• Journal of the East Asian Society of Dietary Life
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• v.15 no.4
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• pp.444-449
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• 2005

Effect of salt concentration on the quality of Saewoojeot (salted shrimp) fermented at room temperature was evaluated Salted shrimp with three different salt concentration (9, 18 and $27\%$) were prepared with fresh shrimp, and fermented at $20^{\circ}C$ temperatures for 180 days. Amino nitrogen (AN), volatile basic nitrogen (VBN) and trimethylamine (TMA) contents increased with longer fermentation time and lower salt concentration. AN, VBN and TMA contents in salted and fermented shrimp with $9\%$ salt increased rapidly during fermentation period, while that with 18 and $27\%$ salt maintained its initial level through 180 days of fermentation. When salted and fermented shrimps were fermented at $20^{\circ}C$, all the indexes of fermentation process maintained stable with $27\%$ salt level. Pathogenic bacteria such as pathogenic Echerichia coli, Salmonella spp., were not detected in the manufactured salted and fermented shrimps. However, coliform and yeast disappeared within 180 days and 100 days of storage for 18 and $27\%$ salt, respectively. Gram positive cocci survived until 180 days of storage against $18\%$($10^3-10^6$ CFU/g) and $27\%$($0-10^6$ CFU/g) salt.

• Bulletin of the Korean Chemical Society
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• v.28 no.8
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• pp.1335-1340
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• 2007

β-Ketoacyl acyl carrier protein synthase (KAS) III is a particularly attractive target in the type II fatty acid synthetic pathway, since it is central to the initiation of fatty acid synthesis. Enterococcus faecalis, a Grampositive bacterium, is one of the major causes of hospital acquired infections. The rise of multidrug-resistant of most bacteria requires the development of new antibiotics, such as inhibition of the KAS III. In order to block the fatty acid synthesis by inhibition of KAS III, at first, three dimensional structure of Enterococcus faecalis KAS III (efKAS III) was determined by comparative homology modeling using MODELLER based on x-ray structure of Staphylococcus aureus KAS III (saKAS III) which is a gram-positive bacteria and is 36.1% identical in amino acid sequences with efKAS III. Since His-Asn-Cys catalytic triad is conserved in efKAS III and saKAS III, substrate specificity of efKAS III and saKAS III and the size of primer binding pocket of these two proteins are expected to be similar. Ligand docking study of efKAS III with naringenin and apigenin showed that naringenin docked more strongly with efKAS III than apigenin, resulting in the intensive hydrogen bond network between naringenin and efKAS III. Also, only naringenin showed antibacterial activity against E. faecalis at 256 μg/mL. This study may give practical implications of flavonoids for antimicrobial effects against E. faecalis.

• Clean Technology
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• v.13 no.1 s.36
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• pp.22-27
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• 2007

Pacquer traditionally has been used to varnish. Many reports have revealed that lacquer has durability and antimicrobial activities. Therefore, we expect that lacquer will be used as a good antifouling agent to solve the environmental problem. Here we chemically synthesized urushiol, a major component in lacquer and two urushiol derivatives, urusiol regioisomer and cardanol. We also analyzed the antimicrobial activities of these molecules to examine the inhibitory effect on the formation of the biofilms. Our results showed that synthesized urushiol and its derivatives have strong antifungal activities. Urushiol also exhibited inhibitory effect on the growth of gram positive bacteria specifically. However urushiol derivatives have low antibacterial activities.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.71-76
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• 1998

The effects of chitosan on mastitis in lactating holstein cows were evaluated. Fifty six cows with intramammary infection(IMI) from nine farms were selected and the cows were fed with diets which contained 15~20g chitosan per day for 5~7 days. The milk samples were obtained from cows at 7 days and 14 days after administration to determine effect of the curing of mastitis and the reduction of somatic cell counts(SCC). The average value of SCC levels in quarter milk from the cows administrated with chitosan significantly decreased up to 31.8% and 47.7% at 7 and 14 days, respectively(P<0.05). The cure rates of chitosan for Stapylococcus aureus, coagulase-negative Staphylococci, Streptococci spp, other gram positive bacteria and coliforms were 30.4, 42.8, 33.3, 66.6 and 54.5 % respectively. Twenty three out of 64 cases were cured by feeding with chitosan. The results showed that administration of chitosan could reduce SCC in milk and improve cure rates of bovine mastitis caused by microorganisms. The further studies will be pursued to study on the mechanism of chitosan in the immune responses of cows with mastitis.

• Food Science of Animal Resources
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• v.35 no.5
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• pp.683-691
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• 2015

The objective of this study was to identify the coccoidal bacteria present in 188 samples of fermented yaks’, mares’ and cows’ milk products collected from 12 different regions in Mongolia. Furthermore, we evaluated the fermentation properties of ten selected isolates of the predominant species, Streptococcus (S.) thermophiles, during the process of milk fermentation and subsequent storage of the resulting yoghurt at 4℃. Overall, 159 isolates were obtained from 188 samples using M17 agar. These isolates were presumed to be lactic acid bacteria based on their gram-positive and catalase-negative properties, and were identified to species level using 16S rRNA gene sequence analysis. These coccoid isolates were distributed in four genera and six species: Enterococcus (E.) durans, Enterococcus (E.) faecalis, Lactococcus (Lac.) subsp. lactis, Leuconostoc (Leuc.) lactis, Leuconostoc (Leuc.) mesenteroides. subsp. mesenteroides and S. thermophilus. Among these S. thermophilus was the most common species in most samples. From evaluation of the fermentation characteristics (viable counts, pH, titratable acidity [TA]) of ten selected S. thermophilus isolates we could identify four isolates (IMAU 20246, IMAU20764, IMAU20729 and IMAU20738) that were fast acid producers. IMAU20246 produced the highest concentrations of lactic acid and formic acid. These isolates have potential as starter cultures for yoghurt production.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.1035-1038
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• 2005

Yacon (Polymnia sonchifolia Poepping & Endlicher), which contains fructo-oligosaccharide, is low calorie functional food. Yacon is efficacious against cholesterol, obesity, and diabetes. Yacon K-23 has antibacterial activity against Gram-positive (Listeria monocytogenes KCTC 3710 and Staphylococcus aureus KCTC 1927) and negative (Salmonella typhimurium KCTC 2514, Escherichia coli KCCM 11591, Proteus vulgaris KCTS 2512, and Pseudomonas aeruginosa KCCM 11803), Yacons A (water extract) and B (crushed juice) showed clear zone of 10mm, while Cassiae Semen, Acanthopanacis Cortex, Angelica gigas showed 7-10mm. Yacon jam showed good sensory attributes, suggesting it could be utilized as food ingredient. Hardness, adhesiveness, and strength of strawberry jam with or without aloe vera were higher than those of yacon jam with or without aloe vera.

• Korean Journal of Medicinal Crop Science
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• v.24 no.3
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• pp.222-227
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• 2016

Background: The biological activities of Tradescantia pallida grown in Korea have not been well determined, thus the aim of this study was to investigate the possibility of using it as a medicinal plant. Methods and Results: To investigate the antioxidant activity, ${\alpha}$-glucosidase inhibitory effect and antimicrobial activity of T. pallida, we performed the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and reducing power assay. This assay for T. pallida leaf extract showed the highest antioxidant activity for the ethyl acetate fraction ($RC_{50}=14.55{\pm}0.16{\mu}g/m{\ell}$ and Abs = 0.613 at $300{\mu}g$). Further, the ethyl acetate fraction exhibited higher ${\alpha}$-glucosidase inhibitory effect with an $IC_{50}$ value of $14.1{\pm}0.1{\mu}g/m{\ell}$ and showed antimicrobial activity against gram positive bacteria (minimum inhibitory concentration = $1,000{\mu}g/m{\ell}$). Conclusions: The ethyl acetate fraction of the crude methanol extract of T. pallida showed remarkable antioxidant activity, ${\alpha}$-glucosidase inhibitory effects and antimicrobial activity. These activities might be related to the flavonoid content in the T. pallida leaf extract.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.475-480
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• 2010

Actinomycetes are Gram-positive soil bacteria and one of the most important industrial microorganisms due to superior biosynthetic capabilities of many valuable secondary metabolites as well as production of various valuable bioconversion enzymes. Among them are cytochrome P450 hydroxylase (CYP), which are hemoproteins encoded by a super family of genes, are universally distributed in most of the organisms from all biological kingdoms. Actinomycetes are a rich source of soluble CYP enzymes, which play critical roles in the bioactivation and detoxification of a wide variety of metabolite biosynthesis and xenobiotic transformation. Cyclosporin A (CyA), one of the most commonly-prescribed immunosuppressive drugs, was previously reported to be hydroxylated at the position of 4th N-methyl leucine by a rare actinomycetes called Sebekia benihana, leading to display different biological activity spectrum such as loss of immunosuppressive activities yet retaining hair growth-stimulating side effect. In order to improve this regio-selective CyA hydroxylation in S. benihana, previously-identified several secondary metabolite up-regulatory genes from Streptomyces coelicolor and S. avermitilis were heterologously overexpressed in S. benihana using an $ermE^*$ promoter-containing Streptomyces integrative expression vector. Among tested, SCO4967 encoding a conserved hypothetical protein significantly stimulated region-specific CyA hydroxylation in S. benihana, implying that some common regulatory systems functioning in both biosynthesis and bioconversion of secondary metabolite might be present in different actinomycetes species.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.263-272
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• 2010

One hundred sixty three strains showing different colony morphological characteristics on different concentration of marine agar (MA) plates were isolated from ambient seawater near Dokdo island. Bacterial diversity and distributions were studied by phylogenetic analysis of the partial 16S rRNA gene sequences. One hundred sixty three strains were partially sequenced and analyzed phylogenetically. They were composed of 5 phyla, of which gamma-proteobacteria (58%), alpha-proteobacteria (20%), bacteriodetes (16%) were predominant. They were affiliated with 90 species. The 16S rRNA sequence similarity of the isolates was in 93.3 to 100 % range to reported sequence data. Thirty six isolates of among them were assumed to be novel species candidates based on similarity analysis of the 16S rRNA gene sequences. Overall, Proteobacteria and Bacteriodetes of the Dokdo coastal sea water showed a high diversity.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.352-359
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• 2012

One hundred thirty-four putative Bacillus isolates were recovered from soybean rhizosphere soils of Nimar region to select effective zinc solubilizers for increased assimilation of zinc (Zn) in soybean seeds. These isolates were screened in vitro for zinc-solubilization ability on Tris-minimal agar medium supplemented separately with 0.1% zinc in the form of zinc oxide, zinc phosphate, and zinc carbonate. Of all, 9 isolates and a reference Bacillus cereus ATCC 13061 were characterized and identified as Bacillus species based on Gram-positive reaction, endospore-forming cells, and the presence of iso-$C_{15:0}$ and anteiso-$C_{15:0}$ as predominant fatty acids. On plate assay, two isolates KHBD-6 and KHBAR-1 showed a greater diameter of solubilization halo and colony diameter on all the three zinc compounds. The isolates KHBD-6, KHBAR-1, BDSD-2-2C, and KHTH-4-1 and the reference strain ATCC 13061 had higher soluble zinc concentration in liquid medium supplemented with zinc phosphate and zinc carbonate compounds as compared with the other isolates and uninoculated control. Evaluation under microcosm conditions showed that inoculation of isolates KHBD-6 (57.34 ${\mu}g/g$), KHBAR-1 (55.67 ${\mu}g/g$), and strain ATCC 13061 (53.10 ${\mu}g/g$) significantly increased the Zn concentration in soybean seeds as compared with the other isolates and uninoculated control (47.14 ${\mu}g/g$). This study suggests the occurrence of zinc-solubilizing Bacillus in soils of Nimar region and isolates KHBD-6 and KHBAR-1 were found to be promising zinc solubilizers for increased assimilation of Zn in soybean seeds.