• Development and Reproduction
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• v.11 no.3
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• pp.253-261
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• 2007

Lactadherin is a glycoprotein of human milk fat globule membrane that binds to mucin and butyrophilin forming the protein complex. Especially, mucin and lactadherin in human milk efficiently protect infants with poor immune functions right after birth from infections by microorganisms and play important roles for their early survival, growth and development. Lactadherin inhibits the propagation and growth of rotavirus that is a global pathogen causing infants' diarrhea. Recently this protein was known to promote neovascularization and its deficiency related to develop Alzheimer's disease. In this study, the basic biochemical and physiological aspects of lactadherin were investigated. Messenger RNAs were isolated from mammary tissues from Korean women patients to clone a 1.2 kb cDNA and sequenced its DNA to determine its amino acid sequences. The cDNA was cloned to express its 43 kD protein in E. coli, which was confirmed by Western blot. The recombinant protein was purified and injected to 2 rabbits to raise antibodies against it. The semi-purified milk fat globule membrane proteins from Korean women was analyzed by Western blot using the rabbit antibody to give 70, 55, 46, 30 kD bands. Also several polymorphism and SNPs of lactadherin gene from Korean women were observed compared with those of Caucasian women.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.04a
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• pp.113.2-114
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• 1979

$\beta-Galactosidase$ is an enzyme which catalizes hydrolysis of lactose, a natural substrate, to glucose and galctose and transferring some monosac-charide units to active acceptors as sugar or alcohol. The occurence of $\beta-Galactosidase$ is known in various microorganisms, animals and higher plants and has been studied by many investigatigators. Especially, a great deal of articles for the enzyme of E. coli have been presented in genetic control mechanism and induction-repression effects of proteins, On the other hand, in the dairly products industry, it is important to hydrolyes lactosd which is the principal sugar of milk and milk products. During the last few years, the interest in enzymatic hydrolysis of milk lactose has teen increased, because of the lactose intolerence in large groups of the population. Microbial $\beta-Galactosidases$ are considered potentially most suitable for processing milk to hydrolyse lactose and, in recent years, the immobilized enzyme from yeast has been examined. Howev, most of the microbial $\beta-Gal$ actosidase are intracellular enzymes, except a few fungal $\beta-Gala-$ ctosidases, and extracellular $\beta-Galactosidase$ which may be favorable to industrial applieation is not so well investigated. On this studies, a mold producing a potent extracellular $\beta-Galactosidase$ was isolated from soil and identified as an imperfect fungus, Beauveria bassians. In this strain, both extracellular and intracellular $\beta-Galactosidases$ were produced simultaneously and a great increase of the extracellular production was acheved by improving the cultural conditions. The extracellular enzyme was purified more than 1, 000 times by procedures including Phosphocellulose and Sephadex G-200 chromatographies. Several characteristics of the enzymewas clarified with this preparation. The enzyme has a main subunit of molecular weight of 80, 000 which makes an active aggregate. And at neutral pH range, it has optimum pH for activity and stability. The Km value was determined to be 0.45$\times$10$^{-3}$ M for $o-Nitrophenyl-\beta-Galactoside.$ In any event, it is interesting to sttudy the $\beta-Galactosidase$ of B. bassiana for the mechanism of secretion and conformational structure of enzyme.

• Korean Journal of Veterinary Service
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• v.23 no.2
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• pp.165-170
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• 2000

This study was carried out to investigate the changes of physical and chemical properties according to the preserving periods and temperature in heat-treated market milks ($130^{\circ}C$, 2 sec). The market ilks were divided into 3 experimental groups, that is $4^{\circ}C$, $15^{\circ}C$ and $30^{\circ}C$ according to the preserving temperature during 7 days. There were analysed fat, protein, lactose, total solids, solids-not-fat, specific gravity and acid value of market milks in each experimental group. These observations indicated that heat-treated market milks ($130^{\circ}C$, 2 sec) may be acceptable physically and chemically after 7 days at $4^{\circ}C$. The results obtained were summarized as follows ; 1. Total microorganisms in market milks were found 12$\times$$10^1$ cells at 1st day Coliform and pathogenic bacteria were not detected. 2. Milk fats tended to decrease 3.69% to 3.48% according to the time lapsed in all experimental groups without concerning to the storage temperature. 3. Milk proteins were slowly decreased 3.18% to 3.13% according to the time lapsed without concerning to the storage temperature. 4. Milk lactose was slightly increased 4.41% to 4.55% in all experimental groups. 5. Specific gravity in market milks was 1.0316 to 1.0299, and showed no changes according to the preserving periods and temperature. 6. Total solids and solids-not-fat in market milks were slightly decreased 12.30 to 12.05 and 8.55 to 8.40. 7. Acid values were dramatically increased 0.1289 to 0.3116 at $30^{\circ}C$ storage group, while tended to be stable at $4^{\circ}C$ storage group for 7 days.

• Animal Bioscience
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• v.37 no.2_spc
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• pp.370-384
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• 2024

Rumen microbiota play a central role in the digestive process of ruminants. Their remarkable ability to break down complex plant fibers and proteins, converting them into essential organic compounds that provide animals with energy and nutrition. Research on rumen microbiota not only contributes to improving animal production performance and enhancing feed utilization efficiency but also holds the potential to reduce methane emissions and environmental impact. Nevertheless, studies on rumen microbiota face numerous challenges, including complexity, difficulties in cultivation, and obstacles in functional analysis. This review provides an overview of microbial species involved in the degradation of macromolecules, the fermentation processes, and methane production in the rumen, all based on cultivation methods. Additionally, the review introduces the applications, advantages, and limitations of emerging omics technologies such as metagenomics, meta-transcriptomics, metaproteomics, and metabolomics, in investigating the functionality of rumen microbiota. Finally, the article offers a forward-looking perspective on the new horizons and technologies in the field of rumen microbiota functional research. These emerging technologies, with continuous refinement and mutual complementation, have deepened our understanding of rumen microbiota functionality, thereby enabling effective manipulation of the rumen microbial community.

• Korean Journal of Agricultural Science
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• v.20 no.1
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• pp.56-67
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• 1993

To applying of genetic markers of milk proteins as dairy cow registration and selection aids for genetic improvement, genopypes controlling the 4 milk protein loci, ${\alpha}S1$-casein (${\alpha}S1$-CN), ${\beta}$-casein(${\beta}$-CN), ${\kappa}$-casein(${\kappa}$-CN), and ${\beta}$-lactoglobulin(${\beta}$-LG), from a total of 159 Holstein lactating cows reared at National Animal Breeding Station in 1992 were detected by polyacrylamide gel(PAGE) electrophoresis, and associations between genetic polymorphisms of milk proteins and milk compositions were analyzed. The observed distribution of phenotypes for ${\alpha}S1$-CN, ${\beta}$-CN, ${\kappa}$-CN and ${\beta}$-LG were agreement with those expected under the assumption of genetic equilibrium. The observed genotypic frequencies of the ${\alpha}S1$-CN BB, ${\beta}$-CN AA, ${\kappa}$-CN AA and ${\beta}$-LG AB genotypes were founded to be very high as 79.87%, 84.28%, 71.70% and 49.10%, respectively. Gene frequencies were 0.899 and 0.101 for ${\alpha}S1-CN^B$ and ${\alpha}S1-CN^C$, 0.921 and 0.079 for ${\beta}-CN^A$ and ${\beta}-CN^B$, 0.837 and 0.163 for ${\kappa}-CN^A$ and ${\kappa}-CN^B$, 0.378 and 0.622 for ${\beta}-LG^A$ and ${\beta}-CN^B$. According to the results of analysis of variance, the genotypes of the ${\alpha}S1-CN$, ${\beta}-CN$, ${\kappa}-CN$ and ${\beta}-LG$ were significantly difference for fat, protein and total solid percentage in milk compositions. On milk compositions, the ${\kappa}$-CN BB genotype was very high fat and protein percentage more than ${\kappa}$-CN AA and AB genotypes, and ${\beta}$-LG AA genotype was very high fat percentage more than ${\beta}$-LG AB and BB genotype at 5% level of significant difference, respectively. As a consequence, the fat and protein percentage may be improved to select to ${\kappa}$-CN BB and ${\beta}$-LG AA genotypes.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.305-307
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• 2007

Lactoferrin-binding proteins (LBP) has not been well characterized in Streptococcus uberis isolated from milk of bovine mastitis and to date this protein is considered to be an important virulence factor in Streptococcal mastitis. To determine the more efficient extraction method of LBP from four S. uberis strains, we used two different extraction methods (mutanolysin and sodium dodecyl sulfate) in this study. Bacterial proteins extracted were electrophoresed by 10% polyacrylamide gels in the presence of sodium deodecyl sulfate and gels were transferred onto nitrocellulose membrane. Rabbit anti-bovine lactoferrin antibody and HRP-conjugated donkey anti-rabbit IgG antibody were used to detect LBP. This Western blotting analysis demonstrates that extraction method with SDS extracted 110 kDa and 112 kDa LBPs more efficiently compared to the mutanolysin extraction method.

• Applied Biological Chemistry
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• v.29 no.1
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• pp.83-89
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• 1986

To investigate effectors on the colloidal stability of whey and soybean proteins, characteristics of tofu-gel formation, effects of heat treatment and salt composition on the colloidal stability, and effects of heat treatment on storage stability were analyzed. When experimental tofus were made from the mixture of whey and soybean, the calcium in the whey precipitated the soy proteins, and disrupted the gel formation, which resulted in the curd of poor texture. In the heat treatment at $60{\sim}100^{\circ}C$, whey and the whey proteins dialyzed against distilled water were readily preciptated at over $70^{\circ}C$, but the mixture of whey and soy extract as well as soy extract were stable at the range of temperature. The proteins of soy extract, whey dialyzed against sodium phosphate buffer, and the mixture were stable at the same heat treatment, and this suggested that phosphates in the soy extract stabilize specialty the whey proteins. Soy proteins were easily destabilized by adding $CaCl_2(0.05{\sim}0.07M)$ at $80{\circ}C$ and $70{\sim}85%$ of the proteins in soy extract and the mixture were preciptated, while only $30{\sim}55%$ of the proteins in whey dialyzed against distilled water were destabilized at the same conditions. Storage stability at $4^{\circ}C$ of the mixture was increased when the mixture was treated at $63^{\circ}C$ and lower temperature.

• Korean Journal of Agricultural Science
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• v.7 no.2
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• pp.190-201
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• 1980

This experiment was designed to optimize the process of manufacturing the soybean cheeses and to elucidate the chemical changes during ripening when the chemical changes during ripening when the milk components and enzyme preparations were added to the raw materials. Conditions for extracting soybean protein such as temperature, duration and amount of water added were determined; various coagulaters were compared by checking the curd texture and yield; starters from S. thermophilus, S. lactis MLB and S. cremoris EB-9 were tested as single- or multi-stain combinations; and the effects of skim milk and/or rennins-both microbial and calf origin-addition upon the process of manufacturing and ripening were studied. The results obtained were as follows. 1. optimal conditions for soybean extraction were found to be: temperature $100^{\circ}C$, duration 10 minutes, and amount of water added 9-fold, as considered the extraction rate of solids and proteins, and curd yield. 2. Sodium gluconate was the most effective among the coagulators tested, and 5% of single-strain starter from S. thermophilus was appered to be adequate inoculum for curd formation. 3. The effects of skim milk and/or rennins addition on the process of manufacturing and ripening of soybean cheeses were: 1) The addition of rennins resulted in fast formation of curd, especially with skim milk it was so. And Hansen rennet extracts brought better results in curd formation than Meito rennet extracts did. 2) No significant effect was observed on the changes in moisture content during ripening, however the levels of moisture contents in the products were higher in case of using Meito rennet extracts. 3) Effect on pH changes during ripening was also not significant in general, while levels of pH were decrease markedly during manufacturing and the initial stage of ripening. 4) The levels of bacterial counts were much higher in case of skim milk addition throughtout the ripening period. In general the numbers were reached to approximately $10^8cells/g$ during manufacturing, then decreased gradually to below $10^2cells/g$ in 8 weeks of ripening. 5) The addition of skim milk and/or rennin resulted in higher ripening index, and skim milk plus Meito rennet extracts was appeared to be best combination for the ripening index.

• Journal of Dairy Science and Biotechnology
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• v.16 no.2
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• pp.98-105
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• 1998

Various peptides derived from food are among the most potent physiologically active agents known, and include anticancer peptides, angiotensin converting enzyme(ACE) inhibitor exhibiting antihypertension action, opioid peptides, antithrombotic peptides, hypocholesterolemic peptides, immunomodulators, calcium absorption enhancers, and other peptides. Hydrophobic peptides extracted from a Cheddar-type cheese slurry were fractionated by gel chromatography and repeated HPLC. A peptide fraction from HPLC showed high cytotoxicity on the tumor cell lines such as a human colon carcinoma, and comprised of Tyr, Ser, Leu, Gly, and others. Hypocholesterolemic peptides were isolated from peptic hydrolyzates of casein and soy proteins. Macropeptides of 1,000${\sim}$5,000 dalton were effective on reducing the cholesterol level of mouse serum. Peptides showing high Krigbaum hydrophobicity and ANS surface hydrophobicity resulted in high hypocholesterolemic effect and fecal steroid concentrations. Caseinomacropeptides(CMP) were isolated from whey powder and treated with soluble and immobilized trypsin to obtain antithrombotic peptides. One fraction from the CMP hydrolyzed with immobilized trypsin for 24h exhibited high antithrombotic activity with 52.5% inhibition of platelet aggregation. These result suggested that peptides from various milk products could be utilized as a good bioactive agents for developing health functional foods.

• Korean Journal of Food Science and Technology
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• v.18 no.5
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• pp.357-363
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• 1986

The thermal conductivity and thermal diffusivity of food are heavity dependent on temperature and composition. The thermal properties of pure component solids were determined by the proposed model at a temperature range of $-40^{\circ}C\;to\;150^{\circ}C$ from the experimental values of 10%, 30% and 60% solid content suspensions. The major components of food products were proteins(albumin, casein, whey protein, meat protein and gluten), lipids (milk fat, vegetable oil, lard and corn oil), carbohydrates (dextrose, lactose, sugar and starch), fibers (cellulose and pectin), all milk salts. A modified probe method was used to measure these properties of pure component suspensions of each major component of food products. General mathematical models which were developed by an optimization technique can be applied to predict the properties of food products.