• The Korean Journal of Mycology
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• v.25 no.3 s.82
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• pp.209-218
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• 1997

This study was carried out to obtain the basic data for artificial culture of Grifola umbellata. The optimal condition for the mycelial growth was obtained at $20^{\circ}C$ and pH 4, respectively. G. umbellata showed the most favorable growth on the Hoppkins media. Carbon sources such as glucose, fluctose and manitol were favorable for stimulating a mycelial growth of G. umbellata. Valine, one of nitrogen sources also appeared to be favorable to a mycelial growth. The optimum C/N ratio was about 30:1 in case that 1% glucose as carbon source was mixed with the basal media. Lactic acid as organic acid was most favorable to the mycelial growth. Also, thiamine-Hcl as vitamin source was favorable. The mineral nutrient of $FeSO_4$ or $MgSO_4$ was most favorable to G. umbellata, and its optimal concentration was about 0.01% in $FeSO_4$ and 0.1 % in $MgSO_4$ respectively. Among 4 different cereal extract media, polished rice extract medium which was mixed with silkworm pupae was most suitable for a favorable growth of G. umbellata.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.4
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• pp.554-566
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• 2018

The rice husk contains nutrients which can be easily utilized by microorganisms, and also has a water retaining ability, which played a crucial part in enabling it to become a biofilter media. In this study, we evaluated the applicability of rice husk pellet bio-scrubber as a microbiological carrier. The pelletization experiment of rice husk as a biological media was performed using PVA and EVA binder. Also, the feasibility tests of rice husk as a biological media for odor removal were carried out in order to know whether rice-husk contains useful components as a media for microbiological growth or not. Lastly, a combined test for odor gas absorption and biological oxidation was conducted using a lab scale bio-filter set-up packed with rice-husk pellets as wet-scrubber. The major components of the rice husk were carbon, hydrogen, nitrogen, and oxygen, while carbon acted as the main ingredient which comprised up to 23.00%. The C : N : P ratio was calculated as 45 : 1 : 2. Oxygen uptake rate, yield and decay rate of the rice husk eluent was calculated to be $0.0049mgO_2/L/sec$, 0.24 mgSS/mgCOD and 0.004 respectively. The most stable form of rice husk pellets was produced when the weight of the rice husk, EVAc, PVAc, and distilled water was 10 : 2 : 0.2 : 10. The prepared rice husk pellets had an apparent density of 368 g/L and a porosity of 59.00% upon filling. Dry rice husks showed high adsorption capacity for ammonia gas but low adsorption capacity for hydrogen sulfide. The bio-filter odor removal column filled with rice husk pellets showed more than 99.50% removal efficiency for NH3 and H2S gas. Through the analysis of circulation water, the prime removal mechanism is assumed to be the dissolution by water, microbial nitrification, and sulfation. Finally, it was confirmed that the microorganisms could survive well on the rice husk pellets, which provided them a stable supply of nutrients for their activity in this long-term experiment. This adequate supply of nutrients from the rice husk enabled high removal efficiency by the microorganisms.

• Journal of Mushroom
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• v.20 no.3
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• pp.168-172
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• 2022

This study was conducted to investigate the optimum supplementation ratio when replacing cotton seed meal with rapeseed meal for cultivating oyster mushrooms. The chemical properties among the treatments were pH 4.5~4.7, total carbon content was 46.3~46.5%, total nitrogen content was 1.6~1.7%, and carbon-nitrogen ratio was 27.0~27.8. These did not differ significantly from the control. Mycelial growth was 85.1 mm (Heuktari), and 72.8 mm (Suhan-1Ho) in medium containing 5% rapeseed meal, with no significant difference in mycelial density between cultivars. Fruiting body characteristics are as follows: In 'Heuktari', the color of the pileus was darker than control with an L value of 32.5, and pileus thickness and diameter were 3.2 mm and 27.6 mm, respectively. Stipe length and diameter were 86.0 mm and 9.1 mm, respectively. Valid stipe number per bottle (1,100 cc) was 25.9, and a yield of 189.7 g/1,100 cc was recorded in mixed medium containing 5% rapeseed meal (higher than control). In mixed medium containing 10% rapeseed meal, the yield was 184.5 g/1,100 cc (comparable to control). In 'Suhan-1Ho', supplemented with 5% rapeseed meal, pileus color was darker than control color, with an L value of 28.8. Pileus thickness was 4.5 mm. Stipe diameter was 12.3 mm (higher than control), and yield was 145.5 g/1,100 cc (comparable to control).

• Korean Journal of Environmental Biology
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• v.27 no.4
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• pp.384-390
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• 2009

An antifungal antibiotic-producing bacterium was isolated from soil and identified as Bacillus sp. CJ-1. The culture supernatant was found to have a strong and stable antifungal activity against Colletotrichum gloeosporioides. Culture conditions for the maximum antifungal activity were examined. Glucose and yeast extract were selected as the best carbon and nitrogen sources. The optimum C/N ratio was 3. The optimum temperature and initial pH were determined as $35^{\circ}C$ and 6.0, respectively. Under these conditions, the production for the antibiotic was maximized at 72 hr at $35^{\circ}C$ after cultivation. Microscopic observation showed that the culture supernatant of Bacillus sp. CJ-1 had a strong inhibitory activity on the mycelial growth of the test strain at above $12.5\;{\mu}L\;mL^{-1}$ of concentration.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.133-137
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• 2007

An experimental study is conducted to evaluate and compare the use of BiodieseDI Fuel supplements at blend ratio of 10/90(BDF10) and 20/80(BDF20), in four stroke, direct injection diesel engine located at the authors' laboratory. especially this Biodiesel is produced from Rape oil at the authors' laboratory. The tests are conducted using each of the above fuel blends, in the engine working at a speed of 1800rpm and at a various loads. In each test, specific fuel consumption, exhaust emissions such as nitrogen oxides(NOx), carbon monoxide(CO) and Soot are measured. The results of investigation at various operating conditions are as follows (1) Specific fuel consumption is increased average 1.52%, maximum 1.84% at load 25% in case of BDF10, and average 1.98%, maximum 2.80% at load 25% in case of BDF20. (2) CO emission is decreased average 5.14%, maximum 6.09% at load 0% in case of BDF10, and average 7.75%, maximum 9.13% at load 0% in case of BDF 20. (3) NOx emission is increased average 2.97%, maximum 3.74% at load 0% in case of BDF10, and average 3.84%, maximum 4.67% at load 0% in case of BDF20. (4) Soot emission is decreased average 9.36%, maximum 10.85% at load 75% in case of BDF10, and average 11.99%, maximum 13.95% at load 75% in case of BDF20.

• Journal of Life Science
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• v.12 no.2
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• pp.129-135
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• 2002

Several kinds of thermophilic, aerobic microorganisms (Bacillus genus), metal leaching microorganisms (Thiobacillus, T. ferooxidans), and other nondegradable chemical-degrading microorganisms (Pseudomonas genus) were utilized to study the effect on composting livestock manure. Under the Carbon-Nitrogen ratio (C/N) of 35∼40 and water content of 50∼65% conditions, the composting in the cycling drum reactor showed slower composting and lower temperature increase than that of the manual reactor. Element analysis after composting indicated relatively high levels of mineral contents with the substitutional effect of chemical fertilizer. Metal analysis before and after composting showed lower As in all, Cr in pig, Pb in cow, Hg in chicken, and Cu in cow manure compost than the regulation values. Compost maturity was ascertained by the several maturity tests. Salmonella and E. cozi detection test by SS or EMB agar plate confirmed the safety from the pathogenic microorganisms. The results suggest that the inoculation of metal and some other chemical degrading microorganisms during composting might decrease metal contamination and increase composting rate.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.451-455
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• 1992

In the medium containing 7% rice powder, 0.15% $NH_4NO_3$ and 0.1% $MnSO_4$ with initial pH 6.0, the red pigment production by Monascus anka albidus was observed. The mycelium were cultured at $30^{\circ}C$ for 5 days with reciprocal shaking (130 rpm). As a carbon source, glutinous rice gave the highest production of pigment. Ammonium nitrate and $KH_2PO_4$ as a nitrogen source and phosphate source, respectively, stimulated best the production of the red pigment. The optimum C:N ratio was found to be 18:1. The production of the pigment by the strain was 2.6 mg/ml in a flask, but 1.8 mg/ml in 5l fermentor, respectively.

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.947-953
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• 2011

A fungal strain, Aspergillus terreus strain GA2, isolated from an agricultural field cultivating sweet sorghum, produced feruloyl esterase using maize bran. In order to obtain maximum yields of feruloyl esterase, the solid state fermentation (SSF) conditions for enzyme production were standardized. Effective feruloyl esterase production was observed with maize bran as substrate followed by wheat bran, coconut husk, and rice husk among the tested agro-waste crop residues. Optimum particle size of 0.71-0.3 mm and moisture content of 80% favored enzyme production. Moreover, optimum feruloyl esterase production was observed at pH 6.0 and a temperature of $30^{\circ}C$. Supplementation of potato starch (0.6%) as the carbon source and casein (1%) as the nitrogen source favored enzyme production. Furthermore, the culture produced the enzyme after 7 days of incubation when the C:N ratio was 5. Optimization of the SSF conditions revealed that maximum enzyme activity (1,162 U/gds) was observed after 7 days in a production medium of 80% moisture content and pH 6.0 containing 16 g maize bran [25% (w/v)] of particle size of 0.71-0.3 mm, 0.6% potato starch, 3.0% casein, and 64 ml of formulated basal salt solution. Overall, the enzyme production was enhanced by 3.2-fold as compared with un-optimized conditions.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.84-88
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• 2001

About 100 bacterial strains producing proteolytic enzymes were isolated from Korean traditional soy paste Doenjang. Among them, strain SYG3 producing the highest level of angiotensin converting enzyme (ACE) inhibitor into the culture medium was selected and identified as Bacillus pumilus according to the Bergey's mannual of systematic bacteriology. Soybean powder as a nitrogen source and glucose as a carbon source supported high level of ACE inhibitor production. The presence of 3% NaCl also enhanced the production of ACE inhibitor in the medium. The optimum initial pH of the medium and culture temperature for the production of ACE inhibitor were 7.0 and $32^{\circ}C$, respectively. The maximal level of ACE inhibitory effect was obtained after 36 hours of cultivation under the optimized conditions, which was about 98% of inhibition ratio.

• Korean Journal of Environmental Biology
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• v.22
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• pp.93-102
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• 2004

A total of 110 surface sediment were analyzed in order to understand the geochemical eharacteristics of the surface sediments and to evaluate the benthic environmental condition of Gwangyang Bay. The surface sedimentary distribution can be classified by five facies; mud (M), sandy mud (sM), sand (S), muddy sand (mS) and gravely sand mud ((g)sM). However, mud face is the predominant sedimentary feature of the Gwangyang Bay. The benthic environment based on total organic carbon/total nitrogen (C/N) and total organic carbon/total sulfur (C/S) ratios of organic matter showed that anoxic environment is prevailed in some parts of the study area because the C/S ratio of organic matter was higher than 2.8. The hydrogen sulfide (H$_2$S) content showed extreme variability from site to site. It varies from 307 ppm to 1 ppm (average, 92 ppm). The inter-relationship of redox-sensitive elements (Mn, V, Mo and Cr) showed a relatively strong positive relationship with high accumulation in the sediment at the inner sites of the Bay (left of Myo Island). High content of TOC and hydrogen sulfide, and a high accumulation rate of redox- sensitive element were predominant characteristics in the sediments at the inner sites of the Bay (left of Myo Island), suggesting that this area is in an oxygen deficient, and potentially polluted condition.