• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.4
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• pp.217-224
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• 2001

In order to identify the growth characterization, the yield and chemical composition of Jeju barnyard grass (Echinochloa crusgalli var. fiurnentacea(Roxb) Wight) based on seeding date in Jeju region, seeding carried out the 10-day intervals from March 27 to September 30 in 2000, respectively. Plant height was 143.2 cm, showing the highest on seeding date, April 6 among that of any other seeding date. On the other hand, those of early and late seeding gradually decrease. Plant height was 119.2 an in May 16 seeding. The results of stem diameter, number of withering leaves, number of leaves and fresh weight per plant were similar to those of the plant heights. The yield of fresh, dry matter forage, crude protein and TDN found the highest on April 6 seeding, 63.5 MT/ha, 13.9 MTha, 1.1 MT/ha, and 7.6 MT/ha, respectively. In early and late seeding, the yield was gradually decreased. In seeding May 16, the yield found .38.2 MTIha in fresh forage, 6.2 MTha in dry matter forage, 0.7 MT/ha in crude protein and 3.7 MTha in TDN, respectively. According to delaying the seeding date, March 27 to May 16, the contents of crude protein (from 7.9 to 10.8%), ether extract (from 4.6 to 6.0%), nitrogen free extract (from 45.1 to 46.5%), and TDN (from 54.2 to 60.8%) were gradually increased, respectively. On the other hand, those of crude fiber (from 28.9 to 25.6%) and crud ash (from 13.5 to 11.2%) were decreased. These results showed that April 6 was the optimum seeding date with the sole object of feed production of Jeju barnyard grass under the environmental condition like as atmospheric phenomena and soil in Jeju region. (Key words : Jeju barnyard grass, Seeding date, Forage yield, Chemical composition)

• KSBB Journal
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• v.18 no.6
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• pp.490-494
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• 2003

For the production of antifungal compound, strain B-1 was used as a strong producing strain among bacteria isolated from various soil samples. The optimum medium for the production of antifungal compound was PDB (potato starch 0.4%, dextrose 2％, pH5.1). The optimum conditions for the production of antifungal compound didn't affect on the carbon and nitrogen sources. The produced compound showed broad antimicrobial activity to the tested strains such as five fungi and four bacteria. The optimum pH and temperature of the production antifungal compound were pH 5.0 and 28$^{\circ}C$, respectively. Ether extrct (1$\mu\textrm{g}$/${\mu}\ell$) of culture broth was confirmed inhibitory zone by the thin layer chromatography and plate assay. The antimicrobial compound was unstabled after heat (121$^{\circ}C$) trsatment. Strain B-1 was mass cultured in a 5-liter tormentor, containing 3 liters of PDB medium at 28$^{\circ}C$, pH 5.0, 120 (pm with aeration (1L/min).

• Archives of Pharmacal Research
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• v.19 no.2
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• pp.153-159
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• 1996

A new streptothricin family antibiotic producing Streptomyces spp. SNUS 8810-111 was isolated from a soil sample. Study of its morphological and physiological characters indicated that the antibiotic producing organism was a Streptomyces spp. Taxonomical studies suggested that the organism might belong to the genus streptomyces gougeroti. The organism produced antibiotics most in calcium carbonate-tryptic soy broth. The active principles were recovered from the broth with a cation exchange resin and eluted from the resin with HCI. Cellulose column chromatography gave two active principles.$^1H-^1H$ Homo-COSY study on the first compound revealed four structural components. Total hydrolysis of the antibiotic with HCI allowed isolation of $\beta-lysine$. From these data the antibiotic was found to be streptothricin D. The other compound showed one additional signal in the .$^1H$NMR and the $^{13}C$ NMR spectra. The signal was from a methyl group attached to a nitrogen atom. Comparison of the NMR signals with those of streptothricin D suggested that the compound was N-methyl-streptothricin D which was a new compound in the family of streptothricin antibiotics.

• Korean Journal of Food Science and Technology
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• v.3 no.2
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• pp.89-93
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• 1971

Microorganisms producing milk-clotting enzyme were isolated from 1,506 strains which were collected from soil on the various places of Korea, and from strains which were already identified. Dothiorella ribis was taken as a good strain producing milk-clotting enzyme. When it is cultured on wheat bran, the optimum experimental conditions for the production of milk-clotting enzyme were consequently obtained as follows: 1) $30{\sim}35^{\circ}C$ of temperature and 4.0 of pH. 2) $60{\sim]80%$ of cultivating water to the weight of wheat bran. 3) addition of $(NH_4)_2SO_4$ as a nitrogen source, $NaCl\;and\;KH_2PO_4$ as an inorganic salt, and 3% of sucrose as a carbon source. 4) four days for a period of cultivation.

• Journal of Life Science
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• v.13 no.2
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• pp.214-222
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• 2003

The microorganism isolated from soil was identified as Bacillus coagulans by morphological and biochemical analyses and API-50CH/B kit, which was an identification kit for Bacillus species, and named as B. coagulans DL-1. It produced an extracellular biopolymer. Maximum production of biopolymer was 5.00 $\pm$0.15 g/$\ell$ in a $7\ell$bioreactor with an aeration rate of 1.0 vvm and an agitation speed of 500 rpm when concentrations of glucose and yeast as the optimal carbon and nitrogen sources were 2.0% (w/v) and 0.25% (w/v), which were optimized with a flask scale. Gas chromatographic analysis showed that the biopolymer producded by B. coagulans DL-1 consisted of glucose and rhanmose and their molar ratios was about 9 : 1. Its average molecular weight was 2.80$\times$$10^5$ with gel permeation chromatographic (GPC) analysis.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.798-804
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• 2007

A Actinomycetes F-97 producing tyrosinase inhibitor was isolated from soil samples. The optimum culture condition for 쇼rosinase inhibitor production was investigated and the results were as follows. The best carbon source for tyrosinase inhibitor production was shown as soluble starch, the optimum concentration was 3.0%. The best nitrogen source for tyrosinase inhibitor production was shown as peptone, the optimum concentration was 0.36%. As effect of metal ions on the production of tyrosinase inhibitor, K$_2$HPO$_4$ was shown the best and the optimum concentration was 0.1 mM. The optimum pH and temperature was shown 7.0 and 30${\circ}$C, respectively. And the highest tyrosinase inhibitor production was observed at 70hr cultivation under optimum conditions in jar fermentor scale.

• Korean Journal of Microbiology
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• v.21 no.4
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• pp.191-196
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• 1983

A Corynebacterium sp. capable of utilizing diaminododecane (DAD) were isolated from the soil by enrichment culture. Among 9 different kinds of substituted alkanes containing CN, $NH_2$, Cl, and SH groups (monoterminally or diterminally substituted) tested as carbon source, the isolate, designated as DAD 2-3, utilized DAD, putrescine dihydrochloride, dodecane and laurylamine. Dodecanethiol, thioanisole, decanedithiol, dicyanooctane, laurylcyanide,and dichlorodecane were not utilized. When emulgen 950 was added to the medium, the growth of DAD 2-3 was slightly accelerated. Isolate DAD 2-3 grown in the medium with DAD as carbon source formed .alpha.-ketoglutaric acid. Metabolic product of DAD 2-3 grown in a medium without nitrogen source was different from that of grown in a medium with $NH_4NO_3$. When glucose, putrescine, n-dodecane and other alkane derivatives were tested in place of DAD, isolate DAD 2-3 yielded products different from those they formed with DAD suggesting specificity of DAD as a carbon source.

• Journal of Environmental Science International
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• v.16 no.11
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• pp.1219-1223
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• 2007

The removal of nitrogen compounds from a wastewater is essential and it is often accomplished by bio-logical process. An aerobic nitrate-removing bacterium was isolated from a municipal sewage treatment plant and soil. On the basis of its morphological, cultural and physiological characteristics and 16S rRNA sequencing data, this strain was identified as Pseudomonas fluorescens, and named as P. fluorescens K4. The optimal conditions of the initial pH and temperature of media for its growth were $7.0{\sim}8.0$ and $30^{\circ}C$, respectively. P. fluorescens K4 was able to remove 99.9% of nitrate after 24 h in a culture. The strain could grow with a nitrate concentration up to 800 mg/l and was able to remove 99.9% of nitrate after 104 h of incubation. The optimal electron donor was sodium citrate for a nitrate removal. The strain K4 showed a capability of a complete nitrate removal when the initial C/N ratio was 1.0. An effect of the initial seed concentration was observed for a cell of 10% (v/v) for a nitrate removal. Especially P. fluorescens K4 could completely remove 200 mg/l ammonium for 3 days.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.189-195
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• 2002

Using Streptomyces sp. YU100 isolated from Korean soil, the fermentative production of phospholipase D was attempted along with its purification and characterization studies. When different carbon and nitrogen sources were supplemented in the culture medium, glucose and yeast extract were found to be the best. By varying the concentration of nutrients and calcium carbonate, the optimal culture medium was determined as 2.0% glucose, 1.5% yeast extract, 0.5% tryptone 0.3% calcium carbonate. During cultivation, the strain secreted most of the phospholipase D in the early stage of growth within 24 h. The phospholipase D produced in the culture broth exhibited hydrolytic activity as well as transphosphatidylation activity on lecithin (phosphatidylcholine). In particular, the culture broth showed 8.7 units/ml of hydrolytic activity when cultivated at $28^{\circ}C$ for 1.5 days. The phospholipase D was purified using 80% ammonium sulfate precipitation and DEAE-Sepharose CL-6B column chromatography, which produced a major band of 57 kDa on a 10% SDS-polyacrylamide gel with purity higher than 80%. The enzyme showed an optimal pH of 7 in hydrolytic reaction, and at pH 4 in a transphosphatidylation reaction. The enzyme activity increased until the reaction temperature was elevated to $60^{\circ}C$. The enzyme was relatively stable at high temperatures and neutral pH, but significantly unstable in the alkaline range. Among the detergents tested as emulsifiers of phospholipids, the highest enzyme activity was observed when 1.5% Triton X-100 was employed. However, no inhibitory effect by metal ions was detected. Under optimized reaction conditions, the purified enzyme not only completely decomposed PC to phosphatidic acid within 1 h, but also exhibited higher than 80% conversion rate of PC to PS by transphosphatidylation within 4 h.

• Proceedings of the Korean Society of Crop Science Conference
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• 1998.10a
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• pp.288-312
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• 1998

In Korea, chemical fertilizers and agricultural chemicals have had a significant impact on food production and these are today thought to be an indispensable part of modern agriculture. On the other hand, socioeconomical and IMF and WTO status in Korea are constant reminders of the vulnerability of our fossil fuel dependent agriculture. A new crop production system to improve economic, environmental and production efficiency must be exploited. Our particular concern has been given to an integrated cropping system involving recycling of crop residues, soil and N management, biological N fixation and multipurpose legumes. As a new integrated crop production system, a no-till direct-sown rice-vetch relaying cropping system has been proposed in this paper. The formulation of this system is based on the conception that N fertilizers being neither limitlessly available nor affordable, the current high-input crop production systems have produced troubled results severe labour shortage ill rural areas, balance of payment, environmental degradation and reduction of human health far exceed economic concerns. A natural and logical consequence is that long-term sustainability of agricultural systems must rely on the use and effective management of internal resources. Based on the information obtained throughout a series of experiments last years we have proved that the no-till direct-sown rice-vetch relaying cropping system dictates biological alternative which can augment, and in some cases replace, N fertilizers. Comprehensive discussions were made for the proposed system and it concluded that the system can offer an economically attractive and ecologically sound means of reducing external nitrogen input and improving the quality and quantity of internal resources, and consequently improving the farmers as well as the national returns.