• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.788-794
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• 2009

Both strains of KD-1212 and DAH-1056 were isolated and identified from animal manure-contaminated soil by screening bacterial strains for the removal of sulfur compound-malodor with such substrate as sodium thiosulfate or free sulfur. Then the characteristics on the incubation of these microbes were observed under various incubating-condition such as pH, temperature, aerobic or anaerobic, substrate(sulfur compound) concentration, nitrogen and carbon source and rotating speed for mixing, and the optimum incubating condition was established. The optimum pHs of KD-1212 and DAH-1056 were 7.0 and 4.0, respectively, and their optimum temperatures were in the range of $30{\sim}35^{\circ}C$. Another autotrophic strain, ED-1138, was isolated from contaminated soil. The strain DAH-1056 excelled a strain Thiobacillus sp. IW in eliminating hydrogen sulfide during the process of malodor-biofiltration with a fixed strain. The characteristics on the incubation of strain KD-1212 were observed under various substrate-concentrations, nitrogen and carbon sources. KD-1212 favored glucose and maltose, and yeast extract as carbon sources and nitrogen source, respectively. The optimum concentrations of substrate and nitrogen source were 25 mM of sodium thiosulfate and 0.5% yeast extract, respectively for the growth of strain KD-1212.

• Journal of Animal Science and Technology
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• v.62 no.1
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• pp.52-57
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• 2020

In rumen in vitro experiments, although nitrogen gas (N₂) flushing has been widely used, its effects on rumen fermentation characteristics are not clearly determined. The present study is the first to evaluate the effects of N₂ flushing on rumen fermentation characteristics in in vitro batch culture system by comparing with new applicable non-metabolizable gas: argon (Ar). The rumen fluid was taken from two Korean native heifers followed by incubation for 3, 9, 12, and 24 h with N₂ or Ar flushing. As a result, in all incubation time, N₂ flushing resulted in higher total gas production than Ar flushing (p < 0.01). Additionally, in N₂ flushing group, ammonia nitrogen was increased (p < 0.01). However, volatile fatty acids profiles and pH were not affected by the flushing gases (p > 0.05). In conclusion, the present study demonstrated that N₂ flushing can influence the rumen nitrogen metabolism via increased ammonia nitrogen concentration and Ar flushing can be used as a new alternative flushing gas.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.355-372
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• 2004

In vitro experiments were conducted to determine the formation of fatty acid soaps (FAS) and neutral detergent fiber (NDF) disappearance rate. The substrates were a basal alfalfa hay containing 1) no oil, 2) 10% soybean oil, 3) 10% com oil, on a weight basis. All the substrates were incubated in triplicate for 0, 3, 6, 12, 24 and 48h in each experiment. After the incubation in the first experiment serum bottles (6oml) were analyzed for nonesterified, esterifed and fatty acid soaps contents. The serum bottles (120mI) from the second experiment were analyzed for pH, $NH_3-N$ and VFA concentration, and dry matter and NDF disappearance rate. pH decreased and the concentration of NH3-N increased significantly with longer incubation time (P<0.0001). The disappearance rates of dry matter and NDF significantly varied with feed, incubation time and oils (P<0.05). The molar concentration of total VFA increased and proportion of acetate significantly decreased with incubation time (P<0.0001), but the proportion of propionate significantly increased with longer incubation time (P<0.0001). Addition of oils to diet lowered the ratio of acetate:propionate (P<0.05). The esterified fatty acids (EFA) decreased with increasing incubation time (P<0.0001), and nonesterified fatty acids (NEFA) increased due to lipolysis of EFA, NEFA then reacted with cations to increase formation of FAS. The formation of FAS increased significantly at 48h of incubation time (P<0.0001). Especially, formation of stearic acid soaps was 27.5 and 32.5 folds with soybean oil and com oil supplements, respectively, by 48h of incubation time (P<0.0001). Alfalfa hay had higher cation contents, particularly Ca, which react with NEFA and FAS can be formed with longer incubation time. Saturated fatty acids had a higher proportion of FAS than did unsaturated fatty acids, suggesting that the former may react more extensively with cations. FAS contents increased with increasing chain length of the fatty acids. Since added vegetable oils fonned FAS, it might decrease negative effects on in vitro fermentation characteristics and NDF disappearance rate.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.987-996
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• 2003

This study was conducted to determine the effects of the artificial culture medium of wild-ginsengs on in vitro fermentation characteristics. NH$_3$-N concentration was showed the highest in 3% WGM treatment among all treatments and control. In addition, microbial protein synthesis was significantly different in all treatments throughout the incubation time, and WGM 3% treatment was the highest at the 9 h incubation(P〈0.05). Protozoa numbers within rumen were decreased in all WGM treatments at 9 h incubation time, whereas WGM 3% treatment was always decreased throughout the incubation(P〈0.05). NDF and ADF digestibility were proportionally increased as the incubation time in both control and treatments. NDF digestibility showed no significantly difference between control and the 3% treatment, and ADF digestibility was similar in all. Total volatile fatty acid(VFA) concentrations of WGM treatments without 5% were significantly higher than control (P〈0.05). No differences were observed in total VFA, acetate, propionate and butyrate concentration among the WGM treatments. Acetate/Propionate ratio of WGM treatments was higher than control after 12 h incubation(P〈0.05). As a result of the artificial culture medium of wild-ginseng on rumen fermentation characteristics in vitro, microbial protein synthesis of WGM treatment was higher than control, and WGM 3% was the highest in all treatments(P〈0.05). The effect of saponin in artificial culture medium of wild-ginseng tended to decrease NH$_3$-N concentration, while it increases the microbial synthesis in early incubation. Therefore, artificial cultures medium of wild-ginseng can increase utilization of feed by microbial and anti-protozoal effects of saponin, which may enhance microbial synthesis capacity in early fermentation period in rumen.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.1
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• pp.49-60
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• 2008

A study was conducted to determine the effect of alcohol-fermented feedstuff formulated with byproducts on the fermentation characteristics and dry matter disappearance in the rumen. Dietary treatments were either a soybean curd-based alcohol-fermented feedstuff(AFS) and brewery grain-based alcohol-fermented feedstuff(AFB). The AFS and AFB are composed of 50% commercial beef cattle feed, 50% soybean curd dreg, 5% molasses and 0.5% yeast, and 25% commercial beef cattle feed, 25% brewery grain, 25% soybean curd dreg, 25% corn grit, 5% molasses and 0.5% yeast, respectively. The ruminally cannualted Korean cattle were utilized to investigate the change of ammonia, pH alcohol, volatile fatty acids, and DM digestibility at 0, 2, 4, 8 and 12 hr after feeding. The rumen ammonia concentrations were significantly lower in AFS and AFB with incubation time, especially at 6 hr incubation(AFS, 0.7 mg/dl; AFB, 1.5 mg/dl; control 2.5 mg/dl). Lower rumen pH was observed in AFS and AFB during the early stage of incubation, but no significant difference was found at late stage of incubation. The total VFA concentrations were not affected by diet treatments at 2 hr incubation time, but the concentration significantly decreased after that. The dry matter disappearance was significantly lower in AFS and AFB during the early stage of incubation. However, the dry matter disappearance of AFS and AFB was similar to that of control during the late stage of incubation. It is concluded that the industrial byproducts such as soybean curd dreg and brewery grain were effective materials to make an alcohol fermented feedstuffs and resulted in better fermentation characteristics in the rumen when both were applied to Hanwoo.

• Korean Journal of Agricultural Science
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• v.43 no.1
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• pp.80-86
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• 2016

An in vitro trial was conducted to examine the effects of total mixed rations (TMR) on fermentation characteristics and effective degradability (ED) by rumen microbes. Three TMR diets were growing period TMR (GR-TMR, 67% TDN), early fattening period TMR (EF-TMR, 75.4% TDN) and late fattening TMR (LF-TMR, 80% TDN). Three TMR diets (3 g of TMRs in each incubation bottles) was added to the mixed culture solution of stained rumen fluid with artificial saliva (1:1, v/v) and incubated anaerobically for 48 hours at $39^{\circ}C$. The pH in all incubation solutions tended to decrease up to 48h, but the opposite results were found in concentration of total gas production, ammonia-N and total VFA in all incubations.The total gas production (p<0.05) in LF-TMR was highest compared with those of other diets. Also, concentration of total VFA was tended to increase in LF-TMR compared with other TMR diets in all incubations. The EDDM in both EF-TMR and LF-TMR was tended to high compared with GR-TMR (p=0.100). In this in vitro trials, concentration of propionate in all incubation solution was not affected by increased concentration of TDN. The results of the present in vitro study indicate that TMR may provide more favorable condition for nutrient digestion both in the rumen.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.976-985
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• 2010

In this study, characteristics of dissolved organic matter (DOM) from Lake Paldang and seven other DOM sources (lake plankton, plants, soil, composite, treated sewage) were studied using XAD resin fractionation and 28-day microbial incubation experiment. Distribution patterns of DOM-fractions, which include hydrophilic acids (HiA), hydrophilic bases (HiB), hydrophilic neutrals (HiN), hydrophobic acids (HoA), hydrophobic neutrals (HoN) and the extent of DOM biodegradation (i.e., biodegradability) were different depending on the origins of the DOM samples. The DOM distribution pattern and the biodegradability were found to be effective for distinguishing the different DOM sources. The biodegradability (%) had negative correlations with the content (%) of hydrophobic fractions (Ho) and specific UV absorbance of DOM, which indicate that the Ho fractions contain more aromatic carbon structures and relatively stable during biodegradation, irrespective of the sources. To gain additional insight into the microbial transformation of the DOM, we also investigated the changes in the fraction's distribution for plankton, leaf litter and composite samples after the incubation. The results showed that biodegradation of hydrophilic fraction (Hi) causes an increase in the proportion of Ho (HoA, HoN), while biodegradation of HoA increases the HoN production.

• Journal of Microbiology and Biotechnology
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• v.24 no.8
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• pp.1034-1043
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• 2014

This study determined the effect of light intensity and photoperiod on the dry cell weight and total amount of carotenoids in four isolates of purple non-sulfur bacteria obtained from shaded and exposed microhabitats of a mangrove ecosystem in Kota Kinabalu, Sabah, Malaysia. The initial isolation of the bacteria was carried out using synthetic 112 medium under anaerobic conditions (2.5 klx) at $30{\pm}2^{\circ}C$. On the basis of colony appearance, cell morphology, gram staining, motility test, and 16S rRNA gene sequencing analyses, all four bacteria were identified as Afifella marina. One of the bacterial isolates, designated as Af. marina strain ME, which was extracted from an exposed mud habitat within the mangrove ecosystem, showed the highest yield in dry cell weight ($4.32{\pm}0.03g/l$) as well as total carotenoids ($0.783{\pm}0.002mg/g$ dry cell weight). These values were significantly higher than those for dry cell weight ($3.77{\pm}0.02g/l$) and total carotenoid content ($0.706{\pm}0.008mg/g$) produced by the isolates from shaded habitats. Further analysis of the effect of 10 levels of light intensity on the growth characteristics of Af. marina strain ME showed that the optimum production of dry cell weight and total carotenoids was achieved at different light intensities and incubation periods. The bacterium produced the highest dry cell weight of 4.98 g/l at 3 klx in 72 h incubation, but the carotenoid production of 0.783 mg/g was achieved at 2.5 klx in 48 h incubation. Subsequent analysis of the effect of photoperiod on the production of dry cell weight and total carotenoids at optimum light intensities (3 and 2.5 klx, respectively) revealed that 18 and 24 h were the optimum photoperiods for the production of dry cell weight and total carotenoids, respectively. The unique growth characteristics of the Af. marina strain ME can be exploited for biotechnology applications.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.124-132
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• 2023

In order to support start-ups effectively with limited resources, it is necessary to provide support tailored to start-up companies. Businesses that are operating in local incubation centers may have different demands for the support depending on the region characteristics. This study was worked on companies that have entered into the incubation center 'Youth Cube', which is operated by Ansan City. We investigated the perception of importance in the field of support to identify support policy priorities, and the satisfaction level of each field of support currently supported. Then We conducted an IPA analysis to derive the direction of support. The Ansan area has regional characteristics that it is located in the metropolitan area with well-equipped start-up infrastructure and many innovative institutions, As a result of the importance survey, technology commercialization was recognized as the most important, and education/mentoring was recognized as the least important. Satisfaction with the space and facilities that can be used free of charge was the highest, and the satisfaction was the lowest for entrepreneurship education/mentoring, as was the degree of importance. In addition, according to each quadrant, we derived support that should be maintained, support that should be intensively improved, support that should be given a low policy priority, and support directions that should be kept in mind to avoid excessive support.

• Journal of Mushroom
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• v.16 no.2
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• pp.96-102
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• 2018

Sparassis latifolia is one of the most expensive mushrooms in Korean market owing to its high ${\beta}$-glucan content and immunoactivity. However, because of the long cultivation period and high contamination rates, it has low production efficiency. Therefore, we first need to establish the optimum conditions for liquid spawn production to increase its production efficiency. As a result of experiments, molasses culture medium was selected for mycelial growth. Also, the optimum sugar content for molasses and amount of aeration used were approximately 8 Brix% and 0.3~0.6 vvm, respectively. Mycelial dry weight increases, while the medium decreases, as the incubation period increases. Therefore, to achieve maximum production efficiency, the incubation period of 9 to 11 days is appropriate.