• Asian-Australasian Journal of Animal Sciences
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• 제28권10호
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• pp.1442-1448
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• 2015

The objectives of this study were to determine the molecular weight of condensed tannins (CT) extracted from mangosteen (Garcinia mangostana L) peel, its protein binding affinity and effects on fermentation parameters including total gas, methane ($CH_4$) and volatile fatty acids (VFA) production. The average molecular weight ($M_w$) of the purified CT was 2,081 Da with a protein binding affinity of 0.69 (the amount needed to bind half the maximum bovine serum albumin). In vitro gas production declined by 0.409, 0.121, and 0.311, respectively, while CH4 production decreased by 0.211, 0.353, and 0.549, respectively, with addition of 10, 20, and 30 mg CT/500 mg dry matter (DM) compared to the control (p<0.05). The effects of CT from mangosteen-peel on in vitro DM degradability (IVDMD) and in vitro N degradability was negative and linear (p<0.01). Total VFA, concentrations of acetic, propionic, butyric and isovaleric acids decreased linearly with increasing amount of CT. The aforementioned results show that protein binding affinity of CT from mangosteen-peel is lower than those reported for Leucaena forages, however, the former has stronger negative effect on IVDMD. Therefore, the use of mangosteen-peel as protein source and $CH_4$ mitigating agent in ruminant feed requires further investigations.

• Korean Chemical Engineering Research
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• 제54권2호
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• pp.248-254
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• 2016

오늘날 폐수처리는 슬러지의 증가와 환경규제의 이유로 매우 중요해지고 있다. 슬러지처리는 폐수처리플랜트에 있어서 운영비의 50%를 차지하므로 슬러지 분해에 있어서 경제성 있는 방법이 대두되고 있다. 습식산화 반응은 폐수의 유기물을 효과적으로 제거해주고 슬러지 분해 뿐만 아니라 바이오연료의 전구체로 쓰일 수 있는 휘발성 유기산이 부산물로도 나온다. 습식산화 반응은 고온 고압의 높은 조건의 단점이 존재하지만 중력식 반응기를 통한 수두압으로 운영비를 줄일 수 있다. 본 연구에서는 상용프로그램인 Aspen Plus를 이용하여 아임계 조건에서 PSRK 상태방정식을 이용하여 공정모사 하였다. 중력식 반응기의 길이, 산화제 종류, 슬러지 유량과 산화제 주입 위치에 따라 사례 연구를 해보았으며 중력식 반응기 1000 m, 유량이 2 ton/h일 때에 유기물의 전환률은 92.02%, 유기산 효율은 0.17 g/g이였다.

• 한국작물학회지
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• 제61권4호
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• pp.242-250
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• 2016

새로운 식품 소재의 개발을 목적으로 향미벼 신품종을 이용하여 발아현미를 제조하고 발아 전 후 종실에 함유된 향기성분과 생리활성 물질, 그리고 지방산 조성의 변화를 관찰한 결과는 다음과 같다. 1. 향기성분은 발아 전 52개, 발아 후 51개 등 총 56개 성분이 동정되었으며 이들은 hydrocarbon(29%)과 alcohol(23%) 및 aldehyde(21%)류로 분류되었으며, 주요 향기성분으로는 nonanal, benzene, 1-octanol, 1-hexanol, furan, decanal 등이 동정되었다. 2. 발아로 인하여 heptane,3,3,5-trimethyl, 1-pentadecene, 2-heptanone 등 13개 성분은 함량이 증가한 반면, 향미벼 특유의 팝콘향을 나타내는 2-acetyl-1-pyrroline을 비롯하여 1-nonanol, 1-heptanol, 1-hexanol 등 39개 성분은 발아로 인하여 함량이 감소하였다. 3. 향기 성분의 함량을 이용한 PLS-DA 분석 시 뚜렷하게 향기 특성에 따라 발아 전과 발아 후의 구별이 가능하였으며, 2-acetyl-1-pyrroline, 2-octanone 등은 발아 전의, 그리고 benzaldehyde, tridecene 등은 발아 후의 특징적인 향기성분으로 나타났다. 4. 발아된 향미벼의 campesterol, stigmasterol, sitosterol 등 phytosterol류와 squalene, 그리고 5종의 tocols 등 생리활성물질 함량은 모두 발아 전에 비해 낮은 것으로 나타났다. 5. 향미벼의 주요 지방산은 linoleic, oleic 및 palmitic acid였으며 발아로 인하여 linoleic acid와 oleic acid는 각각 1.3%, 2.7%의 증가하고 palmitic acid는 3.7%의 조성 비율이 감소하는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제5권4호
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• pp.687-693
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• 1992

The study was conducted to investigate the effect of soybean meal (SBM) supplementation on the voluntary intake of rice straw and ruminal fermentation characteristics. Balance trials were conducted with three Hapanese Corriedale wethers fed a rice straw alone (control), rice straw supplemented with 75 and 150 g of SBM/day in a $3{\times}3$ latin square design. Voluntary intake of rice straw in sheep fed both levels of SBM supplemented diets was significantly higher (p<0.05) than that in sheep fed control diet. Crude protein digestibility was significantly increased (p<0.05), but organic matter, crude fibre, neutral detergent fibre and acid detergent fibre digestibilities were not affected by SBM supplementation. Nitrogen balance was positive in sheep on both levels of SBM supplemented diets, but negative in animals on the control diet. Rumen ammonia and blood urea-nitrogen concentrations increased (p<0.05) as increasing level of SBM. Total volatile fatty acids, acetate, propionate, butyrate and valerate concentrations in rumen fluid were also significantly increased (p<0.01), but ruminal pH was decreased (p<0.05) by SBM supplementation.

• Journal of Biosystems Engineering
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• 제35권1호
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• pp.53-63
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• 2010

The performance of two serial completely stirred tank reactors (CSTRs) for treatment of swine manure (SM) with Chinese cabbage silage (CCS) was studied. The two CSTRs of 41 liters each were connected in series and first reactor was fed swine manure with Chinese cabbage silage in 3:1 proportion by VS basis. The FOS/TAC, methane content (%) and pH were utilized as the parameters for the digester stability control. The FOS/TAC value was found to be effective indicator for instant digester condition. The stability of reactors can be obtained with the FOS/TAC value up to 1.0 with accumulation of FOS value below 10,000 mg/L. Material exchange method was effective in transferring the excess volatile fatty acids (VFA) from the first reactor to the second one and maintaining stability in both the reactors. The biogas yield and the methane yield was 0.55-0.61 and 0.41-0.42 L/g VS fed, respectively, at organic loading rate (OLR) of 2.2-2.6 g VS/L with total HRT of 32 days.

• Journal of Microbiology and Biotechnology
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• 제24권5호
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• pp.629-638
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• 2014

This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at $50^{\circ}C$ for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.

• Asian-Australasian Journal of Animal Sciences
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• 제13권11호
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• pp.1508-1513
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• 2000

The aim of this trial was to study the response of laboratory animals including omnivores (rats) and herbivores (rabbits, guinea pigs and hamsters) to the same level of dietary fiber on their digestive enzymes and hindgut fermentation. Ten weanling animals of each of four species, rabbits, guinea-pigs, rats and Syrian hamster, were fed a basal diet of 18% crude protein and 10% crude fiber for six weeks. The digesta and tissue of each intestinal segment were collected to measure the activity of digestive enzymes. Rabbits contained the highest secreted pepsin activity in the stomach, whereas rats contained the highest protease and ${\alpha}-amylase$ activity in the small intestine, and lower fibrous hydrolases in the hindgut than rabbits, guinea pigs and hamsters. The total VFA productions in the caecum and colon were highest in rats, followed by hamsters and rabbits, while the guinea pigs contained the lowest VFA and a different pattern of VFA molar ratio from the other laboratory animals. The degree of hindgut fermentation in these laboratory animals was in reverse to the trend for their fiber digestion.

• Asian-Australasian Journal of Animal Sciences
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• 제10권4호
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• pp.371-377
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• 1997

Objective of the present study were to investigate effects of different levels of concentrate in complete rations on nutrient digestibilities and ruminal fermentation in sheep and growth performance in Korean native bulls. Increasing levels of concentrate (35, 50, 65, and 80% of complete rations) improved digestibilities of dry matter (DM), crude protein (CP) and ether extract (EE) without affecting digestibility of neutral detergent (NDF) and acid detergent fiber (ADF). Increasing levels of concentrate decreased ruminal fluid pH but increased concentrations of $NH_3-N$, propionic acid, and total volatile fatty acids (VFA). Both the disappearance rates of DM and nitrogen (N) in an in sacco study were linearly increased as the levels of concentrate in complete rations increased. Meanwhile, increasing levels of concentrate in complete rations improved growth rate and feed conversion ratio in Korean native bulls. In conclusion, the complete rations containing 80% concentrate showed better digestibility and energy supply than those of the lower levels (35, 50 and 65%) of concentrate of the rations, resulting in improved growth performance of Korean native bulls.

• 환경위생공학
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• 제24권4호
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• pp.80-89
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• 2009

In the organic waste, food waste is the most difficult controls. In the study, food waste was treatmented to removal only the dockage. To decrease the hydrogen sulfide($H_2S$) in the produced biogas, iron chloride put in the anaerobic digester. Respectively treatment quantity of the food waste, content of the methane($CH_4S$) gas in the biogas, produced gases quantity, put in the quantity of the Iron chloride, pH, TS, Alkalinity, VFA, Ammonia. The results obtained from the experiment are as follows: 1. The produced biogases quantity/the treatment quantity of the food waste was $83.82{\sim}129.41m^3/ton$. 2. The content of the hydrogen sulfide($H_2S$) in the produced biogas is below of the 500ppm. The iron chloride put in the anaerobic digester. 200~300kg of the iron chloride put in the anaerobic digester at the steady-state. 400~850kg of the iron chloride put in the anaerobic digester at the unsteady-state. 3. Factor of the operator was the pH: 7.7~8.4, content of mathane: 55~65%. 4. TS(total solid) of the digestor sludge was 17~20%, Alkalinity was 38,500~41,750ppm, VFA(Volatile Fatty Acids) was 2,800~2,420ppm, Ammonia was 4,300~3,650ppm.

• 한국환경보건학회지
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• 제23권3호
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• pp.40-49
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• 1997

In Korea, naked barley and tapioca are main raw materials for the production of fermentation ethyl alcohol, and one million drums bf 95% fermentation ethyl alcohol is produced per year by use of them. Stillage of alcoholic fermentation is mostly digested by methane fermentation process, and methane gas occured if methane fermentation process is recovered and mixed with fuel to decrease 25-30% for total fuel used in factories. In the anaerobic digestion process of naked barley stillage, supplement of nutrients is necessary to slove the problems caused by inhibitory materials contained if stillage and deficiency of nutrients. Therefore, the objective of this study was to examine why the anaerobic digesters using the naked barley distillery wastewater have shown the poor digestability frequently and how to control it. As the poor digestion was supposed to be occurred by the lack of iron as trace nutrient, the experiments were carried out to find out the optimum dosage and the way of addition of iron and to assess the quantitative evaluation of the type of iron in digesters. Initially, bottle test as batch digesters and lab-scaled continuous flow digesters were used in order to determine the digestion characteristics with tapioca and naked barley distillery wastewater. According to the results of batch tests, the poor digestion was caused by volatile fatty acids and could be improved by adding of calcium. The activity of the methanogenic bacteria were increased remarkably when the iron was added to the digester in the form of mixture with substrates.