• Journal of Food Hygiene and Safety
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• v.12 no.1
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• pp.9-14
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• 1997

Vibrio mimicus is a closely related species with V. cholerae, and has been reported to be associated with gastrointestinal infections. Although extraintestinal infections of these vibrios have also been reported in Japan and Southeast Asia. But little research papers on V. mimicus was reported in Korea. Therefore, we tried to isolate V. mimicus from the environmental sea water from April to July in Pusan, Korea. Among the isolated strains, we selected the strongest hemolytic strain and then named V. mimicus SM-9. In this paper, we checked the antibiotic susceptibility and psychrotrophic characteristics of the isolated strain. Hemolytic activity of the hemolysin produced by the isolated strain was also measured. V. mimicus was not detected from the sea water samples in April and May, but its detection rate was relatively high in June and July in Pusan, Korea. The bacteriological characteristics of V. mimicus SM-9 were Gram-negative rods, motile, oxidase positive, Voges-Proskauer negative and sucrose negative. In 23 kinds of antibiotics susceptibility test, V. mimicus SM-9 showed susceptibility to the most of antibiotics submitted while it was resistive against lincomycin, oxacillin, rifampin and vancomycin. Hemolytic activity of the hemolysin produced by V. mimicus SM-9 was highest in stationary phase of the growth curve in BHI broth at 37$^{\circ}C$ and its activity was reached 18 HU per $m\ell$ of culture supernatant. For checking the psychrotrophic property of V. mimicus SM-9, the decreasing rate of the strain in phosphate buffer solution and yellowtail flesh homogenate was examined during the storage at 4, 0, -4 and -2$0^{\circ}C$. The decreasing rates of the selected strain stored in phosphate buffer solution were greater than those in fish homogenate. Decreasing rates of V. mimicus SM-9 stored in phosphate buffer solution were not significantly different by the storage temperatures. The viable cell counts of the strain were decreased as 5 log cycles after 120 hours at all the tested temperatures. While decreasing numbers of the strain in fish homogenates were 2*4 log cycles after 120 hours. The decreasing pattern of the strain numbers were very slow after 200 hours at all the stored temperatures.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.391-398
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• 1989

Triglyceride molecular species In some vegetable oils were analyzed by capillary column gas chromatography and electron impact ionization mass spectrometry utilizing selected ion monitoring. Triglycerides were separated according to their molecular weights and their degrees of unsaturation on $25m{\times}0.25mm$ fused silica open tubular capillary column coated with a phenylmethylsilicone gum stationary phase and in an analysis time less than 13 min. Triglyceride molecular species were identified by analyzing the fragment ions having the same time on the selected ion monitoring profile . The major triglyceride molecular species in each oils were $C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL:18.3%),\;C_{18:2}.\;C_{18:2}.\;C_{18:2}(LLL;\;14.3%),\;C_{18:0}.\;C_{18:2}.\;C_{18:2}(SLL;\;14.1%),\;C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;13.2%),\;C_{16:0}.\;C_{18:2}.\;C_{18:1}(PLO;\;11.6%)$ in corn oil, $C_{18:2}.\;C_{18:2}.\;C_{18:2}(LLL;\;18.0%),\;C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL;\;18.0%),\;C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;17.1%)$ in safflower oil, $C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;23.5%),\;C_{16:0}.\;C_{18:2}.\;C_{18:1}(PLO;\;13.8%),\;C_{18:0}.\;C_{18:1}.\;C_{18:1}(SOO;\;13.5%),\;C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL;\;10.6%)$ in cottonseed oil.

• Korean Journal of Applied Biomechanics
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• v.26 no.1
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• pp.21-30
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• 2016

Objective: This study aimed to examine the characteristics of joint kinematics and synchronicity of rowing motion between elite and non-elite rowers. Methods: Two elite and two non-elite rowers performed rowing strokes (3 trials, 20 strokes in each trial) at three different stroke rates (20, 30, 40 stroke/min) on two stationary rowing ergometers. The rowing motions of the rowers were captured using a 3-dimensional motion analysis system (8-infrared camera VICON system, Oxford, UK). The range of motion (RoM) of the knee, hip, and elbow joints on the sagittal plane, the lead time ($T_{Lead}$) and the drive time $T_{Drive}$) for each joint, and the elapsed time for the knee joint to maintain a fully extended position ($T_{Knee}$) during the stroke were analyzed and compared between elite and non-elite rowers. Synchronicity of the rowing motion within and between groups was examined using coefficients of variation (CV) of the $T_{Drive}$ for each joint. Results: Regardless of the stroke rate, the RoM of all joints were greater for the elite than for non-elite rowers, except for the RoMs of the knee joint at 30 stroke/min and the elbow joint at 40 stroke/min (p < .05). Although the $T_{Lead}$ at all stroke rates were the same between the groups, the $T_{Drive}$ for each joint was shorter for the elite than for the non-elite rowers. During the drive phase, elite rowers kept the fully extended knee joint angle longer than the non-elite rowers (p < .05). The CV values of the TDrive within each group were smaller for the elite compared with non-elite rowers, except for the CV values of the hip at all stroke/min and elbow at 40 stroke/min. Conclusion: The elite, compared with non-elite, rowers seem to be able to perform more powerful and efficient rowing strokes with large RoM and a short $T_{Drive}$ with the same $T_{Lead}$.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.289-293
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• 1998

We investigated the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in methanol extracts of 64 cultured cell lines, which were derived from various plant species, and the ascorbate content in cell lines, which showed a high radical scavenging activity. Thirteen cell lines revealed the antioxidative activity ($IC_{50}$) by methanol extracts of less than 50 mg in cell fresh wt. Of them, six cell lines showed the same Rf value as ascorbate on the DPPH sprayed silica gel TLC. The ascorbate content in cell lines of Rosa multiflora, Scutellaria baicalensis, and Achyranthes japonica showed 48.5, 30.3, and $16.8\;\mu\textrm{g}$ per g cell fresh wt by HPLC analysis, respectively. In callus cultures of S. baicalensis, the concentration of ascorbate reached a maximun ($39{\pm}3.4\;\mu\textrm{g}/g$ cell fresh wt) on 30 days after subculture, which corresponded to the stationary growth phase, and subsequently decreased by successive culturing.

• Journal of Mushroom
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• v.11 no.2
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• pp.53-62
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• 2013

A total of 35 phosphate solubilizing bacterial strains were isolated from waste mushroom bed of Agaricus bisporus in Buyeo-Gun, Chungnam and screened for the production of indole acetic acid (IAA). The best IAA producing strain was identified as Pantoea rodasii using 16S rRNA analysis. In addition to the IAA production, this strain could act as an efficient phosphate solubilizer (1100 ${\mu}g$ $ml^{-1}$ after 5 days of incubation) also. The selected strain was cultured under different conditions in order to assess the optimum conditions for maximum IAA production. The nutrient broth (NB) medium was recorded as the best medium, where the maximum IAA production (229 ${\mu}g$ $ml^{-1}$) was recorded at the start of stationary phase (12 hours after inoculation) of the bacteria growth. The performance of the strain was found to be maximum at the temperature of $30^{\circ}C$ followed by $25^{\circ}C$. IAA production was found to be increased with increasing tryptophan concentration (from 0.1 to 0.6%), however beyond this limit, a slight reduction in IAA production was observed. The strains' ability to produce IAA was further confirmed by extraction of crude IAA and subsequent TLC analysis. A specific spot from the extracted IAA preparation was found corresponding with the standard spot of IAA with same $R_f$ value. The results of HPLC analysis conducted in identifying and quantifying the IAA production more precisely, are in agreement with the results of the assessment done with colorimetric method. As revealed by the results of the pot experiment, the isolated strain could significantly enhance the growth (as measured by shoot and root growth) of mung bean plants compared to that of non-inoculated plants. Therefore it can be concluded that the present strain, Pantoea rodasii has great potential to be used as bio-inoculants.

• Korean Journal of Microbiology
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• v.35 no.2
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• pp.158-163
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• 1999

A ploygalacturonase-produchg yeast was isolated from Cheju soil by selective eivichment media. One strain which has the highesl activity of polygalacturonase was selected. The characle~ishcs of the strain CS-2 were as follows: CS-2 utilized xylose. sucrose, maltose, u.ehalose, cellobiose. melibiose, lactose, raffinose, inosiiol, dulicilol, and dextrose, but did not utilized galactose, nitrate. nit~te, and lysine. Growth of CS-2 was inhibited by cyclohexamide, 1% acetic acid, and high concenaation (over 50%) of glucose. It grew at $30^{\circ}C$ but did 'IIOL $35^{\circ}C$. The cell size ofthe strain CS-2 was 2.9 p ~ n in length and 1.3 $\mu$ in diameter. Vegetable reproductmn was multiple budding and ascospre was present I to 4. Pseudomycelia or true myceliua formation were not observed In any of the cullureq. These results suggest that strain CS-2 is most likely a strain related Cryptococcus spp. (Cryptococcu spp. CS-2). When polygalacturonase or ihe yeast was induced by addition of polygalactoronic acid, polygalacturonase activity was detected in culture supernatent. There was a peak of specific activity a1 he mid-stationary phase(3 days culture) of growth. Polygalacturonase specific activity of Crylmcoccus sp. CS-2 was 2.96 unitsling. The molecular weighl ol'polygalacturonase was showed to be 46 KDa by both SDS-PAGE and activity stailling.

• Korean Journal of Microbiology
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• v.44 no.2
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• pp.85-92
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• 2008

Pseudomonas aeruginosa is an opportunistic human pathogen, causing a wide variety of infections including cystic fibrosis, microbial keratitis, and burn wound infections. The cell-to-cell signaling mechanism known as quorum sensing (QS) plays a key role in these infections and the QS systems of P. aeruginosa have been most intensively studied. While many literatures that introduce the QS systems of P. aeruginosa have mostly focused on two major acyl-homo serine lactone (acyl-HSL) QS signals, N-3-oxododecanoyl homoserine lactone (3OC12) and N-butanoyl homoserine lactone (C4), several new signal molecules have been discovered and suggested for their significant roles in signaling and virulence of P. aeruginosa. One of them is PQS (Pseudomonas quinolone signal; 2-heptyl-3-hydroxy-4-quinolone), which is now considered as a well-characterized major signal meolecule of P. aeruginosa. In addition, recent researches have also suggested some more putative signal molecules of P. aeruginosa, which are diketopiperazines (DKPs) and pyocyanin. DKPs are cyclic dipeptides and structurally diverse depending on what amino acids are involved in composition. Some DKPs from the culture supernatant of P. aeruginosa are suggested as new diffusible signal molecules, based on their ability to activate Vibrio fischeri LuxR biosensors that are previously considered specific for acyl-HSLs. Pyocyanin (1-hydroxy-5-methyl-phenazine), one of phenazine derivatives produced by P. aeruginosa is a characteristic blue-green pigment and redox-active compound. This has been recently suggested as a terminal signaling factor to upregulate some QS-controlled genes during stationary phase under the mediation of a transcription factor, SoxR. Here, details about these newly emerging signaling molecules of P. aeruginosa are discussed.

• Journal of Food Hygiene and Safety
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• v.6 no.3
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• pp.147-155
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• 1991

Enterotoxigenic E. coli is one of the major causative agents of the infantile diarrhea and traveler's diarrhea. The heat-stable enterotoxin(ST) is thought to be a virulence factor in the pathogenesis of the diarrhea and to be a maker for identification of the enterotoxingeic E. coli from non pathogenic E. coli. The isolate of enterotoxigenlc E. coli was isolated from swine during 1989 year(from 5 to 10 month) in the Kyong-gi and Chung-Cheong provinces, and three strains(KM-4, KM-7 and KM-12) was selected from 189 isolates of ST producing E. coli. The detection of a ST produced of the isolated E. coli was performed by the infant mouse assay(IMA). This study was designed to know optimal conditions for the production of the ST and the molecular properties of plasmids of the enterotoxigenic E. coli. Amount of ST produced were the most at initial pH 8.5~9.0 of succinate salts medium culture. The cultural time of the same medium was accumulated the highest level of ST was at the 14 to 16 hours, and then stationary phase was at the 20 hours. From this experiment the KM-7 strain was selected among ST producing strains by IMA. Partial plasmid-curing experiment was done to select plasmid encoding for ST among other plasmids and then comparing the plasmid pattern of ST producing strain(KM-7) with those of other ST non-producing strains, it is found that ST gene exists on the about 80 Kbp plasmid. Each fragment of this plasmid digested with EcoRl was ligated to vector pBR 322 and transformed into E. coli K-12. A clone producing ST(eKT 53) was selected by IMA. The EcoRl digestion pattern of the isolated plasmid(pKD 37) from the ST producing clone it is indicated that the size of the inserted fragment in eKT 53 strain is 16 Kbp. The cultured supernatant of eKT 53 strain was positive result of ST production in IMA.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.272-278
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• 2007

Proteases are enzymes that break peptide bonds between amino acids of other proteins and occupy a crucial position with respect to their applications in both physiological and commercial fields. In order to screen new source of protease, bacteria producing extracellular proteases at low temperature were isolated from deep sea water of East Sea, Korea. A bacterium showing the best growth rate and production of an extracellular protease at low temperature was designated HJ 47. The DNA sequence analysis of the 16S rRNA gene, phenotypic tests and morphology led to the placement of this organism in the genus Pseudoalteromonas. Although maximal growth was observed at $37^{\circ}C$, enzyme production per culture time was maximum at $20^{\circ}C$. At this temperature, extracellluar protease production was detected from the end of the exponential phage to stationary phase, and maximal at 15 hours after initial production. The optimum temperature and pH of the protease were found to be $35^{\circ}C$ and 8.

• KSBB Journal
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• v.24 no.3
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• pp.259-266
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• 2009

AfsR2 in Streptomyces lividans, a 63-amino acid protein with limited sequence homology to Streptomyces sigma factors, has been known for a global regulatory protein stimulating multiple antibiotic biosynthetic pathways. Although the detailed regulatory mechanism of AfsK-AfsR-AfsR2 system has been well characterized, very little information about the AfsR2-dependent down-stream regulatory genes were characterized. Recently, the null mutant of afsS in S. coelicolor (the identical ortholog of afsR2) has been characterized through DNA microarray system, revealing that afsS deletion regulated several genes involved in antibiotic biosynthesis as well as phosphate-starvation. Through comparative DNA microarray analysis of afsR2-overexpressed S. lividans, here we also identify several afsR2-dependent genes involved in phosphate starvation, morphological differentiation, and antibiotic regulation in S. lividans, confirming that the AfsR2 plays an important pleiotrophic regulatory role in Streptomyces species.