• Title, Summary, Keyword: enzymes

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The Rumen Ecosystem : As a Fountain Source of Nobel Enzymes - Review -

  • Lee, S.S.;Shin, K.J.;Kim, W.Y.;Ha, J.K.;Han, In K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.6
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    • pp.988-1001
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    • 1999
  • The rumen ecosystem is increasingly being recognized as a promising source of superior polysaccharide-degrading enzymes. They contain a wide array of novel enzymes at the levels of specific activities of 1,184, 1,069, 119, 390, 327 and $946{\mu}mol$ Reducing sugar release/min/mg protein for endoglucanase, xylanase, polygalactouronase, amylase, glucanase and arabinase, respectively. These enzymes are mainly located in the surface of rumen microbes. However, glycoside-degrading enzymes (e.g. glucosidase, fucosidase, xylosidase and arabinofuranosidase, etc.) are mainly located in the rumen fluid, when detected enzyme activities according to the ruminal compartments (e.g. enzymes in whole rumen contents, feed-associated enzymes, microbial cell-associated enzymes, and enzymes in the rumen fluid). Ruminal fungi are the primary contributors to high production of novel enzymes; the bacteria and protozoa also have important functions, but less central roles. The enzyme activities of bacteria, protozoa and fungi were detected 32.26, 19.21 and 47.60 mol glucose release/min/mL mediem for cellulose; 42.56, 14.96 and 64.93 mmol xylose release/min/mL medium after 48h incubation, respectively. The polysachharide-degrading enzyme activity of ruminal anaerobic fungi (e.g. Neocallimastix patriciarum and Piromyces communis, etc.) was much higher approximately 3~6 times than that of aerobic fungi (e.g. Tricoderma reesei, T. viridae and Aspergillus oryzae, etc.) used widely in industrial process. Therefore, the rumen ecosystem could be a growing source of novel enzymes having a tremendous potential for industrial applications.

Impact of Solvent pH on Direct Immobilization of Lysosome-Related Cell Organelle Extracts on TiO2 for Melanin Treatment

  • Bang, Seung Hyuck;Kim, Pil;Oh, Suk-Jung;Kim, Yang-Hoon;Min, Jiho
    • Journal of Microbiology and Biotechnology
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    • v.25 no.5
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    • pp.718-722
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    • 2015
  • Techniques for immobilizing effective enzymes on nanoparticles for stabilization of the activity of free enzymes have been developing as a pharmaceutical field. In this study, we examined the effect of three different pH conditions of phosphate buffer, as a dissolving solvent for lysosomal enzymes, on the direct immobilization of lysosomal enzymes extracted from Hen's egg white and Saccharomyces cerevisiae. Titanium(IV) oxide (TiO2) nanoparticles, which are extensively used in many research fields, were used in this study. The lysosomal enzymes immobilized on TiO2 under each pH condition were evaluated to maintain the specific activity of lysosomal enzymes, so that we can determine the degree of melanin treatment in lysosomal enzymes immobilized on TiO2. We found that the immobilization efficiency and melanin treatment activity in both lysosomal enzymes extracted from Hen's egg white and S. cerevisiae were the highest in an acidic condition of phosphate buffer (pH 4). However, the immobilization efficiency and melanin treatment activity were inversely proportional to the increase in pH under alkaline conditions. In addition, enhanced immobilization efficiency was shown in TiO2 pretreated with a divalent, positively charged ion, Ca2+, and the melanin treatment activity of immobilized lysosomal enzymes on TiO2 pretreated with Ca2+ was also increased. Therefore, this result suggests that the immobilization efficiency and melanin treatment activity of lysosomal enzymes can be enhanced according to the pH conditions of the dissolving solvent.

Inhibitory Effects of Bifidobacterium spp. Isolated from a Healthy Korean on Harmful Enzymes of Human Intestinal Microflora

  • Park, Hye-Young;Bae, Eun-Ah;Han, Myung-Joo;Choi, Eung-Chil;Kim, Dong-Hyun
    • Archives of Pharmacal Research
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    • v.21 no.1
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    • pp.54-61
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    • 1998
  • Five hundreds of bifidobacteria were isolated from a healthy Korean and the inhibitory effects of these isloated bacteria on harmful enzymes of human intestinal microflora were examined by cocultivation of the isolated bifidobacteria with E. coli or total human intestinal microflora. In comparison with the results of E. coli or intestinal microflora cultivation, Bifidobacterium breve K-110, B. breve K-111 and B. infantis K-525 effectively inhibited harmful enzymes ($\beta$-glucuronidase and tryptophanase) of E. coli and lowered the pH of the culture media. Also they inhibited the harmful enzymes ($\beta$-glucosidase, $\beta$-glucuronidase, tryptophanase and urease) and ammonia production of intestinal microflora, and lowered pH of the culture media by increasing lactic acid bacteria of intestinal microflora. When these isolated bifidobacteria were administered on mice, fecal harmful enzymes were also inhibited. Among tested bifidobacteria, B. breve K-110 had the highest inhibitory effect of fecal harmful enzymes.

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Characteristics of Commercial Celluloytic Enzymes (상업용 목질섬유소 분해 효소의 특성)

  • Kim, Young-Yuk;Kim, Chul-Hyun;Park, Soung-Bae;Eom, Tae-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.3
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    • pp.1-8
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    • 2004
  • It is very difficult to compare directly the research results of enzymatic process in pulp and paper industry because commercial enzymes have diversity in its property. The chemical and biological properties of commercial enzymes were Investigated to help comparison of various commercial enzymes each other. In most case, the solid content of liquid enzymes was about 20%. The higher protein content in enzyme product does not mean the higher enzyme activity. Enzymes for paper process should selected by basis of enzyme activity, not by price of enzyme products. The chemical composition of fiber was not so much change with enzyme treatment. The enzymatic hydrolysis of fiber might negligible in paper process.

Lipolytic Enzymes Involved in the Virulence of Human Pathogenic Fungi

  • Park, Minji;Do, Eunsoo;Jung, Won Hee
    • Mycobiology
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    • v.41 no.2
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    • pp.67-72
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    • 2013
  • Pathogenic microbes secrete various enzymes with lipolytic activities to facilitate their survival within the host. Lipolytic enzymes include extracellular lipases and phospholipases, and several lines of evidence have suggested that these enzymes contribute to the virulence of pathogenic fungi. Candida albicans and Cryptococcus neoformans are the most commonly isolated human fungal pathogens, and several biochemical and molecular approaches have identified their extracellular lipolytic enzymes. The role of lipases and phospholipases in the virulence of C. albicans has been extensively studied, and these enzymes have been shown to contribute to C. albicans morphological transition, colonization, cytotoxicity, and penetration to the host. While not much is known about the lipases in C. neoformans, the roles of phospholipases in the dissemination of fungal cells in the host and in signaling pathways have been described. Lipolytic enzymes may also influence the survival of the lipophilic cutaneous pathogenic yeast Malassezia species within the host, and an unusually high number of lipase-coding genes may complement the lipid dependency of this fungus. This review briefly describes the current understanding of the lipolytic enzymes in major human fungal pathogens, namely C. albicans, C. neoformans, and Malassezia spp.

Influence of Supplemental Enzymes, Yeast Culture and Effective Micro-organism Culture on Gut Micro-flora and Nutrient Digestion at Different Parts of the Rabbit Digestive Tract

  • Samarasinghe, K.;Shanmuganathan, T.;Silva, K.F.S.T.;Wenk, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.6
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    • pp.830-835
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    • 2004
  • An experiment of 10 weeks duration was carried out to study the influence of supplemental effective microorganism (EM) culture, yeast culture and enzymes on nutrient digestibility and gut microflora in rabbit gastrointestinal (GI) tract. Twenty four eight to nine weeks old, New Zealand White rabbits were allotted to four dietary treatments; a basal (control) feed, basal feed supplemented with either EM (1%), yeast culture or enzymes (400 ppm). Nutrient flow in digesta and their digestibility at ileum, caecum, colon and in the total tract as well as gut microflora distribution were studied. Feed dry matter was diluted from 92% to about 14% up to the ileum and about 95% of this water was reabsorbed by the colonic rectal segment followed by caecum (25%). EM and yeast improved protein digestibility at a lower rate than enzymes. Ileal, caecal, colonic and total tract digestibility of crude protein with enzymes were higher by 10.8, 9.4, 11.3 and 10.7%, respectively, as compared to the control. Yeast and enzymes increased crude fiber digestibility at ileum, caecum, colon and in the total tract by 8.5, 9.6, 9.0 and 8.3%, respectively, while EM improved them at a lower rate. Irrespective of treatments, total tract digestibility of crude protein (0.698-0.773) and fiber (0.169-0.183) were greater (p<0.05) than the ileal digestibility. Even though a post-caecal protein digestibility was observed, fiber digestion seemed to be completed in the caecum especially with yeast and enzymes. High precaecal digestibility of crude fiber (97%) and protein (95%) were observed even without additives probably due to caecotrophy. EM and yeast culture promoted the growth of lactic acid bacteria especially in the caecum but they did not influence gut yeast and mould. Present findings reveal that even though rabbits digest nutrients efficiently through hind gut fermentation, they can be further enhanced by EM, yeast and enzymes. Of the three additives tested, enzymes found to be the best.

Overproduction of Lactic Bacterial Enzymes and Bioactive Components

  • Lee, Byong-H.
    • 한국유가공학회:학술대회논문집
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    • pp.45-55
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    • 2002
  • Recent developments in the application of molecular biology to food grade lactic acid bacteria (LAB) have shown that it could be feasible to engineer metabolic pathways to either enhance specific metabolic fluxes or to divert metabolites for the production of different or new end products. This engineering requires detailed knowledge of enzymes involved in metabolism and regulation within the targeted organism but little works have been done in this area. During biochemical and molecular characterisation of lactic bacterial enzymes, some of probiotic Lactobacillus and Bifidobacterium species were found to be very useful for food, nutraceutical and pharmaceutical industries. The enzymes are usually intracellular and the yields are very low to be useful for industrial applications. Among many enzymes and proteins of lactic bacteria studied, some of our gene cloning achievements have contributed to overproduction of lactic bacterial enzymes such as peptidases, esterases, lactases, bile salt hydrolases and linoleate isomerases for foods and nutraceuticals.

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Industrial applications and characteristics of lignocellulolytic enzymes in Basidiomycetous fungi (담자균류 목질섬유소 분해효소의 특성과 산업적 이용)

  • Lim, Sun-Hwa;Kang, Hee-Wan
    • Journal of Mushroom
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    • v.14 no.2
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    • pp.51-58
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    • 2016
  • Basidiomycetous fungi are one of the most potent biodegraders because many of its species grow on dead wood or litter, in environments rich in lignocellulose. For the degradation of lignocellulose, basidiomycetes utilize their lignocellulytic enzymes, which typically include laccase (EC 1.10.3.2), lignin peroxidase (EC 1.11.1.14), xylanase (EC 3.2.1.8), and cellulase (EC 3.2.1.4). In recent years, the practical applications of basidiomycetes have ranged from the textile to the pulp and paper industries, and from food applications to bioremediation processes and industrial enzymatic saccharification of biomass. Recently, spent mushroom substrates of edible mushrooms have been used as sources of bulk enzymes to decolorize synthetic dyes in textile wastewater. In this review, the occurrence, mode of action, general properties, and production of lignocellulytic enzymes from mushroom species will be discussed. We will also discuss the potential applications of these enzymes.

A Stereochemical Aspect of Pyridoxal 5' -Phosphate Dependent Enzyme Reactions and Molecular Evolution

  • Jhee, Kwang-Hwan;Tohru, Yoshimura;Yoichi, Kurokawa;Nobuyoshi, Esaki;Kenji, Soda
    • Journal of Microbiology and Biotechnology
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    • v.9 no.6
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    • pp.695-703
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    • 1999
  • We have studied the stereospecificities of various pyridoxal 5'-phosphate (PLP) dependent enzymes for the hydrogen transfer between the C-4' of a bound coenzyme and the C-2 of a substrate in the transamination catalyzed by the enzymes. Stereospecificities reflect the structures of enzyme active-sites, in particular the geometrical relationship between the coenzyme-substrate Schiff base and the active site base participating in an $\alpha$-hydrogen abstraction. The PLP enzymes studied so far catalyze only a si-face specific (pro-S) hydrogen transfer. This stereochemical finding suggests that the PLP enzymes have the same topological active-site structures, and that the PLP enzymes have evolved divergently from a common ancestral protein. However, we found that o-amino acid aminotransferase, branched chain L-amino acid aminotransferase, and 4-amino-4-deoxychorismate lyase, which have significant sequence homology with one another, catalyze a re-face specific (pro-R) hydrogen transfer. We also showed that PLP-dependent amino acid racemases, which have no sequence homology with any aminotransferases, catalyze a non-stereospecific hydrogen transfer: the hydrogen transfer occurs on both faces of the planar intermediate. Crystallographical studies have shown that the catalytic base is situated on the re-face of the C-4' of the bound coenzyme in o-amino acid aminotransferase and branched chain L-amino acid aminotransferase, whereas the catalytic base is situated on the si-face in other aminotransferases (such as L-aspartate aminotransferase) catalyzing the si-face hydrogen transfer. Thus, we have clarified the stereospecificities of PLP enzymes in relation with the primary structures and three-dimensional structures of the enzymes. The characteristic stereospecificities of these enzymes for the hydrogen transfer suggest the convergent evolution of PLP enzymes.

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Binding Pattern Elucidation of NNK and NNAL Cigarette Smoke Carcinogens with NER Pathway Enzymes: an Onco-Informatics Study

  • Jamal, Qazi Mohammad Sajid;Dhasmana, Anupam;Lohani, Mohtashim;Firdaus, Sumbul;Ansari, Md Yousuf;Sahoo, Ganesh Chandra;Haque, Shafiul
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.13
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    • pp.5311-5317
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    • 2015
  • Cigarette smoke derivatives like NNK (4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone) and NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butan-1-ol) are well-known carcinogens. We analyzed the interaction of enzymes involved in the NER (nucleotide excision repair) pathway with ligands (NNK and NNAL). Binding was characterized for the enzymes sharing equivalent or better interaction as compared to +Ve control. The highest obtained docking energy between NNK and enzymes RAD23A, CCNH, CDK7, and CETN2 were -7.13 kcal/mol, -7.27 kcal/mol, -8.05 kcal/mol and -7.58 kcal/mol respectively. Similarly the highest obtained docking energy between NNAL and enzymes RAD23A, CCNH, CDK7, and CETN2 were -7.46 kcal/mol, -7.94 kcal/mol, -7.83 kcal/mol and -7.67 kcal/mol respectively. In order to find out the effect of NNK and NNAL on enzymes involved in the NER pathway applying protein-protein interaction and protein-complex (i.e. enzymes docked with NNK/NNAL) interaction analysis. It was found that carcinogens are well capable to reduce the normal functioning of genes like RAD23A (HR23A), CCNH, CDK7 and CETN2. In silico analysis indicated loss of functions of these genes and their corresponding enzymes, which possibly might be a cause for alteration of DNA repair pathways leading to damage buildup and finally contributing to cancer formation.