• Korean Journal of Weed Science
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• v.13 no.2
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• pp.96-103
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• 1993

The experiments on the ecological characteristics of the suspensible green algae and the algae causing soil-flakes and shier chemical control were conducted in 1992. The unicellular green algae which were dominated by Chlamydomonas sp. largely occurred when phosphorus was applied, but which were reduced by nitrogen application. The filamentous green algae which were dominated by Klebsormidium sp. largely occurred when phosphorus was applied, and which much more increased when nitrogen or potassium was combined with phosphorus. The suspensible green algae which were dominated by Klebsormidium sp. were controlled by 60-70% when simazine 10g ai/10a and propanil 105g ai/10a were applied. The dark blue soil-flakes largely occurred at nitrogen application, and which much more increased when nitrogen was combined with phosphorus. The dark brown soil-flakes largely occurred at phosphorus application, but no more increased even if nitrogen or potassium was combined with phosphorus. The dark blue soil-flakes which were dominated by Oscillatoria sp. much more increased at the temperature conditions of $18^{\circ}C$ compared with $24^{\circ}C$ and $29^{\circ}C$. The applications of bensulfuron/mefenacet/dymron, piperophos/dimethametryn and bensulfuron/dimepiperate controlled 70-90% of the dark blue soil-flakes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.611-616
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• 2001

The bacteriological and physiochemical analysis of seawater in Tongyeong harbor was conducted to evaluate sanitary conditions, The samples were collected at 6 stations established once a month from January to December, 2000. During the study period, the ranges of temperature, transparency, chemical oxygen demand, dissolved oxygen, dissolved nitrogen, phosphate and chlorophyll-a were $6.8\sim25.2^{\circ}C,\;1.0\sim2.5\;m,\;1.79\sim2.41\;mg/L,\;5.7\sim10.1\;mg/L,\;6.59\sim10.53{\mu}g-at/L,\;0.56\sim1.01{\mu}g-at/L\;and\;1.21\sim9.54\;mg/m^3$, respectively, The viable cell counts of seawater in Tongyeong harbor ranged from $3.0\times10^4CFU/mL\;to\;6.9\times10^6CFU/mL$. The coliform group and fecal coliform MPN's of the samples were ranged $23\~4,600\;MPN/100\;mL$ (means 540 MPN/100 mL) and $11\~1,600\;MPN/100\;mL$ (means 210 MPN/100 mL), respectively, The coliform group was classified with IMViC reactions and pathogenic vibrios were analyzed. Two hundred eighteen strains that were obtained from seawater samples in Tongyeong harbor represented Escherichia coli group, $66.1\%$; Citrobacter freundii group, $11.0\%$; Enterobacter aerogenes, $9.6\%$; and unknown, $13.3\%$, respectively. During the study period, infectious bacteria such as Vibrio cholerae O1, Salmonella sp. and Shigella sp. were not detected from the samples, but detection ratios of V. parahaemolyticus, V cholerae non-O1 and V. vulnificus were $10.0\sim30.1\%$.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.225-231
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• 2006

To investigate the effect of feeding rare earth (RE) on the performance of breeder hens a feeding trial with sixteen thousands of 158 day old Ross broiler breeder hens was conducted for thirty weeks. A mixture of RE- chlorides containing mainly La, Ce, and Pr was mixed into corn-soy based diet at two levels, 300 and 600 mg/kg, All the hens were housed in flat layer houses and the ratio of male to female was maintained at one to ten. Dietary supplementation of the of RE at a level of 300 mg/kg made the hens reach egg production peak higher by about 6% and earlier by about two weeks. As a result, it made higher hatchable egg production by 3.5%. It also reduced dramatically the mortality of both male and female breeders(P<0.05). Egg weight was slightly increased but egg qualify was not much influenced by dietary supplementation of RE. Egg albumin hight and Haugh unit were significantly improved while egg shell thickness, egg breaking strength and yolk color were similar to those of the control. Experimental results appeared to show a good possibility that egg fertility and hatchability were improved by feeding RE. Dietary supplementation of RE at a level of 300 mg/kg should be acceptable but not the 600 mg/kg level for breeder hens. Further studies on the effect of RE on egg fertility and hatchability appears to be necessary.

• Journal of Applied Biological Chemistry
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• v.55 no.3
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• pp.185-189
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• 2012

This study was conducted to investigate the effect of different steam condition and dehydration condition on physicochemical characteristics of Olbyeossal made from Waxy rice. All samples were steamed at $95-100^{\circ}C$ for 60 min or at $121^{\circ}C$ for 20 min and then were dehydrated using hot air 45, 60, $80^{\circ}C$ and sun-dried to achieve moisture contents 13-15%. Initial pasting temperature of Olbyeossal was the lower than that of nontreatment sample by parboiling. The combination in steaming $95-100^{\circ}C$ and hot drying at $45-60^{\circ}C$ was showed appropriate pasting properties compared with other condition. The hardness of Olbyeossal was significantly affected by steaming and dehydration condition. The hardness of Olbyeossal showed the higher value for steaming at $121^{\circ}C$ than $95-100^{\circ}C$. The water binding capacity (WBC) and swelling power (SP) were higher steaming at $121^{\circ}C$ than $95-100^{\circ}C$. No significant differences on WBC and SP of Olbyeossal by dehydration condition were observed. As the sensory evaluation results, the combination in steaming at $121^{\circ}C$ and hot-air drying at 45 or $80^{\circ}C$ led to increase preference for appearance, color, taste and overall acceptability. These results indicate that steaming and dehydration condition were affecting factor on physicochemical characteristics of Olbyeossal.

• Korean Journal of Medicinal Crop Science
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• v.5 no.3
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• pp.237-242
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• 1997

The experiment was conducted to find causes of rooting failure in divided crown of peony cultivation. The results were as follows : In farmer s fields, damage rate of rooting failure in divided crown of peony was 32% as non-sprouting 5.6%, withering after sprouting 20.7%, and wilting after sprouting 5.7%, repectively. Damage degree in farmer s fields was followed, above 70% by 4%, 41 to 70% by 17%, 11 to 40% by 45% per total field area, respectively. It was caused by rooting failure. Damage rate of rooting failure as affected by different planting time was 18.2% for planting in autumn, 42.9% for planting in spring, and damage in divided crown was higher than in seedling. As periods to planting were prolonged, growth and yield were larger poorly, treatment with seminal-root sterilization and soil insecticide showed good growth and rooting but untreated control was very poor. Main cause of rooting failure in divided crown of peony was disease, Cylindrocarpon sp. and low quality of seeds.

• Korean Journal of Microbiology
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• v.43 no.1
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• pp.47-53
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• 2007

The DY1 strain of Gram-positive, rod-shaped bacteria was isolated from the soil sample collected from Daeam mountain, Korea. The culture filtrate of DY1 strain showed a broad spectrum of antimicrobial activity on various pathogenic and food poisoning enteric bacterial species tested in vitro. It showed significant growth-inhibitory effect on Salmonella enterica sp., Shigella sp., pathogenic Escherichia coli, Vibrio cholerae, Vibrio parahemolyticus, and Yersinia enterocolitica. For the identification of the DY1 strain, morphological, biochemical and molecular phylogenetic approaches were performed. The DY1 strain was found to be a member of the genus Paenibacillus on the basis of morphological and biochemical analyses. The 16S rDNA of DY1 showed the highest pairwise identity with Paenibacillus polymyxa with 99.79% (1,413 bp/1,416 bp). The antimicrobial entity from DY1 looked different from preciously reported ones and seems to have a great potential to be further studied as a candidate of new antibiotics to control multi-drug resistant pathogens.

• The Korean Journal of Mycology
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• v.13 no.4
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• pp.203-212
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• 1985

Of 450 strains isolated from the soil microbes collected in various locations in Korea, a strain had a strong inhibitory activity against bacterial ${\alpha}-amylase$ and was named strain DMC-72 of the genus Streptomyces. The amylase inhibitory metabolite produced by this strain was purified by means of acetone precipitation, adsorption on Amberlite IRC-50 and SP-Sephadex C-25. The inhibitor was found to be a derivative of oligosaccharides by spectral and chemical data. The inhibitor was stable at the pH range of $1{\sim}13$ and at $100^{\circ}C$ for half an hour, also inhibited other amylases such as salivary ${\alpha}-amylase$, pancreatic ${\alpha}-amylase$, fungal ${\alpha}-amylase$ and glucoamylase. However, it showed no inhibitory activity against ${\alpha}-glucosidase$, ${\beta}-glucosidase$, dextranase, and ${\beta}-amylase$. The kinetic studies of the inhibitor showed that its inhibitory effects on starch hydrolysis by ${\alpha}-amylase$ were noncompetitive.

• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.142-148
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• 2001

An indigenous antagonistic bacterium Bacillus sp. 7079 was isolated from a local soil sampled at Kyongju area in Korea . The strain has strong antagonistic ability which was originated from multifunctional mechanisms of chitinase and antibiotic and is a powerful antagonistic biocontrol agent against red-pepper rotting fungus Phytophthora capsici and Wilt fungus Fusarium oxysporum. The chitinase might degrade the cell wasll for Fusarium species. The selected Bacilus sp. 7079 was identified as a Bacillus amyloliquefaciens 7079. The maximal production of the chitinase from B, amyloliquefaciens 7079 were obtained in chitin-yeast extract medium containing 0.7%, $K_2$$HPO_4$, $0.2KH_2$$PO_4$, 0.1% ($NH_4$)$_2$$SO_4$, 0.05% sodium cirate, 0.01% $MgSO_4$$7H_2$O, 0.1% yeast extract and 0.1% colloidal chitin after cultivation of 3 days at pH 7.0 and $30^{\circ}C$. The best carbon and nitrogen sources for the production of the chitinase from B amyloliquefaciens 7079 were determined to be 0.1% colloi- dal chitin and 0.15% proteose peptone NO 3 respectively, The antagonistic activity of B amyloliquefaciens 7079 was confirmed using P. capsici by in vivo pot test with red-pepper plant.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.212-218
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• 1999

The effects of gamma irradiation (1, 3 and 5 kGy) and packaging methods (air and vacuum) on the growth of microorganisms contaminated in beef was investigated during storage at different temperatures (-20, 4 and $25^{\circ}C$). The initial microbial population of beef was $8.0{\sim}10^2\;CFU/g$ in total aerobic bacteria, $2.0{\times}10^2\;CFU/g$ in total lactic acid bacteria, $8.0{\times}10^1\;CFU/g$ in molds, $6.0{\times}10^2\;CFU/g$ in Pseudomonas sp. and $7.0{\times}10^2\;CFU/g$ in coliforms, respectively. Gamma irradiation at 5 kGy completely eliminated pathogenic bacteria in beef. Gamma irradiation at such dose and subsequent storage at less than $4^{\circ}C$ could ensure hygienic quality prolong the microbiological shelf-life resulting from the reduction of spoilage microorganisms. The different packaging methods of beef caused negligible changes in the growth of microorganisms during storage.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.406-412
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• 1998

The endoglucanase gene, egl6, of Trichoderma sp. was connected with the yeast ADH1 promoter, and the resultant plasmid, pVT-C4, was introduced into three S. cerevisiae host strains (YNN27, 2805, and SEY2102). Among each 80 transformants, the cell growth and expression level of endoglucanase were compared in test-tube cultivation, and three respective transformants for each host cells showing the highest expression level and cell growth were selected. When three recombinant yeast cells were batchwise cultivated for 48 hr in flask, the total activities of endoglucanase expressed were about 1140 unit/l with 2805/pVT-C4, 1020 unit/l with SEY2102/pVT-C4, and 590 unit/l with YNN27/pVT-C4. Irrespective of host strain, about 80% of the expressed endoglucanase was detected in the extracellular medium. In addition, it was also found that the recombinant enzyme was secreted into the culture medium as two major forms of lightly and heavily glycosylated proteins.