• Title/Summary/Keyword: enzymatic properties.

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Deinking of Electrostatic Wastepaper with Cellulolytic Enzymes and Surfactant in Neutral pH

  • Eom, Tae-Jin;Yoon, Kyong-Dong;Park, Soung-Bae
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06a
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    • pp.123-128
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    • 2006
  • Enzymatic deinking method can avoids the alkaline environment as usual required in chemical deinking, which consequently cuts chemical costs and reduced the white water pollution. The electrostatic wastepaper was dinked with commercial cellulolytic enzymes and surfactant in neutral pH and the effectiveness of deinking and the physical properties of deinked pulp were evaluated. The disintegrating efficiency of the electrostatic wastepaper in neutral pH was enhanced with enzyme treatments. Although the freeness of deinked pulp with enzymes was higher than that of deinked pulp with chemical deinking agents, the brightness of the enzymatic deinked pulp was slightly lower than that of the chemical deinked pulp. But, by additions of nonionic surfactants, the brightness of deinked pulp was increased with less residual ink particles and mechanical properties of enzymatic deinked pulp was improved compared to the deinked pulp of conventional alkaline method.

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Deinking of Electrostatic Wastepaper with Cellulolytic Enzymes and Surfactant in Neutral pH

  • Eom, Tae-Jin;Kim, Kang-Jae;Yoon, Kyoung-Dong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.5
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    • pp.12-19
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    • 2007
  • Enzymatic deinking method can avoids the alkaline environment as usual required in chemical deinking, which consequently cuts chemical costs and reduced the white water pollution. The electrostatic wastepaper was dinked with commercial cellulolytic enzymes and surfactant in neutral pH and the effectiveness of deinking and the physical properties of deinked pulp were evaluated. The disintegrating efficiency of the electrostatic wastepaper in neutral pH was enhanced with enzyme treatments. Although the freeness of deinked pulp with enzymes was higher than that of deinked pulp with chemical de inking agents, the brightness of the enzymatic deinked pulp was slightly lower than that of the chemical deinked pulp. But, by additions of nonionic surfactants, the brightness of deinked pulp was increased with less residual ink particles and mechanical properties of enzymatic deinked pulp was improved compared to the deinked pulp of conventional alkaline method.

Enzymatic preparation and antioxidant activities of protein hydrolysates from hemp (Cannabis sativa L.) seeds

  • Hyeon-Ji Yoon;Gyu-Hyeon Park;Yu-Rim Lee;Jeong-Min Lee;Hyun-Lim Ahn;Syng-Ook Lee
    • 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.

Enzymatic Deinking of Old Newsprit with Alkalophilic Enzymes from Coprinus cinereus 2249

  • Lee, Jung-Myong;Eom, Tae-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.5
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    • pp.12-17
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    • 1999
  • This study was to evaluate applications of the alkalophilic enzymes from Coprinus cinereus 2249 with old newsprint(ONP). A enzymatic deinking process based on alkalopholic enzymes was investigated . It was found that alkalophilic enzymes could effectively deink old newsprint. When applied on deinking of the old newsprint, it increases the freeness and brightness due to effect of hydrolysis at 0.1% enzyme concentration . Also, the physical properties of deinked pulp were improved.

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Synthesis of Aesculetin and Aesculin Glycosides Using Engineered Escherichia coli Expressing Neisseria polysaccharea Amylosucrase

  • Park, Soyoon;Moon, Keumok;Park, Cheon-Seok;Jung, Dong-Hyun;Cha, Jaeho
    • Journal of Microbiology and Biotechnology
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    • v.28 no.4
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    • pp.566-570
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    • 2018
  • Because glycosylation of aesculetin and its 6-glucoside, aesculin, enhances their biological activities and physicochemical properties, whole-cell biotransformation and enzymatic synthesis methodologies using Neisseria polysaccharea amylosucrase were compared to determine the optimal production method for glycoside derivatives. High-performance liquid chromatography analysis of reaction products revealed two glycosylated products (AGG1 and AGG2) when aesculin was used as an acceptor, and three products (AG1, AG2, and AG3) when using aesculetin. The whole-cell biotransformation production yields of the major transfer products for each acceptor (AGG1 and AG1) were 85% and 25%, respectively, compared with 68% and 14% for enzymatic synthesis. These results indicate that whole-cell biotransformation is more efficient than enzymatic synthesis for the production of glycoside derivatives.

Screening of Microorganisms Secreted High Efficient Enzymes and Properties of Enzymatic Deinking for Old Newsprint(II) - Isolation and screening of fungi producing cellulase and xylanase- (고효율 효소를 분비하는 균주의 선발 및 신문고지의 효소탈묵 특성(제2보) -Cellulase와 Xylanase를 생산하는 Fungi의 분리 및 선발-)

  • Park Seong-Cheol;Kang Jin-Ha;Lee Yang-Soo
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.3
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    • pp.9-14
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    • 2004
  • The useful fungi which secret extracellular enzymes was selected for deinking agent of old newsprint. Five fungal strains were isolated from a paper mill soil ground. The CMCase, FPase and xylanase activities of fungi on the liquid culture were investigated at optimal growth conditions. The results of this study were as follow: The optimal pH and temperature for culture growth were 4~8 and 27~$35^{\circ}C$, respectively. For screening of extracellular enzymes at optimal culture conditions the optimal culture period were less than 6-7 days. Fusarium pallidoroseum and Aspergiilus niger which shows relatively higher CMCase, FPase and xylanase activities than the other species were selected for further enzymatic deinking research.

Studies on Enzymes of the Higher Fungi of Korea(IV) -Isolation and Enzymatic Properties of Cellulase from Wild Cryptoderma citrinum- (한국산(韓國産) 고등균류(高等菌類)의 효소(酵素)에 관한 연구(硏究)(IV) -야생(野生) 기와층버섯의 섬유소분해효소(纖維素分解酵素)의 분리(分離) 및 효소학적(酵素學的) 성질(性質)-)

  • Park, Wan-Hee
    • Korean Journal of Pharmacognosy
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    • v.19 no.1
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    • pp.28-33
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    • 1988
  • To identify biologically active enzymatic components of the higher fungi in Korea, the dried carpophores of Cryptoderma citrinum was smashed with cool distilled water, extracted, salted out and the precipitate was purified by dialysing with visking tube and dissolved with pH 7.8 ammonia aqua. The fraction of the filtrate was lyophilized to obtain as light brown powder and then cellulase activity was determined. Cellulolytic potency of Cryptoderma citrinum was 750 unit/g. The optimum condition for the enzymatic reaction was pH 4.5 and $40^{\circ}$. The enzyme activity was activated in the presence of $Ca^{2+}$, $Fe^{2+}$ and $Co^{2+}$.

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Enzymatic synthesis of cephalexin

  • Rhee, D.K.;Rhee, J.S.;Ryu, D.Y.
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1978.10a
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    • pp.206.4-206
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    • 1978
  • By utilizillg whole cell enzyme of the Xantho-monas citri IFO 3835, cephalexin is synthesized directly from 7-amino-deacetoxy cephalosporanic acid (7-ADCA) and phenyl glycine methyl ester (PGM). To date, cephalexin has been manufactu-red by chemical process involving fairly large number of steps to protect the amino group of phenly glycine and carboxyl group of 7-ADCA. However, the enzymatic process involves only a single step with 85% conversion in 90 minutes. The fermentation variables studied indicate that oxygen transfer is limiting step in the enzyme production. Optimum conditions for enzymatic reaction were 37 C, pH 6.0, and the optimum substrate molar ratio of PGM to 7-ADCA was 2. Other variables that are related to the biochemical properties of whole cell enzyme temperature stability, pH stability, kinetic constants, reusing effect, enzyme loading effect were also evaluated.

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Cellular Biomarker of Membrane Stability and Hydrolytic Enzyme Activity in the Hemocytes of Benzo(a)pyrene-exposed Pacific oyster, Crassostrea gigas

  • Jo Qtae;Choy Eun-Jung;Park Doo Won;Jee Young-Ju;Kim Sung Yeon;Kim Yoon
    • Fisheries and Aquatic Sciences
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    • v.5 no.4
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    • pp.263-270
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    • 2002
  • The Pacific oysters, Crassostrea gigas, were stressed with different concentrations of benzo(a) pyrene and depurated to determine the hemocyte lysosomal membrane stability and hydrolytic enzymatic activity as a biomarker candidate to the chemical, using NRR (neutral red retention) and API ZYM System, respectively. The membrane damage measured as NRR decrease was significant with the increase of chemical concentration and exposure time (P<0.05), providing a possible tool for biomarker. Interestingly, the control showed intrinsic stress probably due to captive life in the laboratory, and a recovering trend was also found during the depuration. The benzo(a)pyrene-exposed oysters showed increased enzyme activities in alkaline phosphatase, esterase (C4), acid phosphatase, naphthol-AS-BI-phospho­hydrolase, $\beta$-galactosidase, $\beta$-glucuronidase, and N-acetyl- $\beta$-glucosaminidase. Of them, only two enzymes, acid phosphatase and alkaline phosphatase, showed some potential available for the generation of enzymatic biomarker in the oyster. The results are suggestive of the potential availability of the cellular and enzymatic properties as a biomarker. However, considering that a robust biomarker should be insensitive to natural stress coming from normal physiological variation, but sensitive to pollutants, a concept of intrinsic stress the animal possesses should be taken into consideration. This reflects the necessity of further research on the intrinsic stress affecting the cellular and enzymatic properties of the chemical­stressed oysters prior to using the data as a biomarker.

Improving the Functional Properties of Oyster Hydrolysates by Two-step Enzymatic Hydrolysis (2단 가수분해에 의한 굴 가수분해물의 기능성 개선)

  • Chung In-Kwon;Kim Jin-Soo;Heu Min-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.39 no.3
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    • pp.269-277
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    • 2006
  • This study prepared functional oyster hydrolysates using two-step enzymatic hydrolysis and investigated their functional properties. To prepare two-step enzymatic hydrolysates (TSEH), oysters were hydrolyzed using 1% Protamex (PR) at $40^{\circ}C$ and pH 6.0 for 1 hr before sequential treatment with one of the following enzymes for 1 hr: Alcalase (AL), Flavourzyme (FL), Neutrase (NE), pepsin (PE), and trypsin (TR). The PRAL, PRNE and PRTR hydrolysates had significantly greater angiotensin I converting enzyme (ACE) inhibitory activity than did PR and the other TSEHs. Only the antioxidant activity of the PRNE hydrolysate was significantly different (p<0.05), while none of the TSEHs had antimicrobial activity. The oyster hydrolysate prepared by sequential treatment with Protamex and Neutrase (PRNE) had the best ACE inhibitory activity and antioxidant activity, with $IC_{50}$ values of 0.40 and 0.94 mg/mL, respectively. The PRNE hydrolysate was processed through an ultrafiltration (UF) series with molecular weight cut-off (MWCO) membranes of 3, 5, 10, and 30 kDa, and the ACE inhibitory, antioxidant, and antimicrobial activities of the permeates were determined. The permeate through the 3-kDa MWCO membrane had greater ACE inhibitory activity and antioxidant activity than did the other PRNE permeates, with $IC_{50}$ values of 0.11 and 0.40 mg/mL, respectively.