• Microbiology and Biotechnology Letters
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• v.11 no.3
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• pp.217-222
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• 1983

By the treatment of Gibberella fujkuroi I-892 with mutagen such as UV light and N-methyl-N'-nitro-N-nitrosoguanidine, a mutant G. fujkuroi G-471 was selected as the highest producer of gibberellic acid among 800 mutant strains. It showed 30% increase of production yield compared with that of the parent strain. At optimum medium composition (saccharose 1.0%, ammonium tartarate 50mM, malt extract 1.0% KH$_2$PO$_4$ 0.5%, MgSO$_4$0.5%, FeSO$_4$0.0002%, trace element sol.0.002% (v/v), the yield of submerged culture increased by 30% after 7 days culture at 24$^{\circ}C$ (253mg/$\ell$). In submerged culture, the initial pH showed much effects on the increase of gibberellic acid production. The highest yield of the production was attained with pH adjustment to 4.0 at the initial stage of fermention.

• Korean Journal of Microbiology
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• v.12 no.1
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• pp.31-36
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• 1974

Four strains of yeasts were chosen from those isolated previously, and a strain from 160 isolates collected in this year were examined for the treatment of pulp waste liquor. Experiments about optimum nutrient condition, composition of cells, and reduction of B.O.D. on the "S" pulp industry waste liquor were performed with 5 strains. 1. The isolates(strain 112) was identified as Candida utilis. 2. The optium concentration of 4 components of nutrients were ($NH_4$)$SO_2$lg/l, yeast extract 70mg/l, $KH_2PO_4$ 300mg/l, and $MgSO_4{\ddot}7H_2O$ 500mg/l. 3. Specific growth ratio of Candida utilis KYRI 112 was 0.48/hr at optimum nutrient media and the yield was 0.45%(V/V). 4. Endomycopsis capsularis KYRI 613 contained more crude protein than the most of commercial yeasts. 5. The B.O.D. of waste liquor was reduced ro 20% of its value by the culture.e culture.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.622-628
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• 1998

Microorganisms isolated from soil were tested for their flocculating activity in kaolin suspension, Identification of the best producing CH-23 strain showed that the strain belonged to the Bacillus megaterium. The maximum production of the flocculating from Bacillus megaterium CH-23 was observed in the culture medium containing 2% sucrose, 3% NaNo3, 0.1% K2HPO4, 0.5% NaCl, 0.5% MgSO4.7H2O and 0.01% tryptone at initial pH 7.0 and 25~3$0^{\circ}C$. Flocculating activity was improved to 57% when the culture medium contained Mn2+(0.01% MnSo4). In the culture medium containing Mg2+(0.01% MgSO4.7H2O) and Ca2+(0.01% CaCO3), flocculating activity were reached to 48% and 33%, respectively.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.268-273
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• 1998

Changes of chemical component and losses of chemical fertilizer by infiltration water from 0.5ha of paddy field in Chinan area of Chonbuk province during the rice cultivation were investigated. The infiltration water samples were collected in a ceramic porous cup which was a buried at the 30, 50, 70, 90㎝ of soil depth. pH of infiltration water ranged $6.64{\sim}7.90$ and EC showed $324{\sim}647{\mu}$S/cm. The content of total-N, $NH_4-N$ and $NO_3-N$ were $0.58{\sim}14.59$, $0.05{\sim}4.25$, and $0.15{\sim}7.71mg/L$ respectively. The content of total-P and ortho-P were $0.009{\sim}0.077mg/L$ and $0{\sim}0.029mg/L$ The content of $Ca^{++}$, $Mg^{++}$, $Na^{+}$ and $K^{+}$ showed $0.88{\sim}4.78$, $0.22{\sim}1.04$, $0.17{\sim}0.98$, and $0.84{\sim}3.19㎎/L$. These all at the first transplanting are higher than that of other periods. The content of $SO_4^{2-}$ showed $3.92{\sim}18.72mg/L$ and decreased with a soil depth. However $Cl^-$ of infiltration water ranged $9.03{\sim}19.97mg/L$ and no difference with a soil depth. When infiltrated $2,416.5m^{3}$ of an infiltration water from 0.5ha of paddy field during the rice cultivation, losses of chemical components were 20.34㎏/㏊ of total-N, 3.54㎏/㏊ of $NH_4-N$, 10.44㎏/㏊ of $NO_3-N$, 0.16㎏/㏊ of total-P and 0.028㎏/㏊ of ortho-P. Also $Ca^{++}$, $Mg^{++}$, $Na^+$, $K^+$, $SO_4^{2-}$ and $Cl^-$ were lost 10.24, 2.84, 2.84, 7.22, 50.04 and 62.20㎏/㏊ respectively. There were lost by infiltration water 9.35% of nitrogen, 0.59% of phosphorous and 22.79% of potassium in applied chemical fertilizer.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.1
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• pp.109-116
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• 2017

This paper describes the investigation into the durability alkali-activated materials(AAM) mortar and paste samples manufactured using fly-ash(FA) and ground granulated blast furnace slag(GGBFS) exposed to a sulfate environment with different GGBFS replace ratios(30, 50 and 100%), sodium silicate modules($Ms[SiO_2/Na_2O]$ 1.0, 1.5 and 2.0). The tests involved immersions into 10% sodium sulfate solution($Na_2SO_4$), 10% magnesium sulfate solution($MgSO_4$), 10% magnesium nitrate solution($Mg(NO_3)_2$) and 5% magnesium nitrate($Mg(NO_3)_2$+5% sodium sulfate solution+$Na_2SO_4$). The evolution of compressive strength, weight, length expansion and microstructural observation such as x-ray diffraction were studied. As a results, in case of immersed in $Na_2SO_4$, $Mg(NO_3)_2$ and $Mg(NO_3)_2+Na_2SO_4$ shows increase in long-term strength. However, for samples immersed in $MgSO_4$, the general observation was that the compressive strength decreased after immersion. The most drastic reduction of compressive strength and expansion of weight and length occurred when GGBFS or Ms ratios were higher. Also, the XRD analysis of samples immersed in magnesium sulfate indicated that expansion of AAM caused by gypsum($CaSO_4{\cdot}2H_2O$) and brucite(MgOH). The results showed that, an additional condition $Mg^{2+}$ in which ${SO_4}^{2-}$ is the presence of a certain concentration, sulfate erosion has to be accelerated.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.5
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• pp.794-798
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• 1999

An experiment was conducted to determine the effects of supernormal level of copper (Cu) from different supplementary sources on the performance, cholesterol level in plasma and breast muscle, and accumulation of fat and Cu in broilers. In a 5 wk feeding trial, two hundred forty hatched male broiler chickens were assigned to four dietary treatments: control diet containing 10 mg/kg supplementary Cu, control diet plus 250 mg/kg Cu from $CuSO_4$ ($CuSO_4-250$), control diet plus 125 mg/kg Cu from Cu-methionine chelate (Cu-Met-125), and control diet plus 250 mg/kg Cu from Cu-methionine chelate (Cu-Met-250). Weight gain in Cu-Met-125 treatment and Cu-Met-250 treatment were not different, but they were significantly (p<0.05) greater than that in $CuSO_4-250$ treatment. Plasma total cholesterol and reduced glutathione (GSH) in blood were significantly reduced by supplementation of $CuSO_4-250$, but were not significantly affected by Cu-Met supplementations. Plasma HDL cholesterol, plasma triglycerides and breast muscle cholesterol were not significantly affected by Cu supplementation. $CuSO_4-250$ improved metabolizability of crude fat, which resulted in low abdominal fat pad weight. Cu from Cu-Met was better absorbed and accumulated more in the breast muscle and lesser in the liver compared with Cu from $CuSO_4$.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.66-70
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• 2005

This study was conducted to determine the effects of MgSO₄ supplement on meat quality and serum stress hormones concentrations in late finishing pigs. Sixty castrated Landrace pigs (average weight±S.D., 106.5±8.9 kg) were assigned to a control diet (without MgSO₄ supplement) and diet with MgSO₄(10 g/kg diet) supplemented. Pigs had free access to diets and water during five-day feeding period. At the end of feeding experiment, pigs were fasted for 16 hours and transported to commercial slaughter plant (30-minute transportation distance). After 2-hour lairage time, pigs were slaughtered, and blood samples were collected at bleeding procedure of slaughter. Pigs fed the diet with MgSO₄ supplement had higher (p<0.05) serum magnesium concentrations than those in pigs fed a control diet. Serum adrenaline, noradrenaline and cortisol concentrations determined at slaughter were not significantly different between dietary groups. Carcass temperature, pH at 24h post- slaughter, drip loss and color characteristics were not influenced (p>0.05) by short-term supplement of MgSO₄. Pigs fed the diet supplemented with MgSO₄ diet had lower PSE incidence (23.3%) compared to pigs fed the control diet (33%). These results indicate that short-term supplement of dietary MgSO₄ in late finishing pigs may not be beneficial in improving pork quality, and further study needs to assess feeding regime of magnesium supplement.

• Journal of the Mineralogical Society of Korea
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• v.30 no.4
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• pp.205-217
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• 2017

Mineral carbonation by indirect method has been studied by serpentinite as cation source. Through the carbonation of $CO_2$ and alkaline earth ions (calcium and magnesium) from serpentinite, the pure carbonates including $MgCO_3$ and $CaCO_3$ were synthesized. The extraction solvent used to extract magnesium (Mg) was ammonium sulfate ($(NH_4)_2SO_4$), and the investigated experimental factors were the concentration of $(NH_4)_2SO_4$, reaction temperature, and ratio of serpentinite to the extraction solvent. From this study, the Mg extraction efficiency of approximately 80 wt% was obtained under the conditions of 2 M $(NH_4)_2SO_4$, $300^{\circ}C$, and a ratio of 5 g of serpentinite/75 mL of extraction solvent. The Mg extraction efficiency was proportional to the concentration and reaction temperature. $NH_3$ produced from the Mg extraction of serpentinite was used as a pH swing agent for carbonation to increase the pH value. About 1.78 M of $NH_3$ as the form of $NH_4{^+}$ was recovered after Mg extraction from serpentinite. And, the main step in Mg extraction process of serpentinite was estimated by geochemical modeling.

• KSBB Journal
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• v.14 no.2
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• pp.167-173
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• 1999

A new synthetic medium was developed for the submerged mycelial cultures of Phellinus linteus. The medium for maximum mycelial growth of Phellinus linteus (3 days incubation, 28$^{\circ}C$, pH 5) consisted of (per 1 L): glucose, 90 g peptone, 10 g soluble starch, 10 g yeast extract, 3 g KH2PO4, 1 g MgSO4.7H2O, 1 g and CaCl2, 0.1 g. The concentrations of glucose, peptone, yeast extract, KH2PO4, MgSO4.7H2O, and CaCl2 were examined in the ranges of 10~90 g/L, 0~10 g/L, 0~15 g/L, 0~2 g/L, 0~1 g/L, and 0~0.5 g/L, respectively. The dry weight of mycelium in 3 days increased to 16.79 mg/mL using the new synthetic medium. The optimum temperature for mycelial growth of Phellinus linteus was 28$^{\circ}C$. The concentrations of KH2OP4, CaCl2, and yeast extract, which gave the maximum mycelial growth of Phellinus linteus, existed in the concentration ranges examined in this study. But, in the cases of other compositions (MgSO4.7H2O, peptone, and glucose), the mycelial growth of Phellinus linteus increased with the concentration in the ranges.

• KSBB Journal
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• v.14 no.4
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• pp.440-444
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• 1999

For the effecient production of clavulanic acid., a mutant strain Streptomyces clavuligerus KK was selected from Streptomyces clavuligerus ATCC 27064 through mutation with NTG. S. clavuligerus ATCC 27064 produced about 200 mg/L of calvulanic acid when the medium was composed of 1%(W/V) glycerol, 1.5%(W/V) soybean flour, 0.1%(W/V) $KH_2PO_4$, 0.2%(V/V) soybean oil. A selected mutant, S. clavuligerus KK, produced about 1150 mg/L of clavulanic acid in the same medium. After the addition of $MgSO_4$ to the basal medium, S. clavuligerus KK produced about 1550 mg/L of clavulanic acid, with shows about 1.3 times higher than that produced in the basal medium. In order to select the proper bioreactor for the production of clavulanic acid, a batch culture was performed in an airlift, a bubble column and an stirred tank bioreactors. In an airlift bioreactor, about 1350 mg/L of clavulanic acid was produced, in a bubble column bioreactor, about 1550 mg/L, in a stirred tank bioreactor, about 2200 mg/L, respectively. The production of clavulanic acid in stirred tank bioreactor was about 50% higer than that by an airlift and a bubble column bioreactors. According to this result, the stirred tank bioreactor was selected as a proper bioreactor.