• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.30-39
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• 2020

A new silicate coating technology was developed which reduces the impact of dust and loosening during seeding compared to existing silicate-coatings (Seed/Si/Zeolite), and therefore can lower the production costs of rice cultivation. In this method, 100 g of rice seed is coated with 18 mL of liquid silicic acid and then dressed with a mixture containing 80 g of dolomite and 5 g of iron. To determine the most effective method of application and ensure that seedlings developed healthily, a series of experiments were carried out. Infected seeds scattered in seedling boxes and pots (soil and hydroponic) were coated dry, without disinfection. In comparison to the seed which were not treated with the silicate-coating, the new seed (A) were 1.84 times heavier in weight, and were also improved in terms of coating strength and coating color. Compared to the seedlings grown from the non-coated seed, those grown from the new silicate-coated seed were of significantly higher quality (weight/length) and had erect, dark greenish leaves, which are ideal plant characteristics. This was most likely due to increased silicate uptake. The symptoms of bakanae disease in the non-coated seed peaked after 38 days to 54.2%, whereas the control value was 68.8% in the new silicate-coated seed (A). In the infected seedlings grown from the new silicate-coated rice seed, subnormal macro-conidia, namely, a sickle shape spore without a septum; a straight oblong shape spore without a septum and with a thick cell wall; and inter-septal necrosis of a normal spore were detected. It is believed that the strong alkalinity of silicic acid have acted as unfavorable conditions for pathogenicity. In seedlings grown from the new silicate coated rice seed under hydroponic conditions without nutrients, normal root activity and growth was maintained without leaf senescence. Therefore, it was possible to reduce the rate of fertilization. In the future, a new silicate-coated rice seed was required for the study of minimal nutrition for anti-aging of seedlings.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.249-254
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• 2002

To determine the abilities as both lactic starter and probiotics for fermented foods, we investigated the potency of acid production, proteolytic activity and lactose metabolism of Lactobacillus amylovorus IMC-1. And the strain was cultured with lactococci in 10% skim milk medium. It was also examined the bactericidal action of antibacterial substance, produced by the strain IMC-1, against pathogenic bacteria. L. amylovorus IMC-1 showed excellent production of acid in 10% skim milk supplemented with yeast extract, and produced 0.8 and 2.7% of acid at 12 and 72 h incubation, respectively. It was found that the activity of ${\beta}-galactosidase$, about $39\;{\mu}M/minute/dry$ cell weight (mg), was stronger than that of $phospho-{\beta}-galactosidase$ in the strain IMC-1. The strain showed weak proteolytic activity in 10% skim milk, thus it produced 6 and $69\;{\mu}g/mL$ of free tyrosine at 12 and 72 h cultivation, respectively. It was known that the strain utilized mainly ${\alpha}-casein$ than ${\beta}-casein$ from patterns of SDS-PAGE. Mixed culture produced more acid than single cultures of L. amylovorus IMC-1 and Streptococcus thermophilus NIAI 510. Single culture of Str. thermophilus and mixed culture showed increasing cheese flavor with incubation times. Optimal fermentation time of mixed culture for the acid production and flora of lactic starter was 16 and 12 h by adding 0.1 and 0.5% of yeast extract to 10% skim milk, respectively. Antibacterial substance produced by the strain IMC-1 reduced about 2 log of the viable cell counts of both Escherichia coli O157 and Shigella flexneri after 24 and 4 h incubation, and they were not detected after 48 and 6 h incubation, respectively.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.67-73
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• 2005

Photoautotrophic bacteria are promising candidates for the production of poly(3-hydroxybutyrate) (PHB) since they can address the critical problem of substrate costs. In this study, we isolated 25 Tn5-inserted mutants of the Synechocystis sp. PCC 6803 which showed enhanced PHB accumulation compared to the wild-type strain. After 5-days cultivation under nitrogen-limited mixotrophic conditions, the intracellular levels of PHB content in these mutants reached up to $10-30\%$ of dry cell weight (DCW) comparable to $4\%$ of DCW in the wild-type strain. Using the method of inverse PCR, the affected genes of the mutants were mapped on the completely known genome sequence of Synechocystis sp. PCC 6803. As a result, the increased PHB accumulation in 5 mutants were found to be resulted from defects of genes coding for NADH-ubiquinone oxidoreductase, O-succinylbenzoic-CoA ligase, photosystem II PsbT protein or histidine kinase, which are involved in photosystem in thylakoid inner membrane of the cell. The values of $NAD(P)H/NAD(P)^+$ ratio in the cells of these mutants were much higher than that of the wild-type strain as measured by using pulse-amplitude modulated fluorometer, suggesting that PHB synthesis could be enhanced by increasing the level of cellular NAD(P)H which is a limiting substrate for NADPH-dependent acetoacetyl-CoA reductase. From these results, it is likely that NAD(P)H would be a limiting factor for PHB synthesis in Synechocystis sp. PCC 6803.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1727-1734
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• 2005

The fermentation characteristics and mono- and di-saccharides compositions during the early stage of ensiling were studied with a temperate grass, Italian ryegrass (Lolium multiflorum Lam.) and a tropical grass, guineagrass (Panicum maximum Jacq.). The laboratory silos were kept in the room set at 25$^{\circ}C$, and then were opened on 0.5, 1, 2, 3, 5 and 7 days (14 days in Italian ryegrass) after ensiling, respectively. The Italian ryegrass silage showed a fast and large pH decrease caused by a fast and large production of lactic acid during the first 5 days of ensiling and succeeded to achieve lactic acid type fermentation; high lactic acid/acetic acid and lactic acid content at the end of ensiling (14 days), low values of pH (3.74), acetic acid, ethanol and ammonia-N/total nitrogen, none or only small amounts of Butyric acid, valeric acid and propionic acid. The guineagrass silage showed a slow decrease in pH and a slow increase in lactic acid content during the full ensiling period, causing a high final pH value, low contents of lactic acid, acetic acid, total volatile fatty acids and total organic acids. In Italian ryegrass silage, mono- and di-saccharides compositions decreased largely within the initial 0.5 day (12 h) of ensiling. Sucrose disappeared rapidly within the initial 0.5 day of ensiling, but fructose and glucose contents showed an initial rise by the activity of enzymes in plant tissues, and then decreased gradually. On the other hand, the contents of monoand di-saccharides in guineagrass showed the largest decreases due mainly to plant respiration within the initial 0.5 day of ensiling, and no initial rises in fructose and glucose contents during the early stage of ensiling because of the absence of fructans which are hydrolyzed into fructose and glucose in temperate grasses. In both silages, the rate of reduction in mono- and di-saccharides compositions within the initial 5 days of ensiling was ranked in the order of glucose>fructose>sucrose, suggesting that glucose and fructose might be more favorably utilized than sucrose by microorganisms and glucose is the first fermentation substrate. It was concluded that the silage made from Italian ryegrass with high moisture content had a good fermentation quality owing to the dominance of lactic acid bacteria and active lactic acid fermentation during the initial stage of ensiling. These results can be explained by rapid plant sap liberation and the high activity of plant enzyme hydrolyzed fructans into fructose and glucose within the initial 2 days of ensiling, which stimulate the homofermentative lactic acid bacteria growth. In ensiling a temperate grass, the physical characteristics may ensure the rapid onset of fermentation phase, which results from the smaller losses of water-soluble carbohydrates during the initial stage of ensiling and providing sufficient water-soluble carbohydrates for lactic acid bacteria. The silage made from guineagrass with intermediate dry matter and high initial mono- and di-saccharides content was stable silage. This could be explained by the higher incorporation of air during the very early stage of ensiling and the restriction of cell breakdown and juice release due to the properties of a tropical grass with coarse porosity and stemmy structures. These physical characteristics delayed the onset of lactic acid bacteria fermentation phase by extending the phases of respiration and aerobic microorganisms activity, causing the higher loss of water-soluble carbohydrates and the shortage of lactic acid bacteria fermentation substrates.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.463-469
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• 2014

Sorghum has been consumed as one of the important staple food in the semiarid tropics of Africa and Asia. Sorghum is rich in starch, protein, essential vitamins and minerals and grows relatively well in dry climate regions when it compared with other staple food crops. Sorghum has taken an increased interest due to several studies that report about the beneficial effects of sorghum on human health. In the present study, we investigated the antioxidative and activity of extract of milling by-products (hull and bran) of Korean sorghum cultivar, 'Hwanggeaumchal' as well as its grain. Hull extract showed the highest total polyphenol contents ($29.7{\pm}0.2mg\;GAE/100g$) and major four pigments content ($322.6{\pm}14.5mg/100g$). From results of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate (ABTS) radical scavenging activity, hull extract ($IC_{50}$, $6.3{\pm}0.1{\mu}g/mL$) was also showed the strongest antioxidative effects. Bran and grain showed similar polyphenol, pigments contents and antioxidative effects. We determined cell viability by MTT assay and evaluated the anti-inflammatory activity by measuring nitric oxide (NO) of hull, bran and grain methanol extract (0.5% HCl v/v) on RAW 264.7 cells. Hull extract treatment was significantly decreased NO production with dose-dependant manner. Apigeninidin as one of the major pigment of hull was showed inhibitory activity against NO production without cytotoxicitiy. Therefore, sorghum milling by-products can be used as a good source of antioxidative and anti-inflammatory agents.

• Applied Microscopy
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• v.30 no.4
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• pp.347-355
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• 2000

Zinc is one of the most abundant oligoelements in the living cell. It appears tightly bound to some metalloproteins and nucleic acids, loosely bound to some metallothioneins or even as free ion. Small amounts of zinc ions (in the nanomolar range) regulate a plentitude of enzymatic proteins, receptors and transcription factors, thus rolls need accurate homeostasis of zinc ions. Zinc is an essential catalytic or structural element of many proteins, and a signaling messenger that is released by neural activity at many central excitatory synapses. Growing evidences suggest that zinc may also be a key mediator and modulator of the neuronal death associated with transient global ischemia and sustained seizures, as well as perhaps other neurological disease stoles. Some neurons have developed mechanisms to accumulate zinc in specific membrane compartment ('vesicular zinc') which can be evidenced using histochemical techniques. Substances giving a bright colour or emitting fluorescence when in contact with divalent metal ions are currently used to detect them inside cells; their use leads to the so called 'direct' methods. The fixation and precipitation of metal ions as insoluble salt precipitates, their maintenance along the histological process and, finally, their demonstration after autometallographic development are essential steps for other methods, the so called 'indirect methods'. This study is a short report on the autometallograhical approaches for zinc detection in the central nervous system (CNS) by means of a modified selenium method.

• Tuberculosis and Respiratory Diseases
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• v.43 no.4
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• pp.579-589
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• 1996

Background : Activation of neutrophil is critical for the clearance of microorganisms and toxic host mediators during sepsis. Unfortunately the activated neutrophil and its toxic byproducts can produce tissue injury and organ dysfunction. The leucocyte CD11/18 adhesion complex regulates neutrophil-endothelial cell adhesion, the first step in neutrophil migration to sites of injection and inflammation. To investigate the potential of neutrophil inhibition as a treatment strategy for sepsis, we evaluated the effects of monoclonal antibody against CD11b (MAb 1B6) in rats intrabronchial challenged with Escherichia coli. Methods : Animals were randomly assigned to receive monoclonal antibody against CD11b (1 mg/kg, sc) and bovine serum albumin(BSA, 1 mg/kg, sc) 6 hr before, at 0 and 6 hr after intrabronchial challenge of $20x10^9$ CFU/kg E. coli 0111. Animals were randomized to treat either 24, 60 or 90% oxygen after bacterial challenge and begining 4 hr after inoculation, all animals were received 100 mg/kg ceftriaxone qd for 3 days. Peripheral and alveolar neutrophil(by bronchoalveolar lavage) counts and lung injury parameters such as alveolar-arte rial $PO_2$ difference, wet to dry lung weight ratio and protein concentration of alveolar fluid were measured in survived rats at 12 hr and 96 hr. Results : Monoclonal antibody against CD11b decreased circulating and alveolar neutrophil especially more in 12 hr than in 96 hr The lung injury parameters of antibody-treated animals were not different from those of BSA-treated animals. but It was meaningless due to small number of survived animals. The early(6 hr) mortality rate was significantly increased in antibody-treated group(51%) compared to BSA-treated group(31%) (P=0.02) but late(from 12 hr to 72 hr) mortality rate was not different in antibody-treated group(44%) from BSA-treated group(36%) (P =0.089). Conclusion : Leucocyte CD11b/18 adhesion molecule is known to regulate neutrophil migration to the site of infection and inflammation. The monoclonal antibody against CD11b decreased alveolar neutrophil in rats with pulmonary sepsis and increased early mortality rate. Therefore, we can speculate that monoclonal antibody against CD11b blocks of alveolar recruitment of neutrophils, impairs host defense mechanism and increases early mortality rate of pulmonary sepsis in rat.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.2
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• pp.85-91
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• 1988

A field experiment was conduted to determine the effects of shading degrees (O: full sunlight, 25, 50 and 75%) on the proximate components, cell wall constituents (CWC), digestibility, water soluble carbohydrates (WSC) and nitrate nitrogen ($NO_3$-N) concentration of grasses grown in forest. For the test different artificial shading houses were established and pasutre species used were orchardgrass, timothy, perennial ryegrass and ladino clover. the experiment was performed at LES in Suwon, 1985 1. Considering proximate components, CWC and digestibility of grasses, ladino clover showed the best quality, and then perennial ryegrass. 2. The contents of crude protein, crude ash, and digestibility of grasses were increased with shadking, regardless of pasture species. As the shading degrees are increased, the contents of crude fibe in orchardgrass, perennial ryegrass and timothy were decreased, while that in ladino clover was increased with shading. 3. Grasses grwon in spring showed higher digestibility than those grwon in summer season. 4. The content of WSC was the highest in perennial ryegrass, and then ladino clover, orchardgrass, and timothy, in that order. Also WSC was decreased as the shading degrees are in creased. 5. The content of $NO_3$-N was the highest in perennial ryegrass, and then orchardgrass, ladino clover and timothy, in that order. Also the $NO_3$-N was significantly increased with higher shading level. In the regression equation between shading degrees and $NO_3$-N ($r^2=0.90^{**},\;r^2=0.95^{**}$), shading degree of 43 to 44% was critical level, causing nitrate poisoning to animal. 6. Considering grass quality, dry matter yield and $NO_3$-N, less than 40% of shading degree (over 60% of full sunlight) was desirable for better grassland improvement, management and utilization in the forest.

• Journal of Bio-Environment Control
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• v.26 no.1
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• pp.35-42
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• 2017

This research was conducted to investigate the influence of post-planting fertilizer concentrations on the growth of seedlings and changes of nutrient concentrations of media in tomato seedling production through sub-irrigation. Two root media such as peat moss (grade of 0 to 6 mm, PM06) plus perlite (grade of 1 to 2 mm (PE2)(7:3, v/v) and peat moss (grade of 5 to 15 mm, PM515) plus PE2 (7:3, v/v) were formulated and filled into 72-cell plug trays. After seeds of 'Dotaerang Dia' tomato were sown and germinated at $28^{\circ}C$, the trays were moved to greenhouse and seedlings were raised 35 days. When the cotyledons were emerged, post-planting fertilizers of 13-2-13, 15-0-15 and 20-9-20 ($N-P_2O_5-K_2O$) were applied in a sequence. The fertilizer concentrations based on N in each plug stage were differed with $25mg{\cdot}L^{-1}$ in three treatments. The fertilizer solutions were supplied when the weight of plug trays decreased to 40 to 50% compared to container capacity. The root media were collected in 1, 2, 4, and 5 weeks after sowing and were divided into top, middle, and bottom parts, then were analysed for pH, EC and macro-nutrient concentrations. The seedling growth was investigated 5 weeks after sowing. The pH and EC in PM06+PE2 was higher than those of PM515+PE2. The bottom and mid-part had higher pH and lower EC compared to upper part in each medium. The differences of EC between upper and bottom parts were around 2 times in each medium. The $NH_4-N$ and K concentrations in program 3 of PM06+PE2 showed the highest concentrations among all treatments. The $NO_3-N$ concentrations in PM06+PE2 increased gradually and this rising tendency become severe as post-planting fertilizer concentrations were elevated. The seedling growth in terms of fresh and dry weights was the highest in the treatment of program 2 in PM06+PE2 among all treatments tested. Above results indicate that the gradual increases of fertilizer concentrations from 25 to $125mg{\cdot}L^{-1}$ in plug stages 2, 3, and 4 plug stages are desirable for

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.843-859
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• 2017

The JK-1 isolate which was the best producer of indole-3-acetic acid and carotenoid among the 388 strains isolated from 28 wetlands in Jeju, was identified to be Rhodopseudomonas palustirs belongs to a typical group of non sulfur purple bacteria based on 16S sRNA sequencing. This study investigated the effect of different cultural conditions of pH, temperature, agitation, light and aeration on growth, IAA and carotenoid production of photosynthetic bacterium JK-1 for optimization of IAA and carotenoid production. It was found that growth, IAA, carotenoid, and bacteriochlorophyll production with light (3,000~3,500 Lux) and agitation (100 rpm) showed better results than those with dark/static or dark/agitation (100 rpm) in anaerobic conditions. The optimal pH, temperature and agitation speed for cell growth were 7, $30^{\circ}C$, 150 rpm, for IAA production were 9, $30^{\circ}C$, 150rpm and for carotenoid production were 6, $25^{\circ}C$, 50 rpm, cultured for 72 h under anaerobic light, respectively. The growth and IAA production were high in aerobic culture compared with anaerocic culture, whereas carotenoid and bacteriochlorophyll content were decreased extremely in aerobic condition (0.5~1 vvm). Subsequently, the optimal culture conditions for JK-1 were selected with pH 7, $30^{\circ}C$ and 100 rpm under anaerobic light and the effect on plant growth was tested by pot assay. Inoculation of JK-1 with 3% (v/v) level caused increase in shoot and root dry weigh that varied from 20%~58% to 40%~28% in young radish in camparison to uninoculated treatment at 50 days of growth. The study suggests that the JK-1 isolate may serve as efficient biofertilizer inoculants to promote plant growth.