Publications by authors named "Sang-Hong Yoon"

Article Synopsis
  • * The nasYPL gene, which is 903 bp long, has similarities to a hypothetical protein from another bacterium, Massilia niastensis, and falls under Group 1 NAS based on phylogenetic analysis.
  • * When nasYPL was expressed in Escherichia coli and two Pseudomonas strains, it demonstrated antibacterial properties against several harmful bacteria, producing various N-acyl derivatives that could be useful in biotechnology.
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A novel pullulanase gene, PulSS4, was identified from the gut microflora of Hermetia illucens by a function-based metagenome screening. The PulSS4 gene had an open reading frame of 4455 base pairs, and encoded a mature protein of 1484 amino acids, with a signal peptide sequence of 44 amino acids. The deduced amino acid sequence of PulSS4 gene showed 51% identity with that of the amylopullulanase of Amphibacillus xylanus, exhibiting no significant sequence homology to already known pullulanases.

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A metagenomic fosmid library was constructed using genomic DNA isolated from the gut microflora of Hermetia illucens, a black soldier fly. A cellulase-positive clone, with the CS10 gene, was identified by extensive Congo-red overlay screenings for cellulase activity from the fosmid library of 92,000 clones. The CS10 gene was composed of a 996 bp DNA sequence encoding the mature protein of 331 amino acids.

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A functional screen of a metagenomic library from "Upo" swamp sediment in Korea identified a gene EstL28, the product of which displayed lipolytic properties on a tributyrin-supplemented medium. The EstL28 sequence encodes a 290 amino acid protein (designated as EstL28), with a predicted molecular weight of 31.3 kDa.

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A novel, Gram-negative, bacterial strain KIS30-44(T) was identified from wet forest soil collected on the Korean island of Dokdo. Growth of the strain was observed at 15-30°C, pH 5-9, 0-3% NaCl, and 950 mM KNO(3). KIS30-44(T) reduced nitrate to nitrogen gas.

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It has been proposed that family VIII carboxylesterases and class C β-lactamases are phylogenetically related; however, none of carboxylesterases has been reported to hydrolyze β-lactam antibiotics except nitrocefin, a nonclinical chromogenic substrate. Here, we describe the first example of a novel carboxylesterase derived from a metagenome that is able to cleave the amide bond of various β-lactam substrates and the ester bond of p-nitrophenyl esters. A clone with lipolytic activity was selected by functional screening of a metagenomic library using tributyrin agar plates.

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A novel bacterium, designated strain 5YN1-3(T), was isolated from wetland peat collected from Yongneup, Korea. The bacterium was facultatively anaerobic, Gram-negative, yellow-coloured, rod-shaped, mesophilic and motile with one polar flagellum. The strain grew optimally at 30 degrees C, at pH 6.

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There are several conditions which might modulate polymerization to produce polymers having normal lattice structure. In the absence of 1 mM MgCl(2) the assembly was reduced by 36% in Capsicum annuum tubulin (CAnm tubulin). There was no significant difference in the final assembly formation in the presence of 5% to 10% glycerol.

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Internal fragments of alpha- and beta-tubulin genes were generated using reverse transcription polymerase chain reaction (RT-PCR), and the termini were isolated using 5'- and 3'-rapid amplification of cDNA ends. Phytophthora capsici alpha- and beta-tubulin specific primers were then used to generate full-length cDNA by RT-PCR. The recombinant alpha- and beta-tubulin genes were expressed in Escherichia coli BL21 (DE3), purified under denaturing conditions, and average yields were 3.

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4-Hydroxyphenylpyruvate dioxygenase (HPPD) is a Fe(II)-dependent, non-heme oxygenase that converts 4-hydroxyphenylpyruvate to homogentisate. Essential cofactors, such as plastoquinone and tocopherol, are produced by HPPD-dependent anabolic pathways in plants. To isolate a novel hppd using culture-independent method, a cosmid metagenomic library was constructed from soil in Korea.

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To detect cellulases encoded by uncultured microorganisms, we constructed metagenomic libraries from Korean soil DNAs. Screenings of the libraries revealed a clone pCM2 that uses carboxymethyl cellulose (CMC) as a sole carbon source. Further analysis of the insert showed two consecutive ORFs (celM2 and xynM2) encoding proteins of 226 and 662 amino acids, respectively.

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Two bacterial strains isolated from air samples, 5317S-33(T) and 5413S-11(T), were characterized by determining their phenotypic characteristics, cellular fatty acid profiles and phylogenetic positions based on 16S rRNA gene sequence analysis. 16S rRNA gene sequence analysis showed that these isolates belonged to the genus Methylobacterium. Strain 5317S-33(T) was most closely related to Methylobacterium adhaesivum AR27(T) (97.

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A novel beta-glucosidase gene, bglA, was isolated from uncultured soil bacteria and characterized. Using genomic libraries constructed from soil DNA, a gene encoding a protein that hydrolyzes a fluorogenic analog of cellulose, 4-methylumbelliferyl beta-D-cellobioside (MUC), was isolated using a microtiter plate assay. The gene, bglA, was sequenced using a shotgun approach, and expressed in E.

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The effect of surfactin on the proliferation of LoVo cells, a human colon carcinoma cell line, was examined. Surfactin strongly blocked the proliferation of LoVo cells by inducing pro-apoptotic activity and arresting the cell cycle, according to several lines of evidence on DNA fragmentation, Annexin V staining, and altered levels of poly (ADP-ribose) polymerase, caspase-3, p21(WAF1/Cip1), p53, CDK2 and cyclin E. The anti-proliferative activity of surfactin was mediated by inhibiting extracellular-related protein kinase and phosphoinositide 3-kinase/Akt activation, as assessed by phosphorylation levels.

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Among Pseudomonas strains isolated from Korean agricultural soils, four strains (Ps 9-14 group: Ps 1-2, Ps 1-10, Ps 5-5 and Ps 9-14T) from the Suwon, Goesan and Samchok regions, three strains (Ps 3-10 group: Ps 2-22, Ps 3-1 and Ps 3-10T) from Umsong Region and four strains (Pss 26 group: Pss 14, Pss 25, Pss 26T and Pss 27) from Jinju Region were identified as three independent groups on the basis of 16S rDNA sequence analysis. While, on the basis of 16S rDNA sequence analysis, Ps 9-14T and Ps 3-10T form a phyletic line with Pseudomonas jessenii CIP 105274T, 'Pseudomonas pavonaceae' IAM 1155 and Pseudomonas graminis DSM 11363T, Pss 26T is grouped with Pseudomonas citronellolis ATCC 13674T and Pseudomonas nitroreducens IAM 1439T. According to DNA-DNA hybridization studies, strain Ps 9-14T shows high DNA relatedness to strain Ps 3-10T (52%) and Pseudomonas migulae CIP 105470T (49%) and strain Ps 3-10T reveals high relatedness to strain Ps 9-14T (48%) and P.

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