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Modification of the characteristics of silkworm powder by treatment with alkaline protease
( Sungkuk Kim ),( Youyoung Jo ),( Kwanggill Lee ),( Hyunbok Kim ),( Yongsoon Kim ),( Wantaek Ju ),( Daeun Jung ),( Haeyong Kweon ) 한국잠사학회 2015 International Journal of Industrial Entomology Vol.31 No.1
Enzymatic modification of proteins is often used to increase the biological activity of materials. Silkworm powder has been investigated as a functional food resource, but no study has been performed on its modification by commercial food enzyme. Therefore, this study aimed to determine the feasibility of such modification of silkworm powder by alkaline protease. The activity of the enzyme was confirmed using an azocasein assay. Subsequently the silkworm powder was hydrolyzed by enzymatic treatment. UV visible spectrometry showed that the supernatant of silkworm powder subjected to enzymatic treatment had a stronger absorption band than the untreated powder. SDS-PAGE electrophoresis showed that the molecular weight of silkworm powder decreased on enzymatic treatment. Thus the results indicate that commercial enzymes might be used to modify the characteristics of silkworm powder.
Preparation, structure, and properties of cellulose nanofibril/silk sericin composite film
( Mijin Jang ),( Byungdae Park ),( Haeyong Kweon ),( Youyoung Jo ),( Inchul Um ) 한국잠사학회 2015 International Journal of Industrial Entomology Vol.31 No.1
Recently, sericin has attracted increasing attention in biomedical and cosmetic research because of its useful properties including acceleration of wound healing, improvement of cell attachment, and inhibition of ultraviolet-B induced apoptosis. However, sericin films have poor mechanical properties, which restricts the application to those fields. In this study, cellulose nanofibril (CNF)/sericin composite films were fabricated by solvent casting, and the effects of ultrasonication time and CNF content on the solution turbidity, molecular conformation, and film mechanical properties of sericin film were examined. As the ultrasonication time increased, the turbidity of the CNF/sericin suspension decreased. Conversely, as the CNF content increased, the turbidity increased. However, b-sheet crystallization and mechanical properties remained almost unchanged by varying the ultrasonication time and CNF content, indicating that CNF is not effective to improve the mechanical properties of sericin films.
SangMi Han,KwangGill Lee,JooHong Yeo,SoonOk Woo,HaeYong Kweon,YouYoung Jo,Peter Molan 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.05
Since the ancient times the therapeutic application of honeybee venom (BV) is practised and persisted until the present days. Resistant bacteria are in emergence and some drugs no longer have an antimicrobial action. To purify the melittin known as antibacterial peptide, five major peptidergic subfractions were separated, purified and identified from the whole BV. We investigated the antibacterial activity of whole BV and purified melittin against Staphylococcus aureus by the minimum inhibitory concentrations (MIC) and the postantibiotic effect (PAE). The MIC of whole BV for S. aureus was 0.06 ㎍/㎖, respectively. The MIC of melittin was 0.06 ㎍/㎖ on S. aureus. The in vitro PAE of whole BV and isolated melittin were determined using E. coli and S. aureus. The PAE of whole BV against S. aureus were 3.45 h (1×MIC). The PAE of melittin against S. aureus was 4.35 h (1 × MIC). Also both whole BV and melittin killed S. aureus at 5 × MIC. The regrowth wasn't observed after 18 h. These results suggest that whole BV and melittin will be developed a novel antibacterial drug.
( Jun Sik Eom ),( Shin Ja Lee ),( Hyun Sang Kim ),( Youyoung Choi ),( Seong Uk Jo ),( Sang Suk Lee ),( Eun Tae Kim ),( Sung Sill Lee ) 한국축산학회 2022 한국축산학회지 Vol.64 No.2
Ketosis is associated with high milk yield during lactating or insufficient feed intake in lactating dairy cows. However, few studies have been conducted on the metabolomics of ketosis in Korean lactating dairy cows. The present study aimed to investigate the serum and urine metabolites profiling of lactating dairy cows through proton nuclear magnetic resonance (<sup>1</sup>H-NMR) spectroscopy and comparing those between healthy (CON) and subclinical ketosis (SCK) groups. Six lactating dairy cows were categorized into CON and SCK groups. All experimental Holstein cows were fed total mixed ration. Serum and urine samples were collected from the jugular vein of the neck and by hand sweeping the perineum, respectively. The metabolites in the serum and urine were determined using <sup>1</sup>H-NMR spectroscopy. Identification and quantification of metabolites was performed by Chenomx NMR Suite 8.4 software. Metabolites statistical analysis was performed by Metaboanalyst version 5.0 program. In the serum, the acetoacetate level was significantly (p < 0.05) higher in the SCK group than in the CON group, and whereas acetate, galactose and pyruvate levels tended to be higher. CON group had significantly (p < 0.05) higher levels of 5-aminolevulinate and betaine. Indole-3-acetate, theophylline, p-cresol, 3-hydroxymandelate, gentisate, N-acetylglucosamine, N-nitrosodimethylamine, xanthine and pyridoxine levels were significantly (p < 0.05) higher in the urine of the SCK group than that in the CON group, which had higher levels of homogentisate, ribose, gluconate, ethylene glycol, maltose, 3-methyl-2-oxovalerate and glycocholate. Some significantly (p < 0.05) different metabolites in the serum and urine were associated with ketosis diseases, inflammation, energy balance and body weight. This study will be contributed useful a future ketosis metabolomics studies in Korea.
Hyun Sang Kim,Jun Sik Eom,Shin Ja Lee,Youyoung Choi,Seong Uk Jo,Sang Suk Lee,Eun Tae Kim,Sung Sill Lee Asian Australasian Association of Animal Productio 2023 Animal Bioscience Vol.36 No.8
Objective: The purpose of this study was to perform a comparative analysis of metabolite levels in serum and milk obtained from cows fed on different concentrate to forage feed ratios. Methods: Eight lactating Holstein cows were divided into two groups: a high forage ratio diet (HF; 80% Italian ryegrass and 20% concentrate of daily intake of dry matter) group and a high concentrate diet (HC; 20% Italian ryegrass and 80% concentrate) group. Blood was collected from the jugular vein, and milk was sampled using a milking machine. Metabolite levels in serum and milk were estimated using proton nuclear magnetic resonance and subjected to qualitative and quantitative analyses performed using Chenomx 8.4. For statistical analysis, Student's t-test and multivariate analysis were performed using Metaboanalyst 4.0. Results: In the principal component analysis, a clear distinction between the two groups regarding milk metabolites while serum metabolites were shown in similar. In serum, 95 metabolites were identified, and 13 metabolites (include leucine, lactulose, glucose, betaine, etc.) showed significant differences between the two groups. In milk, 122 metabolites were identified, and 20 metabolites (include urea, carnitine, acetate, butyrate, arabinitol, etc.) showed significant differences. Conclusion: Our results show that different concentrate to forage feed ratios impact the metabolite levels in the serum and milk of lactating Holstein cows. A higher number of metabolites in milk, including those associated with milk fat synthesis and the presence of Escherichia coli in the rumen, differed between the two groups compared to that in the serum. The results of this study provide a useful insight into the metabolites associated with different concentrate to forge feed ratios in cows and may aid in the search for potential biomarkers for subacute ruminal acidosis.