• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.347-351
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• 1998

Plant regeneration via organogenesis from leaf and stipule explants of micropropagated shoots of strawberry (Fragaria $\times$ ananassa cv. Suhong) was achieved. Leaf and stipule explants were detached from shoot-tip cultured shoots and cultured on MS medium with various combinations of BA and NAA under light or dark condition. Shoot regeneration from leaf explant was observed after 3 weeks in culture and was good at the high ratio of BA and NAA among various combination treatments. The highest shoot regeneration frequency from leaf explants was obtained with 1.0 mg/L BA and 0.1 mg/L NAA, in which 31.1% shoot regeneration frequency(1.7 shoots per leaf explant) was yielded. In case of stipule explants, shoot regeneration was largely affected by plant growth regulators during incubation under dark condition for initial 4 weeks but not under continuous light condition. The combination treatment with 2.0 mg/L BA and 0.1 mg/L NAA showed the most excellent shoot regeneration from stipule explants, where 44.4% regeneration frequency(4.0 shoots per explants) obtained. Regenerated shoots were rooted on MS medium with 0.1 mg/L NAA after shoot elongation, and the plantlets regenerated were transferred to soil mixtures with vermiculite and perlite for acclimation.

• Journal of Food Hygiene and Safety
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• v.5 no.1
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• pp.27-34
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• 1990

As a link in the studies on the extracellular polysaccharide by lactic acid bacteria, the experiment was conducted to investigate the viscosity variations of 10% reconstituted skim milk and optimum cultural conditions for the production of extracellular polysaccharide. 1. The viscosity of 10% reconstituted skim milk cultured by 8tr. thermophilu8 510 reached 5,000 CP at $41^{\circ}C$ and on 5 days. Because it was the highest value among the microorganisms tested, Str. thermophilu8 510 was chosen as a main test microoganism and studied on factors affecting maximum viscosity depending upon production of exopolysaccharide. 2. Absorbance of synthetic culture medium was highest at $41^{\circ}C$. Sucrose, in a member of carbohydrates, was the most effective carbon source for the production of exopolysaccharide within 5% concentration. 3. The production of exopplysaccharide was stimulated by $Mg^{++}$.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.470-474
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• 2003

DNA sequence information on small-subunit rRNA gene (16S rDNA) obtained from food-poisoning bacterial culture was used to investigate the presence of bacterial pathogens in food. By reverse dot blot detection method, presence of food-poisoning bacteria could be confirmed on hybridization of digoxigenin-labeled 16S rDNA Polymerase Chain Reaction (PCR) primer product and biotin-labeled specific oligonucleotide probe. Escherichia coli, Bacillus cereus. and Salmonella sp. were used as the representative food-poisoning bacterial microorganisms. An oligonucleotide probe, based on the variable region of 16S rRNA gene, was used as the specific probe. These tools may be more useful than classic biochemical method for rapid identification of contaminated food.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.430-434
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• 1997

Axillary bud explants from 3-year-old seedlings of Forsythia saxatilis N., rare and endangered species in Korea, were cultured on Murashige and Skoog's medium. The effect of various cytokinins(BAP, kinetin, and zeatin) at the different concentration(0.2, 0.5 and 1.0mg/L) was tested. Although an apparent shoot proliferation was not observed, zeatin showed slight promotional effect on normal shoot and leaf development. Both shoots and adventive roots could be induced simultaneously when the explants were cultured on the medium with kinetin, but adventive rooting was gradually reduced according as BAP and zeatin concentrations increased. Axillary shoot growth was promoted by the etiolation treatment. Shoot proliferation has been maintained more than three years with consecutive subculture. Rooted plantlets were successfully acclimatized in the artificial soil mixture and showed normal growth after transplantation into field.

• Journal of Mushroom
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• v.3 no.1
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• pp.40-44
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• 2005

The results of examining selection of optimal mycelial growth condition excellent strain for determining the condition of Pleurotus cornucopiae are as follows. 1) Mycelial growth and density of P. cornucopiae were the highest in the medium of MCM(87.8mm/10d) followed by the order of PDA, YM, MEA and Czapek. 2) Optimal temperature for the mycelial growth and density of P. cornucopiae was shown to be $25^{\circ}C$, but the hyphae were dead at $5^{\circ}C$. The mycelial growth and density of KNAC2003 strain was the highest at $25^{\circ}C$(87.8mm/10d) followed by the order of 25, 30, 20, 35, 10 and $5^{\circ}C$. 3) Optimal pH for the mycelial growth and density was revealed to be 6.0(88.3mm/10d), but the mycelial growth and density were shown to be retarded in above or below pH 6.0.

• Journal of Life Science
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• v.9 no.3
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• pp.268-275
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• 1999

Rhodopseudomonas sp. was immobilized in three supports(agar, k-carrageenan, and PVA) in order to remove nitrate in wastewater coming from fish farm. Among them 3% agar was the most suitable support when denitrification rate and bead durability were tested. Optimum bead size was 4mm-diameter when the substrate transfer into the bead and shear stress for bead were considered, and optimum cell loading was 25mg dry $cells/cm^2$gel gel. Ethanol was the best as a carbon source, and optimum C:N ratio, temperature and pH were 1.5:1, $31^{\circ}C$,, and 6, respectively. Under these conditions the maximum denitrification rate in synthetic wastewater was $$345{\MU}{\ell};N_2/Cm^3 gel{\cdot}hr;and that in modified MYC medium was 450{\MU}{\ell}};N_2/Cm^3 gel{\cdot}hr $$.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.6
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• pp.75-83
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• 2004

Focusing on native plants that have high possibility of being introduced as rooftop material, this study was conducted to investigate extensive and easy-to-manage rooftop garden and to raise the utilization of native plants by verifying their growing response to artificial substrate soil depth and irrigation period. The study was conducted from March to September in 2002. Plants tested included Chrysanthemum zawadskii, Sedium middendorffianum, Thymus quinquecostatus, Allium senescens, and Dianthus superbus. Regarding soil depth, it was 5 cm and 10 cm. Irrigation period was non-irrigation, 1-week, 2-weeks, and 3- weeks, Its result is as follows; 1. In case of Sedum middendorffianum Maxim, mortality rate was 0% regardless of soil depth and irrigation period making it very suitable material for rooftop garden. 2. In case of Allium senescens L., mortality rate was 0% regardless of soil depth and irrigation period making it very suitable material for rooftop garden. Therefore, Provided that fertilizing is managed well, it is a plant that can be highly utilized.3. In case of Chrysanthemum zawadskii Herb. Subsp. (Nakai) Y. Lee Stat., the growth of top was lower in 10cm than in 5cm and it grew well in 10cm. When utilizing for rooftop garden, it would be desirable to keep minimum viable soil depth at over 10cm. If there is enough rainfall, soil and soil depth seem to have greater effect on growth than irrigation period does. 4. In case of Diauthus superbus L. var. longicalycinus (Maxim) Williams, rooting rate and growth were better in 10cm than in 5cm. Therefore, it is desirable to keep minimum soil depth at over 10cm. 5. In case of Thymus quinquecostatus Celak, the growth of top and flowering were better in 10cm than in 5cm. Therefore, it seems desirable to have minimum viable soil depth to be over 10cm. In conclusion, the most suitable species for rooftop garden are Sedium middendorffianum and Allium senescens in this experiment. However, Chrysanthemum zwadskii, Thymus quinquecostatus, and Dianthus chinensis also can be utilized greatly when irrigation is managed regularly in artificial mixed soil over 10cm.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.180-189
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• 2004

Chlorhexidine dihydrochloride and sodium fluoride have been used as agents inhibiting the replication of oral bacteria and the formation of dental plaque. There are various kinds of bacteria with different sensitivity against these agents. In this study, chlorhexidine dihydrochloride and sodium fluoride were studied about their effects on the replication of Streptococcus mutars, Streptococcus sobrinus, Streptococcus oralis and Streptococcus salivarius at their concentrations inhibiting the formation of artificial plaque by Streptococcus mutars. When Streptococcus mutans was cultured for 8 hours in the media added with $1.0{\mu}M$ chlorhexidine dihydrochloride, the weight of formed artificial plaque was decreased to $5.1{\pm}1.5mg$ compared with $106.1{\pm}18.1mg$ of the control(p<0.05). At the same time, the optical density of cultured media was decreased. The optical density of cultured media was slightly decreased in Streptococcus sobrinus, but was not decreased in Streptococcus oralis. The optical density of Streptococcus salivarius was decreased at 8 hours-incubation, was not decreased at 24 hours-incubation. When Streptococcus mutars was cultured for 8 hours in the media added with 3.0 mM sodium fluoride, the weight of formed artificial plaque was decreased to $26.7{\pm}8.3mg(p<0.05)$. At the same time, the optical density of cultured media was decreased. The optical density of cultured media was decreased in Streptococcus sobrinus and Streptococcus oralis, but was slightly decreased in Streptococcus salivarius. These results suggest that at the concentration of chlorhexidine dihydrochloride and sodium fluoridehe inhibiting the formation of artificial plaque by Streptococcus mutans, different species of genus Streptococcus show the different sensitivity against these agents.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.281-294
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• 2018

Molecular analysis using the internal transcribed spacer region sequences revealed that the strains used in this study, which were formerly identified as Panellus serotinus, are Panellus edullis. After Universal Fungal PCR Fingerprinting (UFPF) analysis, eight strains of P. edulis were divided into two groups. We conducted fundamental research on mycelial growth and sawdust cultivation to understand the cultural characteristics of eight wild P. edulis strains collected from Korean forests. All strains showed faster and denser mycelial growth on potato dextrose agar (PDA) than on other media (malt extract agar, Sabouraud dextrose agar). Optimal conditions for mycelial growth were: $20^{\circ}C$ on PDA, $25^{\circ}C$ on potato dextrose broth (PDB), and pH 5~8 on PDB at $25^{\circ}C$. Two strains (NIFoS 2407, 3993) were selected as excellent strains based on mycelial growth and density on PDA. NIFoS 2792 showed high cellulase activities on carboxymethyl cellulose (CMC) agar, and NIFoS 2387 and 2804 exhibited high laccase activities on ABTS-containing agar media. The mycelial growth of P. edulis was the fastest on Quercus acutissima and Q. mongolica sawdust media, and mycelial density was the highest on Quercus spp. sawdust-containing media. Sawdust cultivation of P. edulis was successful. The conditions were 80~85 days of cultivation period after spawn inoculation, 10~11 days for primordial formation at $17{\sim}18^{\circ}C$, and 15~20 days for fruiting growth. NIFoS 2804 and 3993 were selected as good strains in terms of cultivation period and mushroom production. These results could be useful for the artificial cultivation of P. edulis.

• Journal of Mushroom
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• v.2 no.3
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• pp.149-156
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• 2004

This study was carried out to obtain basic data on physiological characteristics for an artificial cultivation of fruiting body of Cordyceps. Specimens such as Cordyceps longissima, C. militaris and C. pruinosa were collected at Mt. Halla of Cheju island in July, 2003. Among four different culture media which have been used for culture of mushrooms, MCM medium was selected for the favorable culture medium of the Cordyceps tested. The initial pH of solid medium for mycelial growth of Cordyceps was good in the range of pH 5.0~7.0 lower than 8.0. The mycelial growth of C. longissima was most favorable on culture media supplemented with glucose, one of monosaccharides. In C. militaris, nine carbon sources were favorable to the mycelial growth as compared with control among 11 carbon sources. Six nitrogen sources were favorable to the mycelial growth of C. longissima as compared with control among 9 carbon sources; namely, the mycelial growth of C. longissima was most favorable on culture media contained potassium nitrate, and followed in order by ammonium citrate and sodium nitrate in 4 weeks incubation.