• 제목/요약/키워드: Natural Sciences and Engineering's College

검색결과 155건 처리시간 0.027초

Identification of Two Entomopathogenic Bacteria from a Nematode Pathogenic to the Oriental Beetle, Blitopertha orientalis

  • Yi, Young-Keun;Park, Hae-Woong;Shrestha, Sony;Seo, Ji-Ae;Kim, Yong-Ook;Shin, Chul-Soo;Kim, Yong-Gyun
    • Journal of Microbiology and Biotechnology
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    • 제17권6호
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    • pp.968-978
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    • 2007
  • A pathogenic nematode, Butlerius sp., was isolated from Oriental beetle, Blitopertha orientalis. The infective juveniles exhibited dose-as well as time-dependent entomopathogenicity on the larvae of B. orientalis. Two bacterial species, Providencia vermicola (KACC 91278) and Flavobacterium sp. (KACC 91279), were isolated from the infective juveniles and identified. P. vermicola outnumbered Flavobacterium sp. in the nematode host, in which the colony density of P. vermicola was found to be 21 times higher than that of Flavobacterium sp. However, when the two bacterial species were cocultured in culture media without the nematode host, they showed similar growth rates. Both bacteria induced significant entomopathogenicity against Spodoptera exigua larvae infesting economically important vegetable crops, where P. vermicola was more potent than Flavobacterium sp.

Modulation of Inflammatory Pathways and Adipogenesis by the Action of Gentisic Acid in RAW 264.7 and 3T3-L1 Cell Lines

  • Kang, Min-jae;Choi, Woosuk;Yoo, Seung Hyun;Nam, Soo-Wan;Shin, Pyung-Gyun;Kim, Keun Ki;Kim, Gun-Do
    • Journal of Microbiology and Biotechnology
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    • 제31권8호
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    • pp.1079-1087
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    • 2021
  • Gentisic acid (GA), a benzoic acid derivative present in various food ingredients, has been shown to have diverse pharmaceutical activities such as anti-carcinogenic, antioxidant, and hepatoprotective effects. In this study, we used a co-culture system to investigate the mechanisms of the anti-inflammatory and anti-adipogenic effects of GA on macrophages and adipocytes, respectively, as well as its effect on obesity-related chronic inflammation. We found that GA effectively suppressed lipopolysaccharide-stimulated inflammatory responses by controlling the production of nitric oxide and pro-inflammatory cytokines and modulating inflammation-related protein pathways. GA treatment also inhibited lipid accumulation in adipocytes by modulating the expression of major adipogenic transcription factors and their upstream protein pathways. Furthermore, in the macrophage-adipocyte co-culture system, GA decreased the production of obesity-related cytokines. These results indicate that GA possesses effective anti-inflammatory and anti-adipogenic activities and may be used in developing treatments for the management of obesity-related chronic inflammatory diseases.

Kluyverromyces fragilis의 Alkaline Phosphatase 유전자의 구조 분석 (Structural Analysis of Alkaline Phosphatase Gen from Kluyveromyces Fragilis)

  • 박수영;황선갑;하상철;김종국;박완;홍순덕
    • 한국미생물·생명공학회지
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    • 제22권1호
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    • pp.31-36
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    • 1994
  • From the pSKH201 plasmid which had been previously cloned in our laboratory, a 3.0kbp insert DNA encoding the alkaline phosphatase of Kluyveromyces fragilis was cleaved with several restriction endonucleases and ligated int the appropriate sites of M13mp18/19 vectors and sequenced by Sanger's dideoxy chain termination method. The sequence contained a 1,638 bp open reading frame(ORP) whose similarities in nucleotide, when compared with those of Saccharomyces cerevisiae and Escherichia coli by GENETYX program, were found to be 61% and 46%, respectively. The deduced amino acid sequence consists of 546 amino acids and contains several homologous regions in the alkaline phosphatases of E. coli, S.cerevisiae and human placenta.

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Molecular Cloning and Functional Expression of esf Gene Encoding Enantioselective Lipase from Serratia marcescens ES-2 for Kinetic Resolution of Optically Active (S)-Flurbiprofen

  • Lee, Kwang-Woo;Bae, Hyun-Ae;Lee, Yong-Hyun
    • Journal of Microbiology and Biotechnology
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    • 제17권1호
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    • pp.74-80
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    • 2007
  • An enantioselective lipase gene (esf) for the kinetic resolution of optically active (S)-flurbiprofen was cloned from the new strain Serratia marcescens ES-2. The esf gene was composed of a 1,845-bp open reading frame encoding 614 amino acid residues with a calculated molecular mass of 64,978 Da. The lipase expressed in E. coli was purified by a three-step procedure, and it showed preferential substrate specificity toward the medium-chain-length fatty acids. The esf gene encoding the enantioselective lipase was reintroduced into the parent strain S. marcescens ES-2 for secretory overexpression. The transformant S. marcescens BESF secreted up to 217kU/ml of the enantioselective lipase, about 54-fold more than the parent strain, after supplementing 3.0% Triton X-207. The kinetic resolution of (S)-flurbiprofen was carried out even at an extremely high (R,S)-flurbiprofen ethyl ester [(R,S)-FEE] concentration of 500 mM, 130 kU of the S. marcescens ES-2 lipase per mmol of (R,S)-FEE, and 1,000 mM of succinyl ${\beta}-cyclodextrin$ as the dispenser at $37^{\circ}C$ for 12h, achieving the high enantiomeric excess and conversion yield of 98% and 48%, respectively.

Engineering of Sulfolobus acidocaldarius for Hemicellulosic Biomass Utilization

  • Lee, Areum;Jin, Hyeju;Cha, Jaeho
    • Journal of Microbiology and Biotechnology
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    • 제32권5호
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    • pp.663-671
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    • 2022
  • The saccharification of cellulose and hemicellulose is essential for utilizing lignocellulosic biomass as a biofuel. While cellulose is composed of glucose only, hemicelluloses are composed of diverse sugars such as xylose, arabinose, glucose, and galactose. Sulfolobus acidocaldarius is a good potential candidate for biofuel production using hemicellulose as this archaeon simultaneously utilizes various sugars. However, S. acidocaldarius has to be manipulated because the enzyme that breaks down hemicellulose is not present in this species. Here, we engineered S. acidocaldarius to utilize xylan as a carbon source by introducing xylanase and β-xylosidase. Heterologous expression of β-xylosidase enhanced the organism's degradability and utilization of xylooligosaccharides (XOS), but the mutant still failed to grow when xylan was provided as a carbon source. S. acidocaldarius exhibited the ability to degrade xylan into XOS when xylanase was introduced, but no further degradation proceeded after this sole reaction. Following cell growth and enzyme reaction, S. acidocaldarius successfully utilized xylan in the synergy between xylanase and β-xylosidase.

햄스터 망막에서의 광수용체 분포 (Populations of Rod and Cone Photoreceptors in the Hamster Retina)

  • 유성희;김현진;이경필;이은실;이제영;전창진
    • Applied Microscopy
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    • 제39권4호
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    • pp.291-299
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    • 2009
  • 본 연구에서는 햄스터 망막의 추상과 간상 광수용체의 양적 분석을 하였다. 추상 광수용체를 과산화 효소로 표지된 피넛 렉틴(peroxidase-labeled peanut lectin)을 사용하여 염색한 뒤 광학 미분간섭 현미경(DIC, differential interference contrast optics)을 사용하여 관찰하였다. 또한 면역세포화학적 방법으로 추상 광수용체에 위치한 M/L-옵신과 S-옵신을 염색한 뒤 공초점 형광 현미경(confocal microscope)을 사용하여 관찰하였다. 추상세포의 평균 밀도는 9,307 $cells/mm^2$이며 전체 추상세포는 293,060개였다. 추상세포의 최대값(12,857 $cells/mm^2$)은 맹점(시신경 유두, optic disk)로부터 코 쪽 망막(nasal retina)으로 0.3 mm 떨어진 곳에 위치하였다. 간상세포의 평균은 300,082 $cells/mm^2$으로 전체 간상세포는 9,448,150개였다. 간상세포의 최대값(340,000 $cells/mm^2$)은 맹점으로부터 등쪽 망막(dorsal retina) 방향으로 0.3 mm 떨어진 곳에서 발견되었다. 평균적으로 전체 광수용체 중, 간상세포의 전체 분포는 96.99%이고 추상세포는 3.01%를 차지하였다. 또한 간상과 추상의 평균 비는 32.24 : 1이었다. 햄스터의 추상세포는 M/L-와 S-옵신을 가진다. 본 연구 결과는 햄스터가 일부 명소시를 가지는 강한 간상 우세 망막임을 제시한다.