• Fisheries and Aquatic Sciences
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• v.21 no.5
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• pp.13.1-13.8
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• 2018

Amyloid plaque, also called senile plaque, the product of aggregation of ${\beta}$-amyloid peptides ($A{\beta}$), is observed in brains of the patients with Alzheimer's disease (AD) and is one of the key factors in etiology of the disease. In this study, hydrolysates obtained from the sea hare (Aplysia kurodai) were investigated for ${\beta}$-secretase inhibitory peptide. The sea hare's muscle protein was hydrolyzed using six enzymes in a batch reactor. Trypsin hydrolysate had highest ${\beta}$-secretase inhibitory activity compared to the other hydrolysates. ${\beta}$-secretase inhibitory peptide was separated using Sephadex G-25 column chromatography and high-performance liquid chromatography on a C18 column. ${\beta}$-secretase inhibitory peptide was identified as eight amino acid residues of Val-Ala-Ala-Leu-Met-Leu-Phe-Asn by N-terminal amino acid sequence analysis. $IC_{50}$ value of purified ${\beta}$-secretase inhibitory peptide was $74.25{\mu}M$, and Lineweaver-Burk plots suggested that the peptide purified from sea hare muscle protein acts as a competitive inhibitor against ${\beta}$-secretase. Results of this study suggest that peptides derived from sea hare muscle may be beneficial as anti-dementia compounds in functional foods or as pharmaceuticals.

• Korean Journal of Agricultural Science
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• v.41 no.2
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• pp.141-147
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• 2014

Diacylglycerol-oil (DAG oil) and four kinds of fatty acids [C16:0, C18:0, perillar oil-hydrolyzate(C18:3, 59.7%) and docosahexaenoic acid(DHA, C22:6, 63.7%)] were enzymatically esterified with 1:0.5, 1:1 and 1:1.5 molar ratio (DAG oil: fatty acids) to produce structured DAG. The reaction mixture were catalyzed by addition of sn-1,3 specific Lipozyme RMIM with 10 wt% of total substrates, and reacted for 1, 3, 6 and 24 hr at $62^{\circ}C$ with 220 rpm on the shaking water bath. The produced DAG were analyzed by TLC. In the result, the proportion of each fatty acid [(C16:0, C18:0, perilla oil-hydrolysate(C18:3, 59.7%) and DHA(C22:6, 63.7%)] on DAG products were increased as molar ratios of substrate increased. Among them, DHA showed the least reaction rate in which 24.2 % of DHA was found in the structured DAG molecules after 24 hr reaction with 1:1.5 molar substrate amount ratio.

• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.97-102
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• 2009

In order to obtain a non-toxic and more active and stable microorganism-produced tyrosinase inhibitor, we isolated actinomycetes F-97, a producer of tyrosinase inhibitor, from soil. The aerial hyphae of this strain were gray in color with tree types. Under the microscopic examination, the isolate formed a spiral aerial spore mass with a smooth surface. The analysis of cell wall acid hydrolysate of the isolate revealed the presence of LL-diaminopimelic acid(LL-DAP). No specific sugar was detected. From these results and the cultural and physiological characteristics described in the Bergey's Manual, actinomycetes F-97 was identificated as, or best-matched to, Streptomyces aburaviensis.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1791-1800
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• 2004

Angiotensin I, a model decapeptide, was glycosylated and partially hydrolyzed with HCl (6 N, 80 $^{\circ}C$, 4 h), aminopeptidase, and carboxypeptidase Y. A single peptide mass map obtained from truncated peptides in the partial acid hydrolysate of angiotensin and its glycosylation product mixture by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry enabled sequencing of angiotensin by a combinatorial procedure. MALDI-TOF and electrospray ionization (ESI) tandem mass spectrometric results indicate that both the N-terminal amino group of aspartic acid and the guanidinium group of the second residue arginine are glycosylated.

• Mycobiology
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• v.32 no.4
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• pp.170-172
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• 2004

The efficiency of acid, enzyme and microbial pretreatment of rice bran was compared based on the content of cellulose, hemicellulose, reducing sugars and xylose in the substrate. An isolate of Aspergillus niger or a strain of Trichoderma viride(MTCC 800) was employed for microbial pretreatment of rice bran in solid state. Acid pretreatment resulted in the highest amount of reducing sugars followed by enzyme and microbial pretreatment. A. niger showed a higher rate of hydrolysis than T. viride. The rice bran hydrolysate obtained from the different methods was subsequently fermented to ethanol either by Zymomonas mobilis(NCIM 806) or by Pichia stipitis(NCIM 3497). P. stipitis fermentation resulted in higher ethanol(37% higher) and biomass production($76{\sim}83%$ higher) than those of Z. mobilis. Maximum ethanol production resulted at 12h in Zymomonas fermentation, while in Pichia fermentation, it was observed at 60h. Microbial pretreatment of rice bran by A. niger followed by fermentation employing P. stipitis was more efficient but slower than the other microbial pretreatment and fermentation.

• Journal of Microbiology and Biotechnology
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• v.32 no.11
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• pp.1479-1484
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• 2022

Bacterial cellulose (BC) is gaining attention as a carbon-neutral alternative to plant cellulose, and as a means to prevent deforestation and achieve a carbon-neutral society. However, the high cost of fermentation media for BC production is a barrier to its industrialization. In this study, chestnut shell (CS) hydrolysates were used as a carbon source for the BC-producing bacteria strain, Gluconacetobacter xylinus ATCC 53524. To evaluate the suitability of the CS hydrolysates, major inhibitors in the hydrolysates were analyzed, and BC production was profiled during fermentation. CS hydrolysates (40 g glucose/l) contained 1.9 g/l acetic acid when applied directly to the main medium. As a result, the BC concentration at 96 h using the control group and CS hydrolysates was 12.5 g/l and 16.7 g/l, respectively (1.3-fold improved). In addition, the surface morphology of BC derived from CS hydrolysates revealed more densely packed nanofibrils than the control group. In the microbial BC production using CS, the hydrolysate had no inhibitory effect during fermentation, suggesting it is a suitable feedstock for a sustainable and eco-friendly biorefinery. To the best of our knowledge, this is the first study to valorize CS by utilizing it in BC production.

• Food Science and Preservation
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• v.30 no.3
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• pp.434-445
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• 2023

Hemp (Cannabis sativa L.) seeds have recently been attracting attention as a new high-value-added food material owing to their excellent nutritional properties, and research on the development of functional food materials using hemp seeds is actively progressing. This study aimed to evaluate the antioxidant properties of hemp seed protein hydrolysates. Protein hydrolysates were prepared from defatted hemp seed powder (HS) by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain). 2,4,6-trinitrobenzene sulfonic acid (TNBS) assay and SDS-PAGE analysis revealed that HS showed a high degree of hydrolysis after treatment with each enzyme except papain. The total polyphenol content of the protein hydrolysates (<3 kDa) and the RC50 values obtained from two different antioxidant tests showed that alcalase hydrolysate (HSA) had a relatively high level of antioxidant capacity. In addition, treatment with HSA (25-100 ㎍/mL) significantly inhibited linoleic acid peroxidation. These results suggest that hemp seed protein hydrolysates are potential sources of natural antioxidants. Future studies will focus on the identification of active peptides from HSA.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.136-141
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• 2009

Biological activities of enzymatic hydrolysate of spirulina (EHS) were investigated. EHS showed no significant effects on the growth-stimulating activity for lactic-acid bacteria and antioxidant activity. EHS showed slight in vitro growth-inhibitory effects (15% at 1.42 mg/L) on a human cervical cancer cell line (HeLa). In addition, the anticoagulant activities of EHS were measured based on three different pathways: common, intrinsic and extrinsic pathways. As an indication of anticoagulant activity on common pathway, thrombin time (TT) of EHS (100 mg/L) was measured as 155.6 sec. Activated partial thromboplastin time (aPTT) for intrinsic pathway of EHS (1,000 mg/L) was measured as 95.8 sec. Prothrombin time (PT) based on extrinsic pathway of EHS (1,000 mg/L) was measured as 10.6 sec. These data showed that EHS have influences on anticoagulant factors of common pathway and intrinsic pathway. Consequently it was found that EHS could be used as a functional food for blood circulation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.2
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• pp.69-76
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• 2006

To optimize tissue culture responses for genetic transformation of Kentucky bluegrass, the effects of culture medium supplements on tissue culture responses were investigated with mature seeds of a cultivar 'Newport' as explant tissues. The optimal concentration of 2,4-D (2.4-dichloro phenoxy acetic acid) for the induction of embryogenic callus from mature seed was 3 mg/L. Plant regeneration frequency was 54% when embryogenic callus was cultured on the regeneration medium supplemented with 1 mg/L 2,4-D and 3 mg/L of BA (6-benzyladenine). Addition of 1 g/L of casein hydrolysate and 500 mg/L of L-proline improved frequencies of embryogenic callus induction and plant regeneration up to 60.8% and 58.3%, respectively. Regenerated plants were grown normally when shoots transplanted to the soil. A rapid and efficient plant regeneration system established in this study. We suggest that the results may be useful for molecular breeding of Kentucky bluegrass through genetic transformation.