• Korean Journal of Ecology and Environment
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• v.41 no.spc
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• pp.21-26
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• 2008

The in situ incubation experiment was carried out using $^{13}C$ tracer to determine primary productivity and fatty acid production rate in the shallow, eutrophic Shingu reservoir on 4th July. Particulate organic matter (POM) accounted for 76% in suspended particulate matter (SPM), and average concentration of chlorophyll-${\alpha}$ was $89{\mu}g\;L^{-1}$ in the euphotic layer. Total amount of chlorophyll-${\alpha}$ (Chl-${alpha}$), primary productivity and Chl-${alpha}$ specific productivity in euphotic layer were 112 mg Chl-${alpha}m^{-2}$, 3.53 g C $m^{-2}\;d^{-1}$, 32mg C mg Chl-${\alpha}^{-1}\;d^{-1}$, respectively. The fatty acid composition in newly produced organic matter and suspended organic matter didn't show any significant difference, demonstrating that autochthonous organic matter should be a major source of POM pool. In addition, the fatty acids of bacterial origin were increased through extracellular release of newly photosynthesized DOC, and closely coupled with bacterial assimilation. This result suggests that organic carbon should be actively cycled through the microbial loop in Shingu reservoir in summer.

• Korean Journal of Agricultural Science
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• v.48 no.1
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• pp.45-57
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• 2021

This study aimed to determine the effects if ambient temperature (Ta), relative humidity (RH), and temperature-humidity index (THI) on milk production parameters such as milk yield, fat, protein, milk urea nitrogen (MUN), and lactose. A total of fifty (50) mid-lactating Korean Holstein cows (144 - 150 days postpartum) were randomly assigned to two groups in equal numbers (n = 25) according to the type of diet received: conventional feed, a mixture of 56: 44 ratio of roughage and concentrate mix, and organic feed containing 100% organic roughage. Temperature, RH, and THI were recorded daily and averaged monthly. Conventional group showed higher dry matter intake throughout the experiment and thus, showed higher total milk yield and milk composition such as milk fat, protein, and lactose content than organic milk. Milk of the conventional group showed higher polyunsaturated fatty acid concentration. Highest milk yield was observed in September (21.7℃, 82.4%RH) in conventional group (27.69 kg·day^-1) and in June (21.4℃, 72.9%RH) in organic group (14.31 kg·day^-1). In conventional group, milk yield was positively correlated with Ta and THI, and milk protein was negatively correlated with Ta, RH, and THI. In organic feeding, only the MUN among milk composition parameters showed a significant correlation where it showed a negative correlation with Ta, RH, and THI. Conventional feeding showed significantly higher milk yield, fat, protein, and lactose than organic feeding throughout the experiment, although, organic feeding showed to be less likely affected by Ta, RH, and THI than the conventional feeding.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.2
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• pp.188-199
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• 2015

Nineteen tanniferous browse plants were collected from South Africa to investigate their digestibility, gas production (GP) characteristics and methane production. Fresh samples were collected, dried in forced oven, and ground and analyzed for nutrient composition. In vitro GP and in vitro organic matter digestibility (IVOMD) were determined using rumen fluid collected, strained and anaerobically prepared. A semi-automated system was used to measure GP by incubating the sample in a shaking incubator at $39^{\circ}C$. There was significant (p<0.05) variation in chemical composition of studied browses. Crude protein (CP) content of the species ranged from 86.9 to 305.0 g/kg dry matter (DM). The neutral detergent fiber (NDF) ranged from 292.8 to 517.5 g/kg DM while acid detergent fiber (ADF) ranged from 273.3 to 495.1 g/kg DM. The ash, ether extract, non-fibrous carbohydrate, neutral detergent insoluble nitrogen, and acid detergent insoluble nitrogen and CP were negatively correlated with methane production. Methane production was positively correlated with NDF, ADF, cellulose and hemi-cellulose. Tannin decreased GP, IVOMD, total volatile fatty acid and methane production. The observed low methanogenic potential and substantial ammonia generation of some of the browses might be potentially useful as rumen manipulating agents. However, a systematic evaluation is needed to determine optimum levels of supplementation in a mixed diet in order to attain a maximal depressing effect on enteric $CH_4$ production with a minimal detrimental effect on rumen fermentation of poor quality roughage based diet.

• International Journal of Highway Engineering
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• v.7 no.3 s.25
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• pp.53-62
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• 2005

Efficient snow-removing work is one of important processes of winter road management. Calcium chloride has been used as a typical deicing agent in Korea. It presents superial performance as snow deicing agents, however it has been known to give serious environmental problem and to deteriorate durability of concrete structure in road by corrosion. The environment-friendly road deicing agents made from the waste material which is liquid phase organic matter that is Ca Mg and reactant of organic acid (nitric acid and propionic acid) have been introduced by number of researchers. They indicated the calcium magnesium salt of organic acids have advantage over the calcium choride in terms of lower production unit cost by resources recycling and can solve environmental problem and durability deterioration of structures. In this study, the deicing performance of calcium magnesium salt of organic acids(CMO) is investigated based on the series of experiments including the test for heat of dissolution, freezing point, ice melting test and ice penetration test.

• KSBB Journal
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• v.22 no.4
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• pp.201-206
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• 2007

The demand of L-arabinose has been increased recently because of its advantages including clinical effect. L-arabinose can be produced from dilute acid hydrolysis of agricultural wastes. In this study, optimum conditions of L-arabinose production using dilute acid hydrolysis of agricultural wastes and nutshells were determined. Among the tested various agricultural wastes and nutshells, corn fiber was selected as the best raw material for the production of arabinose. The highest arabinose production was achieved an acid hydrolysis of corn fiber for 1 h at 130$^{\circ}C$ with 0.4% sulfuric acid. Above optimal conditions, it was obtained 20.1 g/L glucose, 10.1 g/L xylose, 7.8 g/L arabinose and 1.8 g/L galactose from 90 g/L of corn fiber. For the purification of arabinose, it was carried out to remove all of sugars except arabinose by the Candida tropicalis cultivation of acid hydrolyzate and an organic contaminants such as pigments by the active carbon treatment of fermentation broth. Moreover, experiments were carried out to eliminate an ions by exchange chromatography. Finally, we obtained 3.1 g of partially purified L-arabinose powder with about 40% yield by evaporation and vacuum drying.

• KCID journal
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• v.18 no.2
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• pp.25-32
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• 2011

The 21 livestock farms considering future installation of biogas systems were studied. These farms were examined how to raise the livestock, to treat manure, to operate facility with respect to manure characteristics. The 15 farms out of 21 farms have applied to the marine dumping and consignment treatment for treating manure and even farms which have equipped liquid fertilizing system have less capacity facility than legal standards. Characteristics of manure were affected by the scale of swine barn, clean water usage, frequency of cleaning, cleaning method, feces-urine separating method, etc. Retention time in storage (over 20 days) has resulted in lower concentration of organic matter which could reduce biogas production. This indicates that systematic barn management system is required. Inhibition tests showed that disinfectant and citric acid did not affected digestion rates at 10 times higher concentration than recommendation. However hypochlorous acid is likely to affect the anaerobic microbial activity.

• The Korean Journal of Food And Nutrition
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• v.7 no.1
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• pp.51-57
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• 1994

A nuluk, a Korean traditional koji for brewing, was made with wheat flour and Aspergillus usamii mot. shirousamii S1 which had strong abilities in producing amylase and protease. The cultural conditions for the production of saccharogenic and proteolytic enzymes were tested. The productivities of saccharogenic and dextrogenic enzymes were improved when nuluk was made with unsteamed wheat flour as compared with steamed one, but those of proteolytic enzyme and organic acid were reduced. The addition of water containing 0.5% of hydrochloric acid was unfavorable for the production of saccharogenic, dextrogenic and proteolytic enzymes. The optimum ratios of water added to wheat flour for the production of saccharogenic enzyme and proteolytic enzyme were 32% and 28%, respectively on the basis of wheat flour. The optimum temperatures for the production of saccharogenic enzyme and proteolytic enzyme were 36$^{\circ}C$ and 28$^{\circ}C$, respectively. The activity of saccharogenic enzyme reached its maximum after 120 hours of cultivation at 36$^{\circ}C$, but that of proteolytic enzyme 96 hours. The productivity of saccharogenic enzyme was enhanced when the nuluk was molded after 24 hours of precultivation but that of proteolytic enzyme was reduced as compared with no molding.

• Journal of Microbiology and Biotechnology
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• v.13 no.2
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• pp.256-262
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• 2003

To enhance the production of heavy chain immunoglobulin G (HC IgG) in the suspension cultures of transgenic tobacco cells (Nicotiana tabacum), the effects of adding various cytokinins (i.e., growth regulators) and organic nitrogen sources to culture media were investigated. Four different cytokinins including kinetin, isopentenyladenine (IPA), 6-benzylaminepurine (BA), and zeatin were tested with or without dichlorophenoxyacetic acid (2,4-D), which is a typical growth regulator supplemented in the standard Murashige and Skoog (MS) medium. The productivity of intracellular HC IgG was increased by 36 and $42\%$, compared to the control, especially when IPA (2 mg/l) or BA (0.2 mg/l) was added to the media in the presence of 2,4-D, respectively. In the study of organic nitrogen sources, addition of each casein hydrolysate and tryptone to the culture media at a final concentration of 0.01 and 1 g/l, respectively. increased the productivity or he IgG as much as 68 and $67\%$, respectively, in comparison with the control, which was is MS medium without supplementation of any organic nitrogen sources. This study shows that the optimization of media composition could offer significant improvements in the production of foreign proteins in the suspension cultures of transgenic plants.

• Journal of Environmental Science International
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• v.31 no.12
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• pp.1127-1134
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• 2022

Herein , the effect of changes in the organic loading rate in anaerobic digestion was evaluated. The experiment was carried out by a laboratory -scale semi-continuous stirred tank reactor, and feedstock was food-waste leached. The organic loading rate was increased by 0.5 kgVS/m3 in each phase from 1.0 kgVS/m3 to 4.0 kgVS/m3. At the end of the operation, to check the failure of the reactor, the organic loading rate was increased by 1.0 kgVS/m3 in each phase and reached 6.0 kgVS/m3. This shows that the biogas yield decreased as organic loading rate increased. Biogas production seemed to be unstable at 3.5-6.0 kgVS/m3. Moreover, biogas production dramatically fell to approximately 0 mL at 6.0 kgVS/m3, which was decided as the operation failure on the 16th day of the las tphase. The result of the reactor analysis shows that the cumulation of volatile fatty acid increased as the organic loading rate increased. This seems to occur due to the decreasein pH in the reactor and led to extinction of anaerobic bacteria, which were the biogas products. Although the buffer compound (alkalinity) could prevent the decline in pH, the concentration of alkalinity was found to be lacking at a high organic loading rate

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.856-864
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• 2019

Objective: The objective of this study was to investigate effects of mixed organic acids (MOA) on nutrient digestibility, volatile fatty acids composition and intestinal microbiota in growing-finishing pigs fed high wheat bran diet. Methods: Six crossbred barrows ($Duroc{\times}Landrace{\times}Yorkshire$), with an average body weight $78.8{\pm}4.21kg$, fitted with T-cannulas at the distal ileum, were allotted to a double $3{\times}3$ Latin square design with 3 periods and 3 diets. Each period consisted of a 5-d adjustment period followed by a 2-d total collection of feces and then a 2-d collection of ileal digesta. The dietary treatments included a corn-soybean-wheat bran basal diet (CTR), mixed organic acid 1 diet (MOA1; CTR+3,000 mg/kg OA1), mixed organic acid 2 diet (MOA2; CTR+2,000 mg/kg OA2). Results: Pigs fed MOA (MOA1 or MOA2) showed improved (p<0.05) apparent total tract digestibility (ATTD) of gross energy, dry matter and organic matter, and pigs fed MOA2 had increased (p<0.05) ATTD of neutral detergent fiber compared to CTR. Dietary MOA supplementation decreased (p<0.05) pH value, and improved (p<0.01) concentrations of lactic acid and total volatile fatty acids (TVFA) in ileum compared to CTR. Pigs fed MOA showed higher (p<0.05) concentration of acetic acid, and lower (p<0.05) content of formic acid in feces compared to CTR. Pigs fed MOA1 had increased (p<0.05) concentration of TVFA and butyric acid in feces. Pigs fed MOA1 showed higher concentration of Lactobacillus and lower concentration of Escherichia in feces compared to CTR. Conclusion: Dietary supplementation of MOA 1 or 2 could improve nutrients digestibility, TVFA concentration and intestinal flora in growing-finishing pigs fed high fiber diet.