• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.345-352
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• 1998

The diagnosis of brucellosis is currently based on serological and microbiological tests. However, the microbiological isolation and identification have several disadvantages such as time-consuming and laborious, and the serological methods have been reported to cross-react with antigens other than those from Brucella spp. To develop a sensitive and rapid diagnostic method for detection of Brucella species, the genus-specific primers were designed and synthesized from the sequence of gene encoding a 31kDa cell surface protein(BCSP) and a 36kDa outer membrane protein(OMPB) of B abortus. The amplified 711bp and 982bp DNA fragments were only visible in each species of Brucella by PCR method using the BCSP and OMPB primers, respectively. However, PCR product was not obtained with DNA from other Gram-negative bacteria. As little as 1pg of the B abortus genomic DNA could be detected by this PCR method. Using the PCR technique, semen samples from 185 bulls of Brucella-seronegative herds in Cheju island were examined for comparison of this PCR method with conventional methods in 1995. The semen samples from 5 bulls were positive by culture method and PCR, and one was positive and 5 were suspect by semen plasma agglutination test. However, the semen samples obtained from 177 bulls were negative by semen plasma agglutination, culture and PCR methods in 1996. The results of comparison tests suggested that PCR was a better test than agglutination test against semen of bulls. This study indicated that the PCR technique was a valuable for the diagnosis of bovine brucellosis, particulary in bull semens.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.246-255
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• 1996

To develop a natural antioxidative peptide, the gelatin was extracted from fish (Yellowfin sole) skin by hot $water(50^{\circ}C)$ extraction method and hydrolyzed with Alcalase, pronase and collagenase through a continuous 3-step membrane reactor. Each step enzymatic hydrolysates were determined the antioxidative activity and their synergistic effects, compared with $\alpha-tocopherol$ and butylated hydroxytoluene (BHT). Also, we tried to investigate the antioxidative disposition of peptide which was successfully separated by gel filtration, ion-exchange chromatography, and HPIC in cultured rat hepatocytes intoxicated with tert-butyl hydroperoxide (TBHP). Second step enzymatic hydrolysate (SSEH) among all hydrolysates and $\alpha-tocoperol$ was showed the strongest antioxidative activity. The optimum concentration of antioxidative activity for SSEH was $1\%(w/w)$ in linoleic acid. The synergistic effects were increased in using the hydrolysate with tocopherol and BHT. In the presence of the peptide isolated from SSEH, supplemented hepatocytes exposed to TBHP showed that delayed cell killing and decreased significantly the lipid peroxidation, compared with hepatocytes not cultured with isolated peptide.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.451-455
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• 2006

An efficient pilot scale (10 ton) three-stage methane fermentation system to digest food waste has been developed in this laboratory. This system consisted of three stages: semianaerobic hydrolysis, anaerobic acidogenesis and strictly anaerobic methanogenesis. From the secondary acidogenesis reactor, a novel strain KA4 responsible for alcohol fermentation was isolated and characterized. The cell was oval and its dimension was $5.5-6.5{\times}3.5-4.5\;{\mu}m$. This strain was identified as Saccharomyces cerevisiae KA4 by 26S rDNA D1/D2 rDNA sequence. Optimal culture temperature was $30-35^{\circ}C$. Cells were tolerant to 5% (v/v) ethanol concentration, however, were inhibited significantly by higher ethanol concentration up to 7%. The strain could grow well up to 50% (w/v) initial glucose concentration in the YM liquid medium, however, optimal concentration for ethanol fermentation was 10%. It could produce ethanol in a broad initial pH range from 4 to 10, and optimal pH was 6. In this condition, the strain converted 10% glucose to 7.4% ethanol during 24 hr, and ethanol yield was estimated to be 2.87 moi EtOH/mol glucose.

• Environmental Mutagens and Carcinogens
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• v.26 no.2
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• pp.53-58
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• 2006

Normally, environmental toxicants are classified as endocrine disruptors if they interfere with regulation of cellular function by endogeneous steroids through inhibition of receptor binding and/or transcriptional activation. So, many studies have been performed about agonist/antagonist of hormone receptor to study mechanisms of endocrine disruptors. If toxicants affect steroid biosynthesis and/or degradation and alter hormone homeostasis, these also are classified as endocrine disruptors. But there are not many studies of the mechanisms of endocrine disruptors on the basis of alteration of steroid biosynthesis and/or degradation. Isolation and culture of Leydig cells from testis is one of methods for the steroidogenesis screening assays to evaluate a substance for altering steroidogenesis. Leydig cells were harvested using the method described by Klinefelter with modifications. Leydig cells were purified by perfusion of testis and incubation ($34^{\circ}C$, 80cycles/minute, 20 minutes) with collagenase (0.25 mg/kg), centrifugal elutriation, percoll gradient centrifugation and BSA multidensity gradient centrifugation. To confirm if this method is one of appropriate tools to evaluate a substance for altering steroidogenesis, ketoconazole, positive control was administered to purified Leydig cells. Ketoconazole ($10^{-8}M$ and above) significantly reduced testosterone production in purified Leydig cells. From above results, we suggest that this method for steroidogenesis screening assay appears to be a appropriate tool to detect suspected compounds for altering steroidogenesis.

• Journal of Mushroom
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• v.13 no.3
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• pp.270-273
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• 2015

Hypsizigus marmoreus is commercially the most important edible mushroom in Japan. This mushroom is usually cultivated for a longer period (about 85~120 days) than other mushroom. In order to develop a new cultivar that has a shortened cultivation period, the genome analysis of this strain has been considered. This study aims to obtain parental monokaryotic strains reproducing 'Haemi' cultivar in Hypsizigus marmoreus for reference genome sequencing. The mycelia were cultured in MCM and MYG media for various incubation periods. Homogenized mycelia were treated with commercial cell wall degrading enzymes to maximize protoplasts production yield from Hypsizigus marmoreus. The greatest number of protoplasts was obtained from mycelia cultured in MCM media for 3 days using Novozyme enzyme. The isolated protoplasts were grown in regeneration agar media after two weeks. Regenerated colonies were picked and moved on separated dishes for microscopic observation. Neohaplonts regenerated from dikayotic strains were identified by the absence of clamp connections. We confirmed that one of monokaryotic strains is a parental strain by crossing with an original compatible strain of 'Haemi' cultivar. This parental strain will be used for reference genome sequence analysis.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.780-786
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• 1993

About 7.7% of the total anaerobic bacteria in pig feces grew with clear zone around the colonies on the agar medium containing inulin as a sole carbon source. Among these bacteria, a strain with the strongest inulin-utilizing activity was isolated and identified as Bacteroides sp. based on its morphological and taxonomical characteristics. The isolate grew well with inulin, fructooligosaccharides or glucose as a sole carbon source, while its growth dropped to 50% of that obtained with glucose when soluble starch or sucrose are used. Since the inulase activity was found only when fructooligosaccharides or inulin was added to the growth medium, but not when glucose, sucrose or soluble starch was applied, the inulase production was considered to be induced by fructooligosaccharides or inulin. The highest inulase activity, 0.42 U/ml was detected with the inulin medium and 0.25 U/ml with fructooligosaccharides medium. The cell growth of the isolated strain increased with the amounts of inulin up to 2%(w/v) and maximum production of inulase was found in the cells fed 1% inulin. The inulase of the isolated Bacteroides sp. showed its maximum activity at pH $7.0{\sim}7.5\;and\;50{\sim}50^{\circ}C$ and was found to be an exoinulase judging by its mode of action.

• Journal of Ginseng Research
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• v.32 no.4
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• pp.300-304
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• 2008

Cysteine proteinases play an essential role in plant growth and development but also in senescence and programmed cell death. They participate in both anabolic and catabolic processes. In addition, they are involved in signalling pathways and in the response to biotic and abiotic stresses. A cDNA clone encoding cysteine proteinase (CP) gene, designated PgCysP1, was isolated from Panax ginseng C. A. Meyer. Reverse transcriptase (RT)-PCR results showed that PgCysP1 expressed at different level in P. ginseng hairy root. Different stresses such as biotic as well as abiotic stresses triggered a significant induction of PgCysP1. The positive responses of PgCysP1 to the various stimuli suggested that PgCysP1 may help to protect the plant against reactive environmental stresses.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.194-202
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• 2003

To isolate alga-lytic bacteria, a number of samples were collected from Lake of Sukchon and Pal'tang reservoir where cyanobacteria blooming occurred. HY0210-AK1, which exhibited high alga-lytic activity, was isolated using Anabaena cylindrica lawn. The morphological and biochemical characteristics of the isolate HY0210-AK1 were very similar to that of the genus Rhizobium. Taxonomic identification including 16S rDNA base sequencing and phylogenetic analysis indicated that the isolate Hy0210-AK1 had a 99.1% homology in its 16S rDNA babe sequence with Sphingobium herbicidovorans. A. cylindrica NIES-19 was susceptible to the alga-lytic bacterial attack. The growth-inhibiting offset of the bacterium was not different on A. cylindrica NIES-19 when Sphingobium herbicidovorans HY0210-AK1 was in the lag, exponential, and stationary growth phase, although the alga-Iytic effect of S. herbici-dovorans HY0210-AK1 that in stationary growth phase was somewhat pronounced at the first time of inoculation. When S. herbicidovorans HY0210-AK1 was inoculated was inoculated with $1\times 10^{8}$ CFU $ml^{-1}$ together with A cylindrica NIES-19, the bacterium proliferated and caused algal lysis. A. cylindrica NIES-19 died when S. herbicidovorans HY0210 AKl was added to the algal culture but not when duly the filtrates from the bacterial culture was added. This suggests that extracellular substances are not responsible for inhibition of A. cylindrica NIES-19 and that algal Iysis largely attributed to direct interaction between S. herbicidovorans HY0210-AK1 and A. cylindrica NIES-19. The alga-lytic bacterium HY0210-AK1 caused cell lysis and death of three strain of Micro-cystis aeruginosa, but revealed no alga-Iytic effects on the Stephanodiscus hantzschii.

• Parasites, Hosts and Diseases
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• v.29 no.2
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• pp.149-160
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• 1991

Each of SPF mice(Scl: ICR strain, 3-week-old males) was inoculated with 5$\times$104 oocysts of Cryptosporidium by stomach tube. The oocysts were large type one which was previously isolated from Korean mice, and passaged in 3-week-old SPF mice. The patterns of oocyst discharge were monitored daily, and in order to observe the ultrastructure of developmental stages the stomach of the mice was examined by transmission electron microscopy (TEM) at 4 weeks post-inoculation. The prepatent period for 6 mice was 5.6 days post-inoculation on the average, and the patent period was 63.2 days. The number of oocysts discharged per day from the mice reached peak on day 36.6 post-inoculation on the average. A large number of oocysts were found in fecal samples obtained from inoculated mice on days 30~50 post-inoculation. C. tsuris was larger than C. parvum at almost every developmental stages, the sixte difference being 1.4 times in oocysts, 2.4 times in sporozoites, 1.6 times in merozoites, and 1.5 times in microgametes. The ultrastructural features of the attachment site of C. tsuris to the mucus cells were remarkably different from those of C. parvum and its closely related species. The anterior projection of the protozoa (C. muris), the outer aspect of which was surrounded by a thick filamentous process of the host cell, has not been reported at any developmental stages of C. parvum or its closely related species. The size of the oocysts of strain RN 66 was larger than that of Korean mice origin. The above results reveal that the large type Cryptosporidium of Korean mice origin is identified as Cryptosporidium muris and this type was named as C. muris (strain MCR).

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1798-1807
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• 2002

This study was conducted to investigate lactobacillus salivarius subsp. salivarius having probiotic properties to be used as the health adjuncts with fermented milk products. Acid- and bile-tolerant lactobacillus salivarius subsp. salivarius was isolated with lactobacilli MRS broth from faeces of 80 healthy persons (infants, children and adults). It was used as a probiotic strain in fermented milk products. The pH of fermented milk decreased from pH 6.7 to 5.0 and titratable acidity increased from 0.3% to 1.0% by L. salivarius subsp. salivarius (isolation strain 20, 35, and 37), when incubated for 36 h at 37$^{\circ}C$. The number of viable cell counts of fermented milk was maximized at this incubation condition. The SDS-PAGE evidenced no significant change of casein but distinct changes of whey protein were observed by isolated L. salivarius subsp. salivarius for titratable acidity being incubated by 0.9-1.0% at 37$^{\circ}C$. All of the strains produced 83.43 to 131.96 mM of lactic acid and 5.39 to 26.85 mM of isobutyric acid in fermented products. The in vitro culture experiment was performed to evaluate ability to reduce cholesterol levels and antimicrobial activity in the growth medium. The selected L. salivarius subsp. salivarius reduced 23-38% of cholesterol content in lactobacilli MRS broth during bacterial growth for 24 h at 37$^{\circ}C$. All of the isolated L. salivarius subsp. salivarius had an excellent antibacterial activity with 15-25 mm of inhibition zone to E. coli KCTC1039, S. enteritidis KCCM3313, S. typhimurium M-15, and S. typhimurium KCCM40253 when its pH had not been adjusted. Also, all of the isolated L. salivarius subsp. salivarius had partial inhibition zone to E. coli KCTC1039, E. coli KCTC0115 and S. enteritidis KCCM3313 when it had been adjusted to pH 5.7. The selected strains were determined to have resistances of twelve antibiotic. Strains 27 and 35 among the L. salivarius subsp. salivarius showed the highest resistance to the antibiotics. These results indicated that some of the L. salivarius subsp. salivarius (strain 27 and 35) are considered as effective probiotic strains with a potential for industrial applications, but the further study is needed to establish their use as probiotics in vivo.