• KSBB Journal
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• v.15 no.3
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• pp.274-279
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• 2000

A Saccharomyces cerevisiae isolated from a feed additive yeast product was cultivated in a Korean paper digestion wastewater in order to investigate the possibility of using it as substrate for the yeast. The yeast couldn't grow in the wastewater. It could grow in the wastewater diluted and the optimum dilution rate was 7.5 In batch cultivation with the jar fermenter the maximum total cell count was $1.34{\times}107/mL$ was obtained by the addition of undiluted digestion wastewater. By adding $(NH_4)_2S0_4 and KH_2P0_4$together with the undiluted wastewater the maximum cell concentration could be obtained faster.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.1
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• pp.75-82
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• 1995

Two digestion trials were conducted to investigate the effect of feeding heated soybean meal (HSBM) on ruminal and post-ruminal digestion of organic matter (OM) and nitrogen (N), bacterial N flow to the duodenum and N balance in young calves weaned at 6 weeks of age. In trial 1, calves were fed concentrate diets containing soybean meal (SBM) or HSBM and hay mixed in the ratio of 6:4 to support daily weight gain of 0.5 kg. The same concentrate diets were used in trial 2, but the ratio of concentrate to hay was 7:3 to support body weight gain of 0.7 kg/d. Measurements were made 10 and 13 weeks of age in trial 1, and at 10 and 15 weeks in trial 2. Ruminal OM digestibility increased with advancing age in both trials. Ruminal OM digestion was not affected by the diets in trial 1, but it was greater for the SBM diet than for the HSBM diet at 10 weeks in trial 2. Net N loss from the rumen was lover for the HSBM diet than for the SBM diet in trial 1, but it was not affected by the diets in trial 2. Bacterial N flow to the duodenum, N digestion in the total digestive tract and N retention were not affected by the diets in either of the trials.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.3
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• pp.102-115
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• 1990

Importance of anaerobic digestion as an energy generating device has been increased as fuel shortage becomes serieous. Several modification methods on the conventional digesters including Powdered Activated Carbon (PAC) addition and two-phase digestion were studied to enhance the gas production. This study investigated the effects of PAC on anaerobic digestion of chicken manure in terms of gas production and sludge stabilization. As a first experiment, an optimum PAC dose for efficient gas production was determined in a batch test. In semi-continuous experiments, an optimum Sludge Retention Time (SRT) at that PAC concentration and an overall substate utilization rate coefficient were investigated. A portion of gas increased by PAC addition was estimated using a substrate utilization rate coefficient of microorganisms attached on PAC. This test was performed in batch experiments using acetic acid as a substrate. The digesters for all experiments were kept 35${\pm}$ 1˚C in a heated water bath. Mixing was performed manually once a day and the produced gas was collected for daily reading. The following conclusions were made for this study. 1. Cptimum PAC concentration was 5% total solids, where gas production rate was increased by 20 percents. 2. Optimum SRT was 7.5 days. 3. Substrate utilization rate coefficient of microorganisms attached on PAC was about twice as much as that of suspended ones.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.2
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• pp.94-99
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• 2015

The performance of chamber and bag digesters for solid state anaerobic digestion (SS-AD) of separated solid fraction of swine manure was investigated using lab-scale digester (4,460 mL total volume and 1,800 mL of effective volume) operating at $37^{\circ}C$ for 63 days. The performance of two different digester types was evaluated in terms of the kinetic constants of methane production obtained from the Gompertz and Gaussian equations. Methane production potential of chamber and bag digester was 202 and $218N{\cdot}mL$ $CH_4/g$ VS. Time to produce 95% methane production potential (T95) and calculated effective anaerobic digestion time were 55.5 days and 41.8 days for chamber digester and 52.8 days and 43.5 days for bag digester, respectively. Our results reveal that the performance was not significantly different between chamber and bag digester.

• Journal of Biosystems Engineering
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• v.43 no.2
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• pp.110-118
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• 2018

Purpose: In this study, the potential for biogas production, degradation rates, and lag-phase of diauxic growth of carbohydrate-based material, which is one of the proximate compositions, were investigated. Methods: This study was conducted using starch as a carbohydrate-based material. In experimental condition 1, the biogas potential of carbohydrate-based material was measured. In experimental condition 2, the effect of feed to microorganism ratio (F/M ratio) on lag-phase of diauxic growth from carbohydrate-based material was tested. Biochemical methane potential tests were performed at five different feed to microorganism ratios (0.2, 0.4, 0.6, 0.8, and 1.0) under mesophilic conditions. The biogas production patterns, lag-phase, total volatile fatty acids to total alkalinity ratio (TVFA/TA ratio), and time required for 90 percent biogas production were used to evaluate biogas production based on the biochemical methane potential tests. Results: In experimental condition 1, unlike previous studies, biogas was produced in the TVFA/TA ratio ranging from 1.131 to 2.029 (approximately 13-19 days). The methane content in the biogas produced from the digesters was 7% on day 9 and increased rapidly until approximately day 27 (approximately 72%). In experimental condition 2, biogas yield was improved when the feed to microorganism ratio exceeded 0.6, with an initial lag-phase. Conclusions: Even if the TVFA/TA ratio was greater than 1.0, the biogas production was processed continuously, and the $CO_2$ content of the biogas production was as high as 60%. The biogas yield was improved when the F/M ratio was increased more than 0.6, but the lag-phase of carbohydrate-based material digestion became longer starting with high organic loading rate. To clarify the problem of the initial lag-phase, our future study will examine the microbial mechanisms during anaerobic digestion.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.135-144
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• 1999

The purposes of this study were to survey types of pretreatment methods adopted by industrial hygiene laboratories in Korea for extracting heavy metals in welding fume samples and to compare performances of two pretreatment methods, the acid extraction and the microwave digestion, in extracting heavy metals contained in the real workplace samples from various welding jobs including arc, argon, and carbon dioxide. A total of 25 analytical chemists in the industrial hygiene laboratories participating the quality control program directed by the Korea Industrial Safety Corporation were interviewed by telephone. For the purpose of comparing performance of extracting heavy metals from real workplace samples, a total of 53 welders from 21 workplaces located in Anyang, Uiwang, and Kunpo areas were sampled from the period of March 22, 1999 to April 20, 1999. It was found that the most frequently adopted method for samples from the quality control program was the acid extraction method(40%) followed by the NIOSH 7300 method(36%). The NIOSH method, however, was the dominant method(36%) for samples from workplace followed by the acid extraction method(28%). In this study, two extraction methods, the acid extraction and the microwave digestion, were compared in terms of recovery rate, accuracy, and precision for both manganese and chromium. Both methods produced comparable results for the samples prepared for the quality control program. In contrast, concentrations of two heavy metals determined from real workplace samples pretreated with the microwave digestion method were statis tically significantly higher, manganese(166%) and chromium (200%), than those of utilizing the acid extraction method. These findings were consistent regardless of types of welding techniques used. The results of this study clearly show the importance of verifying the analytical performances of extraction methods for heavy metals not only for the samples from the quality control program but also from the real world samples collected from welding jobs.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.510-521
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• 1998

The effects of two types of protein, soybean meal (SBM) and fish meal (FM); and two types of energy supplements, corn flour (CF) and paper pulp (PP), on intake of guinea grass (Panicum maximum), fibre digestion and microbial activities in four Merino rams with an average weight of $54.4{\pm}4.5kg$ were studied. Each animal was fitted with a ruminal cannula and a duodenal cannula at the proximal position. The animals were fed twice daily with chopped guinea grass (5 cm) ad libitum and one of the four dietary supplements: 170 g FM+268 g PP; 170 g FM+268 g CF; 200 g SBM+200 g PP or 200 g SBM+200 g CF. All the supplements were mixed with 100 g molasses. In sacco and in vivo digestibilities, digesta flow rates, fermentation and microbial population were studied in a $4{\times}4$ Latin square design with a $2{\times}2$ factorial arrangement of dietary treatments. The effects of energy or protein sources were not significant on grass intake of sheep. The potential degradabilities of NDF and ADF were not significantly affected by any of the supplements. However, the energy and protein sources had significant efects on disappearance rate of NDF and ADF. The disappearance rate of both NDF and ADF were significantly (p < 0.05) higher in animals fed PP when compared to animals fed CF. Animals fed FM also showed significantly (p < 0.03) higher disappearance rate of ADF than those fed SBM. Animals fed PP showed better digestion in the rumen and total tract. Total flow of NDF and ADF through the duodenum was not significantly affected by the various supplements. The mean rumen pH values (5.8-6.1) were not significantly different among the four different diets. The concentration of rumen ammonia was significantly (p < 0.0001) higher in animals fed SBM (235-266.4 mg N/L) supplement than in animals fed FM (174.9-179.7 mg N/L), while total VFA concentration was not significantly affected by both energy and protein supplements. Mean values of total VFA ranged from 72.5-82.3 mM. Molar proportions of acetate, propionate and butyrate were typical of a roughage type fermentation. Molar proportion of acetate was significantly (p < 0.0001) higher in sheep fed PP when compared to sheep fed CF. Animals fed FM had higher total viable bacterial counts, while animals fed CF showed higher protozoal numbers. Proportions of cellulolytic bacteria were only slightly higher in animals fed SBM or PP.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1396-1404
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• 2017

Objective: This study was determined the influence of virginiamycin supplementation on growth-performance and characteristics of digestion of cattle with decreasing dietary net energy value of the diet for maintenance ($NE_m$) from 2.22 to 2.10 Mcal/kg. Methods: Eighty crossbred beef steers ($298.2{\pm}6.3kg$) were used in a 152-d performance evaluation consisting of a 28-d adaptation period followed by a 124-d growing-finishing period. During the 124-d period steers were fed either a lesser energy dense (LED, $2.10Mcal/kg\;NE_m$) or higher energy dense (HED, $2.22Mcal/kg\;NE_m$) diet. Diets were fed with or without 28 mg/kg (dry matter [DM] basis) virginiamycin in a $2{\times}2$ factorial arrangement. Four Holstein steers ($170.4{\pm}5.6kg$) with cannulas in the rumen (3.8 cm internal diameter) and proximal duodenum were used in $4{\times}4$ Latin square experiment to study treatment effects on characteristics of digestion. Results: Neither diet energy density nor virginiamycin affected average daily gain (p>0.10). As expected, dry matter intake and gain efficiency were greater (p<0.01) for LED- than for HED-fed steers. Virginiamycin did not affect estimated net energy value of the LED diet. Virginiamycin increased estimated NE of the HED diet. During daylight hours when the temperature humidity index averaged $81.3{\pm}2.7$, virginiamycin decreased (p<0.05) ruminal temperature. Virginiamycin did not influence (p>0.10) ruminal or total tract digestion. Ruminal (p = 0.02) and total tract digestion (p<0.01) of organic matter, and digestible energy (p<0.01) were greater for HED vs LED. Ruminal microbial efficiency was lower (p<0.01) for HED vs LED diets. Conclusion: The positive effect of virginiamycin on growth performance of cattle is due to increased efficiency of energy utilization, as effects of virginiamycin on characteristics of digestion were not appreciable. Under conditions of high ambient temperature virginiamycin may reduce body temperature.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.29-34
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• 1970

In order to prepare digested Protein source for the Weanling Food from soybean, an attempt was made to decompose steamed soybean protein to amino acids and peptides by protease and cellulase produced from Aspergillus niger and Aspergillus sojae. In this paper, the optimum condition for digestion of soybean protein were studied and also investigated the effects of decolorization of it. As the results, followings were obtained; 1. As steaming conditions, a treatment under 15 lb of pressure and 10 minutes of heating shows most effective. 2. The optimum pH of Asp, sojae enzyme for the digestion of soybean protein is 6.0, while that of Asp. niger enzyme is 4.4. In successievly-decomposing with Asp. sojae and Asp. niger, it shows the most effective on ratio of water-soluble-nitrogen to total nitrogen and amino-nitrogen to total nitrogen than any other separate treatments. 3. The suitable amount of the enzyme solution to that of the soybean substrate paste, in volume, is 1 : 2. 4. Digestion ratio of soybean protein indicates the gradual and steady effects of increasing time of digestion, but 8 hour-digestion regarding to putrefaction was suitable. 5. The most effective decolorization was successively passed on culumns of active carbon and anion exchanger (Dowex 2-x-8) at room temperature. In separate treatments, the effective order of decolorization was as follows; (Dowex 2-x-8)>Active carborn>Amberite IR-120 6. The powder type of the soy protein source obtained by concentration below $60^{\circ}C$ contains 12.51% of moisture, 66.31% of protein, 4.25% of fat, 12.75% of carbohydrate, 4.18% of ash.

• KSBB Journal
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• v.22 no.2
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• pp.97-101
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• 2007

This study was performed to examine the availability of anaerobic digestion of the remainders caused by bacterial cellulose production process using food wastes. They maybe to be considered as others second pollution sources. Thus, this study was targeted to minimize content of organic material and to obtain more energy in those remnants using two-phase UASB reactor. The working volume of first hydrolysis fermentor was 35 L (total 55 L) and the second methane fermentor was 40 L (total 50 L). The organic loading rate of hydrolysis fermentor was 3 g-VS/L${\cdot}$day and 25,000 ppm of $COD_{cr}$ for methane fermentor. The hydraulic retention time was 18 days for hydrolysis reactor and 33 days for methane reactor. The hydrolysis reactor and methane reactor were performed at 35, 40$^{\circ}C$ respectively. For the efficient stable performance, the composition of organic wastes at each stage was as follow; Food waste with bacterial culture remnants (1 : 1), bacterial cellulose remnants, bacterial cellulose culture remnants with food wastes saccharified solids (1 : 1). When the anaerobic digestion was performed stably at each stage, the COD removal efficiency was 88, 90, 91 % respectively. At this time, methane production rate was 0.26, 0.34, $0.32m^3\;CH_4/kg-COD_{remove}$. As well as the values of anaerobic digestion at third stage were more higher than values of anaerobic digestion using food wastes. It is clearly to say that the food wastes zero-emission system constructed in our lab is more efficient way to treat and reclaim food wastes.