• The Korean Journal of Mycology
• /
• v.23 no.1 s.72
• /
• pp.53-60
• /
• 1995

Nutritional requirements for the growth of Flammulina velutipes were studied. Mannitol, glutamic acid and ammonium nitrate were chosen for the maximum mycelial growth when various carbon and nitrogen sources tested. Optimum C : N ratio for the mycelial growth was 20 : 1. Potassium dihydrogen phosphate was selected among the phosphate sources. Magnesium sulphate and thiamine HCl stimulate mycelial growth. Final compositions of optimized chemically defined medium were 1.5% mannitol, 0.082% $NH_4NO_3$, 0.312% glutamic acid, 0.25% $KH_2PO_4$, 0.06% $MgSO_4{\cdot}7H_2O\;and\;0.3\;{\mu}g/l$ thiamin HCl. This medium not only support mycelial growth but also induce fruit body formation.

• Journal of the Korea Institute of Building Construction
• /
• v.17 no.3
• /
• pp.211-217
• /
• 2017

The objective of this study is to seek a reliable mixture proportion for magnesium potassium phosphate composite(MKPC) mortars with a near-neutral pH value (below 9.5) and a relatively good compressive strength exceeding 30MPa. The main parameter selected was the molar ratios($M_{mp}$) of $MgO-to-KH_2PO_4$ which varied from 30.4 to 3.4. The setting time of the MKPC mortars tended to shorten with a decrease in $M_{mp}$ value. With regard to the strength development ratio normalized by the 28-day strength, the ranges measured in the mortars with an $M_{mp}$ below 7.9 were 50~61% at 1 day and 60~73% at 3 days, indicating a highly rapid early-strength development. With a decrease in $M_{mp}$, the formation of struvite-K crystal identified as a primary hydration product increased, which led to the decrease of the macro-capillary pores in micro-structures. For achieving the targeted requirements for pH value and compressive strength, the $M_{mp}$ needs to be selected as below 5.1.

• Korean Journal of Agricultural Science
• /
• v.3 no.2
• /
• pp.139-144
• /
• 1976

To deter-mine the most reasonable method for improving of newly reclaimed soil, seven kinds of improving methods were tested and the soybean was cultivated as test crop. The results obtained are summarized as follow: The newly reclaimed soil where this experiment was carried out showed low acidity and was deficient in the humus, the phosphate, the calcium and the magnesium. Both the fused phosphate as well as the calcium was much effective to the correction of the soil acidity. The compost was the most effective source to increase the content of the humus in the soil, and also the calcium application showed a significant effect to increase the amount of humus. Not only compost but also fused phosphate were much effective to increase the content of calcium in the soil. Each factor as the calcium, the fused phosphate, the compost and the deep plowing has an effect to increase the amount of magnesium in soil significantly. The compost increased the potassium in soil. The amount of magnesium in soybean plant was significantly increased by the application of the calcium, the fused phosphate or the compost. And the calcium and the fused phosphate had an effect to increase the grain yield of soybean. The highest grain yield of soybean was taken at the treatment of N.P.K.+Compost+Calcium+Deep-plowing. The grain yield of soybean was significantly correlated with the soil acidity, the amount of the humus and the magnesium in soil and the amount of the magnesium in soybean plant.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.27 no.1
• /
• pp.90-97
• /
• 2000

There are various kinds of factors associated with the formation of dental plaque in oral cavity such as nutrient molecules and chemical agents. The factors influencing the formation of insoluble glucan by Streptococcus sobrinus and its replication were examined on orthodontic wires. The results were as follows: 1. Insoluble glucan was well produced in the media initially adjusted at pH 7.0 than pH 5.5 or pH 8.5 like bacterial replication. 2. The synthesis of insoluble glucan and bacterial replication were significantly increased in the media containing 2.5% yeast extract. The formation of insoluble glucan was inhibited by 10 folds in the media containing 20% of sucrose than 1.25%, but the replication of bacteria was increased by 20 folds. 3. Insoluble glucan was significantly formed at a concentration of 1.0mM of calcium chloride, 40mM of potassium chloride, 0.1mM of magnesium chloride, while the replication of bacteria was little influenced by them regardless their concentration. 4. The formation of insoluble glucan and bacterial replication were significant in the media containing 10mM of sodium bicarbonate, but both were completely inhibited at 100mM or above. The production of insoluble glucan and the bacterial replication were largely decreased at 10mM of Tris while insoluble glucan was formed in abundance at 100mM of Tris. 5. The synthesis of insoluble glucan and the bacterial replication were inhibited at 10mM or above of sodium phosphate and potassium phosphate.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.05a
• /
• pp.34-35
• /
• 2016

Most of the construction adhesive may contain harmful component to the human body with an organic adhesive. In addition, when the adhesive caused hydroquinone, alkyl benzophenone, etc, also it raises the skin diseases to workers. Therefore, the inorganic adhesive development is necessary. This study was a study to know adhesive strength properties that adhesive using a magnesium oxide according to the addition ratio of the retarder. It has experiments to two types of magnesium oxide and type and ratio of retarder differently.

• Korean Journal of Soil Science and Fertilizer
• /
• v.41 no.5
• /
• pp.348-353
• /
• 2008

With the aim to explore the possible role of phosphate-solubilizing bacteria in soil, we conducted a survey of phosphate-solubilizing microorganisms colonizing in upland and plastic film house soils. Soil EC, pH, organic matter, available phosphate, exchangeable cation such as potassium, calcium and magnesium, and total P of plastic film house soils were higher than those of upland soils. Phosphate-solubilizing bacteria population was higher in plastic film house soils than upland soils, but species of phosphate-solubilizing bacteria was more diverse in the upland soils than the plastic film house soils. There was significant positive correlation between phosphate solubilization and phosphate-solubilizing bacteria in soils. Bacillus, Cedecea, Brevibacillus, Paenibacillus, Pseudomonas, Serratia spp. were isolated from upland soils and Bacillus and Cellulomonas spp. were from plastic film house soils.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.2
• /
• pp.211-217
• /
• 2013

Corynebacterium glutamicum is one of the well-studied industrial strain that is used for the production of nucleotides and amino acids. Recently, it has also been studied as a possible producer of organic acids such as succinic acid, based on its ability to produce organic acids under an oxygen deprivation condition. In this study, we conducted the optimization of medium components for improved succinate production from C. glutamicum under an oxygen deprivation condition by Plackett-Burman design and applied a response surface methodology. A Plackett-Burman design for ten factors such as glucose, ammonium sulfate, magnesium sulfate, potassium phosphate ($K_2HPO_4$ and $KH_2PO_4$), iron sulfate, manganese sulfate, biotin, thiamine, and sodium bicarbonate was applied to evaluate the effects on succinate production. Glucose, ammonium sulfate, magnesium sulfate, and dipotassium phosphate were found to have significant influence on succinate production, and the optimal concentrations of these four factors were sequentially investigated by the response surface methodology using a Box-Behnken design. The optimal medium components obtained for achieving maximum concentration of succinic acid were as follows: glucose 10 g/l, magnesium sulfate 0.5 g/l, dipotassium phosphate ($K_2HPO_4$) 0.75 g/l, potassium dihydrogen phosphate ($KH_2PO_4$) 0.5 g/l, iron sulfate 6 mg/l, manganese sulfate 4.2 mg/l, biotin 0.2 mg/l, thiamine 0.2 mg/l, and sodium bicarbonate 100 mM. The parameters that differed from a normal BT medium were glucose changed from 40 g/l to 10 g/l, dipotassium phosphate ($K_2HPO_4$) 0.5 g/l changed to 0.75 g/l, and ammonium sulfate ($(NH_4)_2SO_4$) 7 g/l changed to 0 g/l. Under these conditions, the final succinic acid concentration was 16.3 mM, which is about 1.46 fold higher than the original medium (11.1 mM) at 24 h. This work showed the improvement of succinate production by a simple change of media components deduced from sequential optimization.

• Korean Journal of Soil Science and Fertilizer
• /
• v.16 no.2
• /
• pp.162-167
• /
• 1983

These studies were carried out to investigate the effects of organic matter on the leaching of chemical constituents in paddy soil. Rice plants were cultured in paddy soil to which rice straw and compost were applied and then chemical properties of percolated water were analysed. The results were as follows: In the paddy soil cultured with rice plants, the pH value of soil was higher in the compost plot than in the rice straw plot. The leaching of iron, managanese, calcium, magnesium and phosphate was increased by cultivation of rice plant, but that of potassium, ammonium, and silica was decreased. When rice straw was applied in the paddy soil, the leaching of iron, managanese, phosphate and silica was increased during the growing periods, while that of calcium, magnesium, potassium and ammonium was increased by application of compost.

• Korean Journal of Microbiology
• /
• v.8 no.1
• /
• pp.41-51
• /
• 1970

In previous paper, it was reported that antibiotic substance such as tetracycline and streptomycin were produced by S'. albus subsp. and S'. globosus. And increase of mycelial growth of two strains, antibiotic production, and changes of pH range are extended to approximately 110-130 hrs in fermenting medium, there-after they decreased with culture period exception of pH range. Two Streptomyces spp. required commonly 4-5% starch as carbon sources and 1.5-2.0% soybean meal as nitrogen sources. However, 0.005-0.01M potassium phosphate dibasic, calcium carbonate (6mg/ml in S.albus subsp. and 2mg/ml in S. globosus), 0.01-0.03M, magnesium sulgate and 0.01M ferric chloride showed as optimal concentration for the growth of 2 strains. Mineral compoments such as zinc, manganese, cobalt, sodium and copper at the level of 10$^{-4}$ -10$^{-6}$ M were observed. Especially, zinc ion showed toxicity to the growth of 2 strains at 0.005M. In relation with pH, there is a little difference in mycelial growth with cultural initial pH.

• Korean Journal of Microbiology
• /
• v.13 no.1
• /
• pp.31-36
• /
• 1975

Chlorella ellipsoidea cells were cultured in a phosphate, magnesium, sulfur or potassium-free medium. Some portions of cells were taken out at intervals during the culture, and physiological activities such as growth rate, reproduction, photosynthetic activity, and biosynthesis of cholorophyll of macro-element deficient cells were measured. 1) Generally, growth rate, reproduction, photosynthetic activities, and biosynthesis of chlorophyll of the macro-element deficient cells decreased more or less, compared with those of the normal cells. 2) The growth and reproduction of the algal cells in sulfur, or magnesium free medium were retarted severely with the chlorosis ; the photosynthetic activity and the content of chlorophyll showed the same tendency. 3) It is considered that the decrease in growth rate of macro-element deficient Chlorella cells is due to the decrease in photosynthetic activity owing to the decrease in chlorophyll content of the cells.