• The Korean Journal of Mycology
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• v.34 no.2
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• pp.92-97
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• 2006

The liquid culture extract of Coriolus versicolor was prepared by directly boiling the whole culture broth 7 days after incubation in 12% citrus extract medium. After removal of mycelial debris through filtration, this extract was further extracted with equal volume of ethyl acetate (1 : 1, v/v). The ethyl acetate extracts showed significant antibacterial activities against Stapylococcus aureus CCARM3230 and Psudomonas aeruginosa CCARM2171, which are resistant to several antibiotics. The most active fraction was eluted from a silica gel column with a mixture of dichloromethane and methanol (9 : 1, v/v) and the purity of this active substance was confirmed by HPLC analysis. The results suggest that the purified active substance could be a good source for the development of a new antimicrobial agent, especially for the treatment of antibiotic resistant bacteria.

• The Korean Journal of Mycology
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• v.44 no.3
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• pp.138-144
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• 2016

Twelve unrecorded yeasts, Pseudozyma prolifica HL9-1, Trichosporon coremiiforme NS19-2, Candida cretensis SA4-1, Cryptococcus diffluens TJ4-3, Cryptococcus pinus YB17-2, Candida vartiovaarae DD2-5, Pichia galeiformis DM3-5, Candida pseudolambica JW2-3, Trichosporon xylopini NS5-1, Trichosporon moniliiforme NS5-7, Tetrapisispora iriomotensis NS14-2, and Tetrapisispora nanseiensis SA17-1, were screened among 97 yeasts from soils of Chungcheongnam-do and Daejeon metropolitan city, Korea. These yeasts were oval or ellipsoidal and had a budding system for vegetative reproduction. They grew well in yeast extract-peptone-dextrose (YPD) medium and, in particular, Tetrapisispora iriomotensis NS14-2 and Candida cretensis SA4-1 grew well in 10% NaCl-containing YPD broth. Nine strains, including Trichosporon coremiiforme NS19-2, assimilated xylose and four yeast strains, such as Candida vartiovaarae DD2-5, also assimilated lactose. Physiological functionalities of cell-free extracts and supernatants from two halophilic unrecorded yeasts, Candida cretensis SA4-1 and Tetrapisispora iriomotensis NS14-2, were investigated. Cell-free extracts from Candida cretensis SA4-1 and Tetrapisispora iriomotensis NS14-2 exhibited 71.3% and 68.4% antihypertensive angiotensin I-converting enzyme inhibitory activity.

• The Korean Journal of Mycology
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• v.46 no.1
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• pp.75-82
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• 2018

Totally 91 strains of wild yeasts were isolated from the humus rich soil in the Bogyong city park of Daejeon city, Korea. Majority of the strains belonged to Cryptococcus spp., which included 11 strains of Cryptococcus aureus. Among them, Kwoniella mangroviensis JSS0500, Candida corydalis JSS0501, Candida bombi JSS0503, Candida multigemmis JSS0504, Cryptococcus dimennae JSS0506, Cryptococcus saitoi JSS0507, Cryptococcus victoriae JSS0508, Metschnikowia pulcherrima JSS0502, Papiliotrema aurea JSS0505, Debaryomyces vanrijia JSS0509, Occultifur externus JSS0510, Filobasidium floriforme JSS0511 and Yamadazyma scolyti JSS0512 represented newly recorded yeast strains in Korea, and their microbiological characteristics were investigated. All of these unrecorded yeasts showed oval shape and also formed ascospores and pseudomycelia, except for Kwoniella mangroviensis JSS0500, Candida bombi JSS0503, and Metschnikowia pulcherrima JSS0502. Seven strains including Candida corydalis JSS0501 grew in vitamin-free medium, and 4 of the wild yeasts including Cryptococcus victoriae JSS0508 were halotolerant, i.e., capable of growing in 10% NaCl-containing yeast extract-peptone-dextrose (YPD) broth. Debaryomyces vanrijia JSS0509 was found to be a thermophilic yeast that grew at $37^{\circ}C$.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.3
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• pp.47-66
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• 1999

We have tried to measure the anti-dandruff effect of the several kinds of formulations by determining the MIC values of the P. ovale which was determined by resazurin(alarmar Blue$^{TM}$). To get high reproducibility, it was suggested that about 2.6$\times$10$^{5}$ cfu/$m\ell$ of P ovate should be incubated with alarmar Blue$^{TM}$, optimum dilution ratio between alarmar Blue$^{TM}$ and PBS buffer should be 1:1 -1:4, and optimum incubation time should be 16 ~ 24 hours. Even though 1:1 diluted alarmar Blue$^{TM}$ was incubated with P ovale, the metabolic activity of if ovule was not inhibited by alarmar BlueTM. The Minimum Inhibitory Concentration(MIC) values of several kinds of anti-dandruff formulation which were the mixture system between Zinc pyrithione and Climbazole make it possible to determine the optimal anti-dandruff formulation, which show similar results with that of microscopic MIC determination and that of SDDM(Skin-Disk Diffusion Method). It is expected that the anti-dandruff test method which uses alarmar Blue$^{TM}$ could be used as an effective in vitro test method because it was not so much affected by the turbidity of the broth and samples, and it can afford the MIC values of many samples within relatively short time by using microplate reader.te reader.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.752-755
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• 2003

The antimicrobial activity of fresh garlic juice against Escherichia coli O157:H7 was investigated. When E. coli O157:H7 was cultured for 18 hr in the trypticase soy broth containing 1%, 3%, and 5% garlic juice, viable cell number of E. coli O157:H7 was reduced to $2.3{\times}10^2\;CFU/mL$ at 5% from $7{\times}10^8\;CFU/mL$ at the non-treated culture, respectively. The inhibitory effects of the ground beef treated with 3%, 6%, and 10% garlic juice against E. coli O157:H7 was significantly enhanced with approximate 2 log-reduction compared to that of ground beef without garlic. There was no significant difference in the inhibition of E. coli O157:H7 among the groups with different amounts of garlic juice (p<0.05). These results suggest that garlic juice may function well as a natural preservative in food system.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.488-492
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• 2012

Two strains, traditionally referred to as rock flower (Bawhi-kot) and buckwheat flower (Memil-kot or Chile-Kot), were isolated from stored traditional soy sauce and were identified by using the 18S ITS1/4 region sequences. The rock flower strain showed 99% of similarity with Cladosporium sp. and buckwheat flower strain was 99% identical with yeast Sterigmatomyces halophilus. Both strains were tentatively named Cladosporium sp. NK1 and Sterigmatomyces halophilus NK2, respectively. The optimal growth pHs and temperatures of both strains in a YPD broth medium were in the range of pH 5.0 to 7.0 and 22 to $27^{\circ}C$. Both strains were able to grow in more than 20% of NaCl. In the enzyme activity assay, high protease activity of Cladosporium sp. NK1 and S. halophilus NK2 were obtained in YPD containing 10% of NaCl. High amylase activities of both stains were in 15% and 5% of NaCl, respectively. Lipase activity was, however, not detected in both strains.

• Journal of Life Science
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• v.17 no.10
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• pp.1434-1440
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• 2007

We have investigated the effects of mushroom mycelium (Phellinus linteus, Coriolus versicolor) mixed cultural extract on the immune responses of olive flounder, Paralichthys olivaceus. The mixed culture extracts were evaluated for the growth, hematology, lysozyme activity, leukocyte phagocytic activity, and disease resistance against Vibrio anguillarum. In the effect of the growth, the body weight and length gain in the group, which fed with mushroom mycelium mixed cultural extract, were 52 g and 3.4 cm higher than that in the control, respectively. For the hematology, the administration of mushroom mycelium mixed cultural extract resulted in increase of glucose. However, there was no distinct differences in GOT (glutamic oxaloacetic transaminase), GPT (glutamlc pyruvic transamlnase), TG, TP, and LDH (lactate dehydronase) among each group. The activities of lysozyme were 80% higher in the experimental groups than in the control. The activities of leucocyte were 66% higher in the experimental groups than in the control. Although lysozyme activity and leucocyte activity showed somewhat decrease after 12 weeks, these activities were still higher than in the control. The cumulative mortality (%) after an artificial challenge with $7{\times}10^8\;CFU$ of Vibrio anguillarum per fish was 25% higher in the experimental groups than the control.

• Journal of Life Science
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• v.21 no.1
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• pp.68-73
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• 2011

$\beta$-1,3-glucanase from Pyrococcus furiosus was applied for the saccharification of laminarin, which is a major oligo-saccharide component of brown algae, and the reaction mixture produced from laminarin was utilized as a substrate for alcohol fermentation using yeast. To prepare the recombinant $\beta$-1,3-glucanase, a $\beta$-1,3-glucanase gene was overexpressed in Escherichia coli and purified. Laminarin was degraded to an oligo- and mono-saccharide, such as glucose, after reaction with the purified recombinant $\beta$-1,3-glucanase, and the products after enzymatic treatment were confirmed by TLC and HPLC analysis. Decomposed laminarin after enzyme reaction was only added to the medium as a C-source for yeast alcohol production reaction. 0.3% alcohol production was detected from the cultured broth by gas chromatography after 48 hr of incubation. Further evaluation for optimal conditions of saccharification and alcohol fermentation can be suggested, as well as the possibility of using this enzymatic method to produce ethanol using laminarin.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.166-172
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• 2006

Metallo-${\beta}$-lactamase (MBL) can hydrolyze all ${\beta}$-lactams except monobactams and frequently coexists with various antibiotic resistance genes such as aminoglycoside resistance, sulfonamide resistance gene, etc. Therefore, the effective antibiotics against infections by these bacteria are markedly limited or can't even be found. We tried to search in-vitro antimicrobial combinations with synergistic effects for a VIM-2 type MBL producing Pseudomonas aeruginosa, isolated from clinical specimen. On the selection of antibiotic combinations with synergistic effects, we performed a one disk synergy test, modified Pestel's method, in agar without aztreonam (AZT). The bacteriostatic synergistic effects of this tests were scored as $S_1$ (by susceptibility pattern in agar without antibiotics), $S_2$ (by the change of susceptibility in agar with or without antibiotics) and $S_3$ ($S_1$ + $S_2$) and was classified into weak (1 point), moderate (2 points) and strong (3 points) by $S_3$ score. Subsequently, we carried out the time-killing curve for the antibiotic combinations with the strong synergistic bacteriostatic effect. One VIM-2 type MBL producing P. aeruginosa confirmed by the PCR showed all resistance against all ${\beta}$-lactams except AZT, aminoglycoside and ciprofloxacin. In the one disk synergy test, this isolate showed a strong bacteriostatic synergistic effect for the antibiotic combination of AZT and piperacillin-tazobactam (PIP-TZP) or AZT and amikacin (AN). On the time-killing curve after six hours of incubation, the colony forming units (CFUs/mL) of this bacteria in the medium broth with both combination antibiotics were decreased to 1/18.7, 1/17.1 of the least CFUs of each single antibiotics. The triple antibiotic combination therapy including AZT, PIP-TZP and AN was shown to be significantly synergistic after 8 hrs of exposure. In a VIM-2 MBL producing P. aeruginosa with susceptibility for AZT, the triple antibiotic combination therapy including AZT, PIP-TZP and AN may be considered as an alternative antibiotics modality against the infection by some MBL type. But the antimicrobial combination therapy for many more MBL producing isolates is essential to know as soon as possible for the selection of effective treatment against the infection by this bacteria.

• Weed & Turfgrass Science
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• v.4 no.2
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• pp.118-123
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• 2015

Metagenomics is a powerful tool to isolate novel biocatalyst and biomolecules directly from the environmental DNA libraries. Since the metagenomics approach bypasses cultivation of microorganisms, un-cultured microorganisms that are majority of exists can be the richest reservoir for natural products discovery. To discover novel herbicidal substances from soil metagenome, we established three easy, simple and effective high throughput screening methods such as cucumber cotyledon leaf disc assay, microalgae assay and seed germination assay. Employing the methods, we isolated two active single clones (9-G1 and 9-G12) expressing herbicidal activity which whitened leaf discs, inhibited growth of microalgae and inhibited root growth of germinated Arabidopsis seeds. Spraying butanol fraction of the isolated active clones' culture broth led to growth retardation or desiccation of Digitalia sanguinalis (L) Scop. in vivo. These results represent that the screening methods established in this study are useful to screen herbicidal substances from metagenome libraries. Further identifying molecular structure of the herbicidal active substances and analyzing gene clusters encoding synthesis systems for the active substances are in progress.