• Title/Summary/Keyword: digestion

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Digestion Pattern of Antihypertensive Angiotensin I-Converting Enzyme Inhibitory Peptides from Saccharomyces cerevisiae in a Successive Simulated Gastricintestinal Bioreactor

  • Jang, Jeong-Hoon;Jeong, Seung-Chan;Lee, Jung-Kee;Lee, Jong-Soo
    • Mycobiology
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    • v.39 no.1
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    • pp.67-69
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    • 2011
  • A cell-free extract of Saccharomyces cerevisiae containing the angiotensin I-converting enzyme (ACE) inhibitory peptide was treated in a successive simulated gastric-intestinal bioreactor (step 1: amylase digestion, step 2: gastric fluid digestion, step 3: intestinal fluid digestion) to illustrate the absorption pattern of antihypertensive ACE inhibitory peptide, and the ACE inhibitory activities of each step were determined. Total ACE inhibitory activities of step 1, step 2, and step 3 were 55.96%, 80.09%, and 76.77%, respectively. The peptide sequence of each steps was analyzed by MS/MS spectrophotometry. Eleven kinds of representative peptide sequences were conserved in each step, and representative new peptides including RLPTESVPEPK were identified in step 3.

A Study on Usage of Results from Batch Reactor for Design of Aerobic Digestion (호기성 소화조 설계시 회분식 반응조에서 획득된 결과의 이용방안에 관한 연구)

  • Choung, Youn-Kyoo;Ko, Kwang-Baik;Park, Joon-hong
    • Journal of Korean Society of Water and Wastewater
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    • v.8 no.3
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    • pp.1-8
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    • 1994
  • In the general process of design for aerobic digestion, the design for field plant of which inflow pattern is continuous inflow is performed using the results from lab scale batch reactor. However, the recent researchers reported that the general designs were performed as over-estimated, Therefore, in this study, laboratory batch experiments were carried out at $20^{\circ}C$ and pH 7.5 on the aerobic digestion of waste activated sludge at different solid levels. This treatise could consider the negligence about effective digestion periods the usage of VSS as solid concentration, and the effect of initial solid concentration of solid degration rate coefficient($k_d$) as reasons of the overestimated design, and showed the scheme of how to design for aerobic digestion from batch experiment.

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A Study on Kinetics in One-Phase Anaerobic Digestion (단상 혐기성 소화공정에서의 동력학적 연구)

  • 조관형;조영태
    • Journal of Environmental Science International
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    • v.9 no.1
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    • pp.75-80
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    • 2000
  • Kinetic data for the acid phase anaerobic digestion were presented in this study and the constants were determined with acid production rate and gas production rate. Process models based on continuous culture theory were used to describe the characteristics of the acid forming microorganisms and to enable further development toward utilization of the process in a more rational manner. Acid phase digestion can be separated with appropriate manipulation of hydraulic retention time in anaerobic digestion. Kinetic analysis of data from the various hydraulic retention times using a phase specific model obtained form the acid phase indicated maximum specific growth rate of 0.40/h, saturation constant of 2,000mgCOD.$\ell$, yield coefficient of 0.35 mgVSS/msCOD utilized and decay constant of 0.04/h for the acid production rate. Similar analysis of data for the gas production rate indicated maximum specific growth rate of 0.003/h, saturation constant of 2,200mgCOD/$\ell$, yield coefficient of 0.035 mgVSS/mgCOD utilized and decay constant of 0.06/h.

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Understanding Starch Utilization in the Small Intestine of Cattle

  • Harmon, David L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.7
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    • pp.915-922
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    • 2009
  • Ruminants possess the capacity to digest very large amounts of starch. However, in many cases diets approach 60% starch and even small inefficiencies present opportunities for energetic losses. Ruminal starch digestion is typically 75-80% of starch intake. On average, 35-60% of starch entering the small intestine is degraded. Of the fraction that escapes small-intestinal digestion, 35-50% is degraded in the large intestine. The low digestibility in the large intestine and the inability to reclaim microbial cells imposes a large toll on post-ruminal digestive efficiency. Therefore, digestibility in the small intestine must be optimized. The process of starch assimilation in the ruminant is complex and remains an avenue by which increases in production efficiency can be gained. A more thorough description of these processes is needed before we can accurately predict digestion occurring in the small intestine and formulate diets to optimize site of starch digestion.

Roles of Milk Fat Globule Membrane on Fat Digestion and Infant Nutrition

  • Chai, Changhoon;Oh, Sejong;Imm, Jee-Young
    • Food Science of Animal Resources
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    • v.42 no.3
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    • pp.351-371
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    • 2022
  • Milk fats are present as globules emulsified in the aqueous phase of milk and stabilized by a delicate membrane architecture called milk fat globule membrane (MFGM). The unique structure and composition of the MFGM play an important role in fat digestion and the metabolic programming of neonates. The objective of this review is to compare the structure, composition, and physicochemical characteristics of fat globules in human milk, bovine milk, and infant formula. It provides an overview of the fat digestion process and enzymes in healthy infants, and describes the possible roles of the MFGM in association with factors affecting fat digestion. Lastly, the health benefits of the MFGM on infant nutrition and future perspectives are discussed with a focus on brain development, metabolic response, and gut health.

Comparative Analysis of Performance and Microbial Characteristics Between High-Solid and Low-Solid Anaerobic Digestion of Sewage Sludge Under Mesophilic Conditions

  • Lu, Qin;Yi, Jing;Yang, Dianhai
    • Journal of Microbiology and Biotechnology
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    • v.26 no.1
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    • pp.110-119
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    • 2016
  • High-solid anaerobic digestion of sewage sludge achieves highly efficient volatile solid reduction, and production of volatile fatty acid (VFA) and methane compared with conventional low-solid anaerobic digestion. In this study, the potential mechanisms of the better performance in high-solid anaerobic digestion of sewage sludge were investigated by using 454 high-throughput pyrosequencing and real-time PCR to analyze the microbial characteristics in sewage sludge fermentation reactors. The results obtained by 454 highthroughput pyrosequencing revealed that the phyla Chloroflexi, Bacteroidetes, and Firmicutes were the dominant functional microorganisms in high-solid and low-solid anaerobic systems. Meanwhile, the real-time PCR assays showed that high-solid anaerobic digestion significantly increased the number of total bacteria, which enhanced the hydrolysis and acidification of sewage sludge. Further study indicated that the number of total archaea (dominated by Methanosarcina) in a high-solid anaerobic fermentation reactor was also higher than that in a low-solid reactor, resulting in higher VFA consumption and methane production. Hence, the increased key bacteria and methanogenic archaea involved in sewage sludge hydrolysis, acidification, and methanogenesis resulted in the better performance of high-solid anaerobic sewage sludge fermentation.

Simultaneous Determination of Sulfur, Phosphorus, and Zine in Lubricating Oils by Microwave Digestion System and ICP-AES (마이크로파 분해장치와 유도결합 플라스마 원자방출분광법을 이용한 윤활유 시료 중 S, P 및 Zn의 동시 분석)

  • Cho, Sung-Ill;Lim, Heon-Sung;Lee, Sueg-Geun
    • Analytical Science and Technology
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    • v.14 no.4
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    • pp.324-330
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    • 2001
  • For the analysis of S, P and Zn in lubricating oil, microwave digestion method was studied by using inductively coupled plasma-atomic emission spectrometry(ICP-AES). Lubricating oil was completely decomposed with nitric acid or a mixture of nitric acid and hydrogen peroxide using and closed microwave digestion system. Digestions are completed within 50 min, a factor of at least 3~4 times faster than for the conventional digestion. A gradual heating program operated by the pulsed mode was found suitable for decomposing the lubricating oil matrix safely. The proposed method of digestion gave relative standard deviations(RSD) less than 3% for the elements determined.

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Optimization of Enzyme Digestion Conditions for Quantification of Glycated Hemoglobin Using Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry

  • Jeong, Ji-Seon
    • Mass Spectrometry Letters
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    • v.5 no.2
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    • pp.52-56
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    • 2014
  • Glycated hemoglobin (HbA1c) is used as an index of mean glycemia over prolonged periods. This study describes an optimization of enzyme digestion conditions for quantification of non-glycated hemoglobin (HbA0) and HbA1c as diagnostic markers of diabetes mellitus. Both HbA0 and HbA1c were quantitatively determined followed by enzyme digestion using isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) with synthesized N-terminal hexapeptides as standards and synthesized isotope labeled hexapeptides as internal standards. Prior to quantification, each peptide was additionally quantified by amino acid composition analysis using ID-LC-MS/MS via acid hydrolysis. Each parameter was considered strictly as a means to improve digestion efficiency and repeatability. Digestion of hemoglobin was optimized when using 100 mM ammonium acetate (pH 4.2) and a Glu-C-to-HbA1c ratio of 1:50 at $37^{\circ}C$ for 20 h. Quantification was satisfactorily reproducible with a 2.6% relative standard deviation. These conditions were recommended for a primary reference method of HbA1c quantification and for the certification of HbA1c reference material.