

Sixteen acetic acid bacteria (AAB) were isolated from blueberries and citric fruits of the Salto Grande region (Concordia, Entre Rios, Argentina) using enrichment techniques and plate isolation. Enrichment broths containing ethanol and acetic acid enabled maximum AAB recovery, since these components promote their growth. Biochemical tests allowed classification of the bacteria at genus level. PCR-RFLP of the 16S rRNA and PCR-RFLP of the 16S-23S rRNA intergenic spacer allowed further classification at the species level; this required treatment of the amplified products of 16S and 16S-23S ITS ribosomal genes with the following restriction enzymes: AluI, RsaI, HaeIII, MspI, TaqI, CfoI, and Tru9I. C7, C8, A80, A160, and A180 isolates were identified as Gluconobacter frateurii; C1, C2, C3, C4, C5, C6, A70, and A210 isolates as Acetobacter pasteurianus; A50 and A140 isolates as Acetobacter tropicalis; and C9 isolate as Acetobacter syzygii. The bacteria identified by 16S rRNA PCR-RFLP were validated by 16S-23S PCR-RFLP; however, the C1 isolate showed different restriction patterns during identification and validation. Partial sequencing of the 16S gene resolved the discrepancy.

• ALGAE
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• 제39권2호
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• pp.59-74
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• 2024

Terrestrial cyanobacteria are extremely diverse. In urban areas, they can be found as black stains on the surface of building walls, stone monuments, or man-made structures. Many of the terrestrial cyanobacteria are still understudied. To expand knowledge of terrestrial cyanobacterial diversity, a polyphasic characterization was performed to identify 12 strains isolated from campus of University of the Ryukyus, Okinawa, Japan. Multigene phylogenetic analyses based on 16S rRNA gene and 16S-23S rRNA internal transcribed spacer (ITS) region showed that the isolated strains formed two independent subclades within Nodosilinea, and were distantly related to all described Nodosilinea species. The 16S-23S rRNA ITS secondary structures showed variations for D1-D1' and Box B domain, while V3 domain was almost identical among entire species of Nodosilinea, including the studied strains. In addition, a unique morphological character, i.e. forming nodule or spiral shape, was also observed in certain studied strains. According to polyphasic characterization, Nodosilinea coculeatus sp. nov. and Nodosilinea terrestrialis sp. nov., were proposed as two new species of terrestrial cyanobacteria from Okinawa.

• 동아시아경상학회지
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• 제6권3호
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• pp.16-23
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• 2018

Purpose - 2013 to 2014 was a transitional situation in which China's Smartphone industry was fluctuating. So in this paper, we will look at the strategies and achievements of Xiaomi, a company that has emerged in this situation and topped the market share. In particular, the purpose of this paper is to analyze why Xiaomi, which is considered a copycat, was able to succeed in the smartphone market four years after entering the market and analyze its strategy. Research design and methodology - Various secondary data are to be used for this study. Using various newspaper articles as well as corporate reports, the company analyzes the transitional situation from 2013 to 2014 and the competitors together. Through these analyses, Xiaomi's strengths are selected objectively and analyzed to identify the factors that made Xiaomi successful. Results - After China's transitional shift in 2014, Xiaomi brought about a 152.3 percent share change over the previous year. In addition, it surpassed Samsung Electronics, which has been the industry's No. 1 player, in 2014, and achieved the No. 1 ranking with a 16 percent share. Xiaomi Mi4's phone had a strong point of maintaining low price while being loaded with high performance. Conclusions - Xiaomi's success is because its price and performance was excellent. Xiaomi's Mi4's specifications were not far behind its competitors', but it was very cheap compared to its competitors' prices. They also valued software and used talent-oriented human resource strategies. Plus, it created the 'Mifan' culture successfully and benchmarked the strengths of its competitors smartly.

• 미생물학회지
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• 제55권1호
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• pp.1-8
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• 2019

Due to the major role played by several species of Streptococcus in the etiology of periodontitis, it is important to assess the pattern of Streptococcus pathogenic pathways within the infected subgingival pockets using a bacterial specific 16S rRNA fragment. From the total of 50 patients with periodontitis included in the study, only 23 Streptococcal isolates were considered for further analyses, in which their 16S rRNA fragments were amplified and sequenced. Then, a comprehensive phylogenetic tree was constructed and in silico prediction was performed for the observed Streptococcal species. The phylogenetic analysis of the subgingival Streptococcal species revealed a high discrimination power of the 16S rRNA fragment to accurately identify three groups of Streptococcus on the species level, including S. salivarius (14 isolates), S. anginosus (5 isolates), and S. gordonii (4 isolates). The employment of state-of-art in silico tools indicated that each Streptococcal species group was characterized with particular transcription factors that bound exclusively with a different 16S rRNA-based secondary structure. In conclusion, the observed data of the present study provided in-depth insights into the mechanism of each Streptococcal species in its pathogenesis, which differ in each observed group, according to the differences in the 16S rRNA secondary structure it takes, and the consequent binding with its corresponding transcription factors. This study paves the way for further interventions of the in silico prediction, with the main conventional in vitro microbiota identification to present an interesting insight in terms of the gene expression pattern and the signaling pathway that each pathogenic species follows in the infected subgingival site.

• 생명과학회지
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• 제34권9호
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• pp.639-646
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• 2024

본 연구에서는 Protaetia brevitarsis seulensis larvae 장내에서 서식하는 Bacillus 균주를 활용하여 프로바이오틱스 균주로 선발하기 위해 수행되었다. Bacillus 균주의 선발을 위해 Protaetia brevitarsis seulensis larvae로부터 유래된 균주를 80℃에서 10분간 가열한 후, 적절하게 희석하여 도달하여 성장하는 균주에 대해 일차적으로 carboxymethyl cellulase (CMCase) 활성에 의해 스크리닝한 후, 2차적으로 protease 활성에 의해 선발하였다. 선발된 균주 중에서 F23-72 균주가 CMCase 및 protease 활성이 매우 우수한 것으로 나타났다. 따라서 본 균주를 16S rDNA에 의해 동정을 실시하여 Bacillus velezensis F23-72로 명명하였다. F23-72는 CMCase, avicelase, cellobiase, xylanase, mannanase 등에 대해 B. velezensis KACC10334, K10과 유사한 활성을 보유한 것으로 나타났기 때문에 세포외 효소의 기능성이 우수한 것으로 판단된다. 자가 응집력은 L. plantarum K9에 비교하여 높은 반면에, B. velezensis에 비교하여 낮은 것으로 나타지만, 병원성 균주와 공응집력 및 mucin 부착력은 L. plantarum K9에 비교하여 낮은 것으로 나타났다. 따라서 이와 같은 특성은 Bacillus 균주들은 대체적으로 장점막에 부착성 및 병원성 세균을 부착하여 제거하는 기능은 낮은 것으로 추정된다. B. velezensis F23-72는 Staphylococcus aureus와 Salmonella Typhimurium에 대한 항균력이 KACC10334와 K10에 비교하여 약간 우수한 것으로 나타났으며, 각각 18과 24시간에서 가장 우수한 것으로 나타났다. 이상의 결과를 종합하면, B. velezensis F23-72는 세포외 효소 활성과 항균력이 우수한 반면에 점막 부착이나 병원성 균주의 제거 능력은 낮은 것으로 나타났기 때문에, 소화기능을 돕는 프로바이오틱스로써 활용 가능성이 제의된다.

• Journal of Microbiology and Biotechnology
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• 제23권6호
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• pp.739-749
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• 2013

The seasonal and spatial diversity of picocyanobacteria (Pcy) in lakes of the Great Mazurian Lakes (GLM) system was examined by DGGE analysis of molecular markers derived from the 16S-23S internal transcribed spacer (ITS) of the ribosomal operon and the phycocyanin operon (cpcBA-IGS). The study of nine lakes, ranging from mesotrophy to hypereutrophy, demonstrated seasonal variance of Pcy. The richness and Shannon diversity index calculated on the basis of both markers were higher in spring and lower in early and late summer. No statistically significant relationships were found between the markers and trophic status of the studied lakes or Pcy abundance. There were, however, statistically significant relationships between the diversity indices and sampling time. The analysis pointed to a different distribution of the two markers. The ITS marker exhibited more unique sequences in time and space, whereas a greater role for common and ubiquitous sequences was indicated by the cpcBA-IGS data. Examination of the Pcy community structure demonstrated that communities were grouped in highly similar clusters according to sampling season/time rather than to the trophic status of the lake. Our results suggest that time is more important than trophic status in shaping the diversity and structure of Pcy communities. The seasonal changes in picocyanobacteria and differences in diversity and community structures are discussed in the context of well-established ecological hypotheses: the PEG model, intermediate disturbance hypothesis (IDH), and horizontal gene transfer (HGT).