• Korean Journal of Food Science and Technology
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• v.7 no.1
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• pp.22-29
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• 1975

Conditions for submerged culture of Agaricus campestris var. bisporus and the chemical composition of its mycelium were investigated. In shaking culture with TGY basal medium at $27{\sim}30^{\circ}C$, pH tended to increase upon culture period, mycelial growth was the highest on 12th day, with relatively high nitrogen content of 7% and sugar in the medium disappeared almost at the end of culture period. As a nitrogen source, ammonium phosphate (dibasic) gave relatively high mycelial yield and the addition of yeast extract gave rise to better results. As a carbon source, glucose was the best, fructose, maltose, lactose and sucrose gave the same results, and soluble starch was utilized slightly. Mushroom mycelium contained 48% of protein, 8 free amino acids including arginine, histidine, lysine, isoleucine, leucine, phenylalanine, proline, tyrosine and its protein consisted of most essential amino acids, with relatively high contents of lysine and threonine. Therefore, mushroom mycelium deserves to be a high quality protein food.

• Journal of Life Science
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• v.31 no.7
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• pp.641-653
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• 2021

The purpose of this study was to confirm the antifungal activity, plant growth-promoting activity, and mineral solubilizing activity of 18 types of bacteria isolated purely from rhizosphere soil. The potential of isolates of the genus Bacillus and Pseudomonas as biocontrol agents was confirmed through the antifungal activity of these isolates. This activity has been determined to be due to various hydrolytic enzymes on the cell wall of plant pathogenic fungi and the production of siderophores in isolates. In addition, most of the isolates have been found to have aminocyclopropane-1-carboxylate deaminase production activity, indole-3-acetic acid production activity, and nitrogen fixation activity. These characteristics are believed to have a positive effect on root development, growth, and the productivity of crops via a reduction in the concentration of ethylene under conditions of environmental stress, to which plants are commonly exposed. In addition, on testing for the solubilizing activity of the isolates for phosphoric acid, silicon, calcium carbonate, and zinc, some isolates were found to have mineral solubilizing activities. Inoculation of these isolates during plant growth is expected to assist plant growth by converting nutrients necessary for growth into usable forms that can be absorbed by plants. The 18 isolated strains can be used as biocontrol agents due to their antifungal activity, plant growthpromoting activity, and mineral solubilizing activity.

• Journal of Applied Biological Chemistry
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• v.52 no.4
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• pp.205-211
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• 2009

This study was carried out to acquire basic data for industrial production of Korean traditional kanjang (soy sauce). Five types of meju, $23{\times}11{\times}12$ ($L{\times}W{\times}H$, cm), $23{\times}11{\times}7$, $15{\times}11{\times}7$, $11{\times}11{\times}6$, $11{\times}11{\times}6$ (made a hole $\varphi$ 1.5 cm) were prepared. The temperature and humidity of meju preparation were $15{\sim}20^{\circ}C$ and 40~50% respectively. The smaller size of meju, the lower free amino acid and non-volatile organic acid content of that. And, two types of meju, conventional method (CM-meju, the temperature and humidity were prepared at $15{\sim}20^{\circ}C$ and 40~50% of relative humidity) and improved method(IM-meju, the temperature and humidity were prepared at $25{\sim}30^{\circ}C$ and 80~90% of relative humidity) for kanjang production were prepared. There was no difference of total nitrogen content and soluble nitrogen content in the size of meju. In total free amino acid content and total free sugar content, IM-meju was the higher than CM-meju. So, the quality of IM-meju was better than that of CM-meju.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.515-521
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• 1997

Tobacco plant was grown for 40 days hydroponically in nutrient solutions composed of different forms of nitrogen, like NO$_3$$^{[-10]}$ -N, NH$_4$$^{＋}$-N, and a mixed formulation of NO$_3$$^{[-10]}$ -N and NH$_4$$^{＋}$-N. Uptake response, nitrate reductase, and glutamine synthetase activity at growth stage were investigated to understand the basic knowledge of nitrogen metabolism. The better growth of shoot and root was observed in the mixed nutrient solution than NO$_3$$^{[-10]}$ -N or NH$_4$$^{＋}$-N, alone. The plant growth in NH$_4$$^{＋}$-N nutrient solution was poor due to ammonium toxicity. The pH of nutrient solution containing NO$_3$$^{[-10]}$ -N increased up to 40 days after transplanting. But the pH of solution containing NO$_3$$^{[-10]}$ -N decreased drastically to 3.42 at 20 days after transplant. The pH in the mixed formulation dropped to pH 3.64 at 30 days after transplant and showed re-increase. It is assumed that nitrogen of NH$_4$$^{＋}$-N form was taken up preferentially at early stage and NO$_3$$^{[-10]}$ -N form was taken up preferentially at middle stage in the treatment with the mixed solution. The result indicates that the relative proportion of nitrogen forms affected the uptake patterns at each growth stages. The contents of chlorophyll and soluble protein were high with the mixed solution. Total nitrogen content was the highest in NH$_4$$^{＋}$-N solution and the content also increased by the application of the mixed type of nitrogen. The amount of nitrate in leaves was high in NO$_3$$^{[-10]}$ -N treatment and the amount of ammonium was high in NH$_4$$^{＋}$-N treatment. The activity of nitrate reductase or glutamine synthetase was highest in the leaves grown in mixed nutrient solution than in those with any other single of nitrogen form.

• Applied Biological Chemistry
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• v.14 no.3
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• pp.191-200
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• 1971

As a series on the soy-bean protein and their related substances 9 samples were collected from 9 places such as straws (Rice) to obtain bacterial strains which produce protease. From these samples total of 23 strains were isolated by the use of dilution pour plate method. For all isolated strains primary screening of productivity of protease was performed and useful straines with regard to protease productivities were identified. Optimum conditions for enzyme action of protease from isolates $D_9$, $F_{20}$ strains were pH 7.5 and $40^{\circ}C$. Chung-Kook-Jang is one of the characteristic foods in Korea made from soy-bean by fermentation. The chief bacterium is Bacillus subtilis and the chief change which takes place in soy-bean during fermentation is degradation of protein. Three kinds of Chung-Kook-Jang were prepared using three different strains of Bacillus natto, $D_9\;and\;F_{20}$ from isolated. Water soluble-N, TCA soluble-N, amino-N and peptide-N were measured about the steamed soybean, Chung-Kook-Jang prepared with three strains of bacteria. Water soluble-N decreased very largely in steamed soybean, but in Chung-Kook-Jang it increased to 85% of raw soy-bean.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.2
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• pp.71-76
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• 2003

In order to determine the influence of nitrogen on agronomic characters, forage yield and quality, Jeju Italian millet(Setaria italica Beauvis) was grown on the volcanic ash soil at the Experimental Farm of Cheju national university under the six levels of nitrogen rates (0, 50, 100, 150, 200, 250kg/ha) from May 1, 2000 to August 25, 2000. Days to heading was delayed 92∼98 days as nitrogen rate increased. Plant height was 96cm at 0kg N/ha. as N rate increased, grew gradually, was 134cm at 200kg N/ha, 135cm at 250kg N/ha, and was not significantly affected between the two plots. Fresh forage, dry matter, crude protein and TDN yield increased 18.88∼42.82MT/ha, 8.45 ∼12.25MT/ha, 0.76∼1.59MT/ha and 4.32∼6.79MT/ha, respectively, as the increasing of N rate, but were not significant between 200kg N/ha and 250kg N/ha. As N rate increased, crude protein, crude fat, NFE and TDN content increased 9.0∼13.0%, 1.4∼1.7%, 9% and 51.1∼55.5%, respectively, but crude ash and crude fiber content decreased 8.7∼8.2% and 34.9∼30.2%, respectively.

• Korean Journal of Agricultural Science
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• v.18 no.1
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• pp.21-32
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• 1991

This experiment was carried out to examine sensory testing for Mozzarella cheese, process cheese, Cheddar cheese and Cheddar cheese made with red pepper, garlic, ginger and welsh onion to develop new cheese varieties which can be prefered by Korean. The chemical composition and sensory testing of cheese were measured. The results were summarized as follows ; 1. Total nitrogen percentages in Cheddar cheese and spiced Cheddar cheeses were similar but those in process cheese and Mozzarella cheese were low. 5% NaCl soluble nitrogen percentages were highest in Cheddar cheese. 5% NaCl soluble nitrogen percentages in each cheese were different. Ripening degree, water soluble nitrogen, TCA soluble nitrogen and SSA soluble nitrogen percentages in each cheese were similiar level. 2. Spiced Cheddar cheeses were more breakdown than other cheese and ${\alpha}_s$-casein breakdowns faster than $\beta$-casein. 3. In the result of sensory evaluation, color score was high in Mozzarella cheese and process cheese. The color score of Cheddar cheese was high in 30's-40's and 50's- 50's. The color score of 10's and 20's was high in Cheddar cheese made with garlic. 4. Odor score was high in Mozzarella cheese and process cheese, too. The odor score of Spiced Cheddar cheeses was high in 10's. 5. Texture score was high in Mozzarella cheese, process cheese and Cheddar cheese. 6. Teste score was high in Mozzarella cheese, process cheese and Cheddar cheese. The taste score of spiced Cheddar cheese was higher in 10's and 20's than that in 30's-40's and 50's-50's.

• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.656-666
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• 1996

Aspen demand has increased recently in the Great Lakes region in the United States. Since aspen has moved into the region in late 1800's, its growing stock has increased so as to change forestry industry of the Lake States. Intensive timber harvesting and biomass removal may cause nutrient depletion, especially on nutrient-poor sites. Forest nutrients and nutrient cycling were investigated in aspen stands of 7-10, 27-33, and 41-42 year-old growing on sandy soils in Minnesota. Nutrients added to the aspen stands by atmospheric deposition and soil weathering were efficiently absorbed and stored in the tree biomass. Aboveground biomass increased from $24.4t{\cdot}ha^{-1}$ at young stands to $139.2t{\cdot}ha^{-1}$ at mature stands. Nutrients accumulated in the tree biomass showed same magnitude of difference. Nutrients added to the site through atmospheric deposition were in the order of Ca, N, K, Mg, and P. Annual litterfall was greater in older stands. However, the amount of nutrients returned by litterfall was not significantly different among stand ages due to the greater nutrient contents in the litterfall of young stands. Litter decomposition and nutrient release rates were greater at young stands than at older stands. Likewise, nutrient availability was higher in young aspen stands and became lower as the stands grew older. Nutrient leaching loss was minimal at all stand ages. Soil N mineralization was greater at young stands than at older stands. Nutrient cycling process was facilitated in young aspen stands with an increased level of available nutrients, Based on the estimations of nutrient balance and nutrient removal by harvesting, Ca was the most critical element which was likely to be depleted if aspen stands are intensively harvested with short rotations.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.105-110
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• 1988

The production of single cell protein using the amylolytic fusant obtained from cell fusion between Hansenula anomala and Saccharomyces cerevisiae was studied. The fusant12 strain was selected for single cell protein production from starchy materials among five fusants. Optimum nitrogen source and its concentration for the growth of fusant12 were ammonium sulfate and 0.1%, respectively. Optimum concentration of soluble starch and optimum pH of the basal medium were lord and pH 5.6, respectively. Autolysis of fusant12 was effectively carried out by addition of 5% (v/v) ethyl acetate to the cell suspension and liquidization for 30 min before incubation for 24 hr at 3$0^{\circ}C$. Coculture of fusant12 and non-amylolytic yeast, Torulopsis candida YA-l5, resulted in the increase of the mass as compared to the monoculture of fusant12. The cell mass on tapioca medium was increased about 2.5 times as on soluble starch medium. The content of crude protein and nucleic acid of the dry cell were 39% and 5.8%, respectively.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.23-28
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• 1984

Anchovy homogenates with or without salt were autolyzed at various pH and temperature conditions. In the initial hydrolysis during 20 hours, the highest autolysis of anchovy homogenate was achieved at pH 4 and $50^{\circ}C$. However, the addition of 20% salt changed the optimum condition to pH 6 and $50^{\circ}C$. When the digestion time was prolonged to 8 days, the most favorable temperature for the autolysis of salted anchovy was lowered to $40^{\circ}C$ compared with $50^{\circ}C$ of initial hydrolysis while the optimum pH was unchanged. Under the best conditions described above, 60.5% of anchovy nitrogen was converted to TCA-soluble nitrogen in 20 hr-incubation without salting, but it was reduced to 49.8% with salting. In the 8 days hydrolysis of salted anchovy, as much as 83.1% of total nitrogen was transformed into TCA-soluble nitrogen. Slight increase in the degree of hydrolysis up to 89.6% was occurred during subsequent ripening period of 52 days at ambient temperature.