• Korean Journal of Microbiology
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• v.37 no.4
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• pp.239-244
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• 2001

We isolated a Myxobacteria strain from a soil sample obtained from Mt. Daedoon located in Choongnam, Korea. This strain, ARJ, secreted slime while swarmed on the surface of CT medium. It produced greenish yellow pigment in liquid or solid media, and the swarming edge showed green florescence under U. V. at 366 nm. It formed fruiting bodies when nutrient was exhausted, which is one of the most imkportant characteristics of Myxobacteria. The fruiting bodies did not have a stalk and consisted of naked myxospores when examined under the scanning electron microscope. These traits lead us to believe that this strain is very close to Myxococcus virescens. It showed antimicrobial activity, especially against Gram positive bacteria. Culture filtrate showed the activity but this was not due to protein. The culture filtrate also had proteolytic activity in which at least two enzymes are involved.

• Journal of Bio-Environment Control
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• v.12 no.3
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• pp.160-165
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• 2003

This study was carried out to investigate the effect of several substrates; used rockwool, several spent mushroom composts, and common used media, such as rockwool and vermiculite, on growth and fruit quality of cucumber. Cucumber grew dramatically in the rockwool+peatmoss (1:2 v/v) (RP) and fine granular rockwool in hydroponic system using Yamaztiki's solution for cucumbers. The yield of cucumber fruit was highest in recycled winter mushroom compost (RW), and followed by 100% perlite (Par), recycled oyster mushroom compost (RO), and RR but there was no significant difference among these three media. Soluble solid and firmness were higher in Per and vermiculite (Ver), and any difference was not found among the others. Vitamin C was not influenced by kind of substrate. The results confirm that several reused or recycled substrates have high possibilities for use as medium for hydroponic culture in cucumber.

• 한국균학회소식:학술대회논문집
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• 2018.05a
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• pp.29-29
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• 2018

Sparassis latifolia is called "Cauliflower Mushroom" and is known as an edible mushroom that has high content of ${\beta}$-glucan. Recently, artificial cultivation of S. latifolia has been done by bottle, plastic bag and wood cultivation in Korea. However it is not widely used because there are low incubation ratio and yield. For the high efficiency of production, we aim to find the superior strains and media for better mycelial and fruit body growth. First, we analyzed the genetic relationship among 31 strains and divided five groups with three kinds of URP primers. And then ten strains were selected from five groups based on the experiment of mycelial growth. The suitability of media for mycelial growth was different according to media type. The suitable solid and liquid media for mycelial growth of S. latifolia isolates were PDA and M2, respectively. In addition, with regard to C/N ratio, the mycelial growth increased even until C/N 160. Second, we investigated the production of fruitbody of the strains by plastic bag cultivation. The substrate was mixed with larch sawdust, corn flour, and wheat flour (8:1:1, v/v). Moisture content of substrate was controlled by about 60% with 10% molasses solution. Out of 31 strains, 19 strains formed primordia. The eight strains produced more than 140g/1kg in fresh weight. Third, molasses culture media was selected for the mycelial growth. And molasses suitable sugar content and input aeration were around 8Brix% and 0.3~0.6vvm, respectively. The longer the incubation period is, the more dried weight of mycelia increased, but medium volume decreased. Therefore, the best incubation period was 9 to 11 days depending on strains. In the future, research project entitled development of culture system and new variety for stable production of S. latifolia will be considered as a new item.

• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.542-546
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• 2009

Recently, silver has been applied to various fields due to antimicrobial property and high conductivity. We manufactured high-performance ophthalmic material containing silver which could protect eye from environmental factors. We mixed $AgNO_3$ with conventional contact lens material. And then we copolymerized at 70 ${^{\circ}C}$ for 40 minutes under water bath, and estimated antimicrobial activity and physical properties. We used solid culture and liquid culture medium for antimicrobial test. The results of contact lens containing silver showed good antibiosis. In case of physical properties, the results showed 32.35%(water content) and 88.34% (visible transmittance) for each. We judged that we made the copolymer with antimicrobial and physical properties which is suitable for conventional contact lens.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.4
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• pp.82-90
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• 2001

This study was carried out to reveal optimum conditions for in vitro propagation of 3 Korean native azalea species, Rhododendron mucronulatum, R. yedonese var. poukhanense, and R. shlippenbachii, which are useful for landscape proposes. Seeds and meristems from three azalea species were cultured on 1/2MS, Hyponex, and Anderson media containing growth of regulators benzyladenine(BA) and 2-isopentenyadenosine(2ip). The results were as follows. 1. In the culture of R. schlippenbachii and R. mucronulatum seeds, in vitro seedlings germinated and grew well on he 1/2MS and Anderson media, while R. yedoense var. poukhanense on Hyponex media containing 6.0mg/$\ell$ 2ip. 2. When the meristems of R. mucronulatum were cultured on Andeson media containing 9.0mg/$\ell$ 2ip, the survival rate of meristems was 23.0% in 6 weeks after culture, and the survival rate of R. schlippenbachii was 46.0% o nthe same media containing 12.0mg/$\ell$ 2ip. The survial rate of R. yedoense var. poukhanense was 92.0% onHyponex media containing 0.5mg/$\ell$ BA and 9.0mg/$\ell$ 2ip. When the meristems of R. mucronulatum and R. yedoense var. poukhanense were cultured on Hyponex media containing 12.0mg/$\ell$ 2ip, they showed the most excellent growth. R. schlippenbachii grew well on Anderson media containing 9.0mg/$\ell$ 2ip. When in vitro shoots of R. yedoense var. poukhanense were subcultured to solid medium, they grew well in shoot growth on Hyponex media containing 6.0mg/$\ell$ 2ip.

• Microbiology and Biotechnology Letters
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• v.3 no.3
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• pp.147-156
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• 1975

The possibility of using tapioca pellets as a raw material in glutanmic acid fermentation by Microcuccus glutamicus is shown. The ground pellets were diluted with water to 20％ solid level and treated with $\alpha$-anylase prepared from a thermophilic Actinomycetes strain culture for 90 min at 85$^{\circ}C$ under pH 6.0. The liquefied solution was further saccharified with commercial glucoamylase for 36 hours under the reaction conditions of 55$^{\circ}C$ and pH 5.0. The inhibitory effect of excess biotin content, 16 $\mu\textrm{g}$ Per liter of the hydrolzate, could be reduced effectively by adding 10 IU of penicillin per ml of the medium after five hours of the fermentation. The maximum glutamic acid yield of 38.5 g/l was obtained after 60 hours of shaking culture at 28-3$0^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.34 no.5
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• pp.1135-1145
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• 2024

When cells are exposed to freezing temperatures, high concentrations of cryoprotective agents (CPA) prevent ice crystal formation, thus enhancing cell survival. However, high concentrations of CPAs can also cause cell toxicity. Exopolysaccharides (EPSs) from polar marine environments exhibit lower toxicity and display effects similar to traditional CPA. In this study, we sought to address these issues by i) selecting strains that produce EPS with novel cryoprotective activity, and ii) optimizing culture conditions for EPS production. Sixty-six bacteria producing mucous substances were isolated from the Ross Sea (Antarctic Ocean) using solid marine agar plates. Among them, Pseudoalteromonas sp. RosPo-2 was ultimately selected based on the rheological properties of the produced EPS (p-CY02). Cryoprotective activity experiments demonstrated that p-CY02 exhibited significantly cryoprotective activity at a concentration of 0.8% (w/v) on mammalian cells (HaCaT). This activity was further improved when combined with various concentrations of dimethyl sulfoxide (DMSO) compared to using DMSO alone. Moreover, the survival rate of HaCaT cells treated with 5% (v/v) DMSO and 0.8% (w/v) p-CY02 was measured at 87.9 ± 2.8% after freezing treatment. This suggests that p-CY02 may be developed as a more effective, less toxic, and novel non-permeating CPA. To enhance the production of EPS with cryoprotective activity, Response Surface Methodology (RSM) was implemented, resulting in a 1.64-fold increase in production of EPS with cryoprotective activity.

• Tuberculosis and Respiratory Diseases
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• v.65 no.5
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• pp.379-384
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• 2008

Background: Sputum decontamination with NALC-NaOH (N-acetyl-L-cysteine-sodium hydroxide) is known to better detect Mycobacterium tuberculosis (M. tb) by culture than that with using NaOH, which is widely used in Korean hospitals. In this report, sputum samples collected from pulmonary tuberculosis (TB) patients were treated with either NaOH or NALC-NaOH, and we compared the results of smear and culture positivity to determine whether the NALC-NaOH treatment method improves culture positivity in the sputum samples, and especially for those sputum samples that are smear negative and scanty. Methods: For each decontamination method, 436 sputum samples from pulmonary TB patients in the National Masan Tuberculosis Hospital were collected for this study. Sputum from a patient was collected two times for the first and second day of sampling time, and these samples were employed for the decontamination process by performing the 4% NaOH and NALC-2% NaOH treatment methods, respectively, for detecting M. tb by an AFB (Acid Fast Bacilli) smear and also by culture in solid Ogawa medium. Results: The NaOH and NALC-NaOH treatment methods did not significantly affect the AFB smear positivity of the sputum samples (33.0% vs 39.0%, respectively, p=0.078). However, the culture positive percents of M. tb in the Ogawa medium treated with NALC-NaOH and NaOH were 39.7% and 28.0%, respectively, which was a significantly different (p=0.0003). This difference in culture was more prominent in the sputum samples that were smear negative (the positive percents with NALC-NaOH and NaOH were 15.8% and 7.2%, respectively, p=0.0017) and scanty (NALC-NaOH and NaOH were 60.8% and 42.9%, respectively, p=0.036), but not for a smear that was 1+ or higher (p>0.05). Conclusion: NALC-NaOH treatment is better than NaOH treatment for the detection of M. tb by culture, but not by smear, and especially when the AFB smear is negative and scanty.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.1
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• pp.72-84
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• 1993

This study was carried out to understand the varietal variation in physicochemical properties of rice grain and those environmental changes by different transplanting time, and to elucidate the interrelationships among the factors related with eating quality of cooked rice. Fifty three rice samples, among which fifty samples were harvested at ordinary or late transplanted plots of the Crop Experiment Station in Suwon and three samples were harvested orpurchased from Niigata prefecture in Japan, were tested for various physicochemical components of rice grain and some physical factors of cooked rice. All of twenty seven rice cultivars tested were the recent-bred Korean japonica rice showing the wide range of maturity from early to medium-late heading and considerable difference in palatability of cooked rice. Amylose content, taste value by Nireco palatability tester (TVN), iodine blue color of cooking extracts(IB), and the ratio of IB /extracted solid amounts (ES) increased significantly by late transplanting, while viscosity (VN) and Mg / K. N value by Nireco tester, hot-water absorption of milled rice (HA), loss tangent of cooked rice by Rheolograph-Micro(LT), and most viscogram characteristics except setback viscosity (C-P) decreased drastically by late transplanting as compared with ordinary transplanting. Most of physicochemical properties of milled rice revealed narrower varietal variation in lately transplanted plot than in ordinary transplanted one. Protein content (PRO), volume expansion rate of cooked rice(VE), C-P and all physical factors of cooked rice by Rheolograph-Micro showed almost negligible seasonal variation, while amylose content (AM), VN, HA, IB/ES, peak viscosity(P), hot viscosity(H) and breakdown(P-H) viscosity exhibited considerably large seasonal variation. The early-headed varieties revealed lower amylose content and smaller seasonal variation of IB/ES compared with medium or medium-late headed rice varieties. AM was closely associatied with IB and IB / ES and VN was highly correlated with Mg/K. N and TVN in both ordinary and late transplanted plots. VN also was highly negatively correlated with cooking characteristics and highly positively correlated with viscogram properties in ordinary culture. PRO was closely connected with moisture content of milled rice and L T in ordinary transplanted plot. IB, which was closely connected with ES, was also singificantly associated LT, P and P-H in ordinary seasonal culture. IB/ES was highly negatively correlated with P, P-Hand P-H / C-P in ordinary culture but with LT and dynamic viscosity of cooked rice in late seasonal culture. The thirty rice cultivars were largely classified into two varietal groups by cluster analysis with physicochemical properties related with eating quality of cooked rice. Korean and Japanese high-quality rice cultivars were separately distributed in two respective varietal group.

• 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.