Characterization and evaluation of fungal enzymatic pool with unhairing activity / B. C. Galarza in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 100, N° 5 (09-10/2016)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 100, N° 5 (09-10/2016) . - p. 257-262 Titre : Characterization and evaluation of fungal enzymatic pool with unhairing activity Type de document : texte imprimé Auteurs : B. C. Galarza, Auteur ; M. Garro, Auteur ; J. Martegani, Auteur ; R. Hours, Auteur Année de publication : 2016 Article en page(s) : p. 257-262 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Caractérisation Cuirs et peaux -- Analyse Cuirs et peaux de bovins Enzymes fongiques Enzymes protéolytiques Une enzyme protéolytique est une enzyme capable de couper une protéine en plusieurs fragments ou peptides. La trypsine, la papaïne, la pepsine, la chymotrypsine, la plasmine, la subtilisine... sont capables de couper une protéine, chaque enzyme étant spécifique de certains sites particuliers de cette protéine. C'est ainsi, par exemple, qu'une immunoglobuline G est découpée par la papaïne en un fragment Fc et deux fragments Fab, comme l'a montré Porter en 1959. Epilage enzymatique Microscopie électronique à balayage Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The use of enzymes in the leather industry in the beamhouse area to partially replace sulfide, can reduce to almost 50% the H2S emission. In this enzyme treatment proteolysis needs to be controlled to prevent the extension of activity to collagen. Collagen must keep its optimal conditions for the tannage process and to give high quality leather. In this sense it is necessary to characterize the enzyme from the physicochemical point of view and to study the morphological changes produced in bovine skin to control its action. An enzymatic pool of geophilic strain Trichophyton ajelloi cultured in solid media was characterized. Azocaseinolytic and keratinolytic activity was determined under different conditions. The enzymatic pool showed tolerance to high T°, optimal pH9 in bath substrates, partial inhibition in concentrations 0.1M, 0.01M and 0.001 M from metallic salts (Ca Cl2, BaCl2, KCl, CuSO4), activation by NaCl, reducing agents as Na2S03, Na2S, L-cystein hydrochloride monohydrate, thioglycolic acid and commercial anionic and non-ionic surfactants (SDS, isogràs AN, Triton, Baymol, Azymol). Inactivation exerted by. PMSF showed a serine-protease as a component of the pool (MEROPS system). When the enzymatic pool was applied for 24-48 hours under optimal conditions on bovine skin pieces, a depilatory affect was observed. The changes in the bovine skin morphology were observed by SEM, alter fixation in formaldehyde and dehydration with alcohol as part of a tentative protocol for bovine skin analysis by SEM (Scanning Electron Microscopy). Note de contenu : - Solid-state culture - Characterization of crude extract - Test procedures - SEM : sample preparation and observation En ligne : https://drive.google.com/file/d/1Cn1wPo2dkSvZQZ62tGJGbpyJQQ1Ylr7Q/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27091 [article]

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Collagen hydrolysate : Soluble skin applied in post-tanning processes : Part 2 - Interaction with acyrlic retanning agents / Carlos S. Cantera in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 86, N° 5 (09-10/2002)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 86, N° 5 (09-10/2002) . - p. 195-202 Titre : Collagen hydrolysate : Soluble skin applied in post-tanning processes : Part 2 - Interaction with acyrlic retanning agents Type de document : texte imprimé Auteurs : Carlos S. Cantera, Auteur ; J. Martegani, Auteur ; G. Esterelles, Auteur ; Jorge A. Vergara, Auteur Année de publication : 2002 Article en page(s) : p. 195-202 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : acrylique, Acide L'acide acrylique ou acide acroléïque ou acide prop-2-énoïque est un composé organique de formule brute C3H4O2 et de formule semi-développée CH2=CHCOOH. C'est un acide carboxylique et un alcène vinylique, et se présente comme un liquide incolore à l'odeur âcre. L'acide acrylique et ses esters, les acrylates, sont utilisés dans la fabrication de matières plastiques, dans les peintures acryliques et dans divers autres polyacryliques qui ont de multiples usages. Agents de tannage Copolymères Cuir pleine fleur Cuirs et peaux de bovins Hydrolysat de collagène Post-tannage Tannage synthétique Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : In the upgrading of tannery solid wastes, the commercial application of the by-products obtained is the key to attractive technological alternatives. In the particular case of chrome shavings hydrolysed by an alkaline-enzyme process, the uses of collagen hydrolysate (CH) are the driving force for the start-up of a project when consideration is given to the amounts generated and to the diversity of applications, in addition to the fact that basic chrome salts -obtained from the dissolution of the chrome cake - may be used as trouble-free assistants to the fresh tanning agent. The present paper, which follows the Part I of this study ; "Collagen Hydrolysate : ‘soluble skin’ applied in post-tanning processes I. Characterisation” (JSLTC, 2000, 84,29) shows the experimental results obtained from the manufacture of various types of bovine leathers carried out at the CITEC pilot plant and in tanneries using CH in the post-tanning processes. In addition, the interactions of CH with acrylic retanning agents, studied at laboratory scale, are included. CH performs in a synergistic fashion with various retanning agents. In addition to its cosmetic-lubricating effect which enhances the leather grain properties and provides greater softness improving the resistance of the fibrous tissue, there is also a ‘restoring effect’ upon the grain surface of the semi-finished leather, masking preservation defects and damage marks on the skin. The interaction with dyes is evident from the intensified colours and improved homogeneity of the dyeing. CITEC has developed, besides CH, a copolymer CH-acrylic acid : "acrylic-protein" retanning agent MCH-106, that shows good properties in the development of full grain leather and splits. The application of the CH and the acrylic-protein MCH-106 in processing full-grain leather generates leathers of similar or higher quality to the standard one. The application of CH in leather manufacture is an attractive response to the question of how to use the by-products derived from the treatment of the chrome shavings. Note de contenu : - EXPERIMENTAL DEVELOPMENT : Experiments at CITEC - ANALYSIS OF THE RESULTS : CH application trials at the tannery - Table 1 : Reduction in formic acid consumption in the 'mixture solutions' With regard to the sum of the individual values (expressed in %) - Table 2 : Reduction in the salt KCr (SO4)2.12H2O consumption in the ‘mixture solutions’ with regard to the sum of the individual values (expressed in %) - Table 3 : Physical properties of the upper leather prepared with acrylic-protein retanning agent MCH106 and CH En ligne : https://drive.google.com/file/d/1ApP8ftPrxBi4iuQPgF3ZwC9qWN4r9ckE/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39859 [article]

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