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Diffusion and reaction behavior of proteases in cattle hide matrix via FITC labeled proteases / Jianzhong Ma in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 5 (05/2014)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CIX, N° 5 (05/2014) . - p. 138-145 Titre : Diffusion and reaction behavior of proteases in cattle hide matrix via FITC labeled proteases Type de document : texte imprimé Auteurs : Jianzhong Ma, Auteur ; Xueyan Hou, Auteur ; Dangge Gao, Auteur ; Jing Zhang, Auteur Année de publication : 2014 Article en page(s) : p. 138-145 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Collagène -- Détérioration Cuirs et peaux de bovins Diffusion (physique) Hydrolyse enzymatique Isothiocyanate de fluorescéine L'isothiocyanate de fluorescéine (FITC, fluorescein isothiocyanate en anglais) est un dérivé de la fluorescéine utilisée dans un large spectre d'applications comme la cytométrie en flux. Le FITC est une molécule de fluorescéine fonctionnalisée avec un groupe réactif isothiocyanate (-N=C=S), remplaçant un atome d'hydrogène sur le cycle le plus bas de la structure. Ce dérivé réagit avec les nucléophiles comme les groupes amines et sulfhydryles des protéines. Un groupe fonctionnel succinimidyle-ester greffé au noyau fluorescéine, créant le NHS-fluorescéine, forme un autre dérivé commun réagissant avec les amines, possédant une plus grande spécificité envers les amines primaires en présence d'autres nucléophiles. Le FITC possède un pic d'excitation et d'émission à 495 nm et 521 nm respectivement. Comme la plupart des fluorochromes, il est sujet au photobleaching. Par conséquent, des dérivés de la fluorescéine tels que l'Alexa 488 et le DyLight 488 ont été optimisés pour des applications chimiques et biologiques nécessitant une plus grande photostabilité, une plus grande intensité de fluorescence ou l'ajout de groupements différents. Peptidases Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Enzymes play an important role in the biological treatment of animal skin collagen in the leather making process. In this work, three proteases (2709, LimeG and SoakL) with different molecular weight were used in the treatment of cattle hide. Protein and hydroxyproline absorbance was measured to evaluate the treatment effectively. Proteases labeled by Fluorescein Isothiocyanate (FITC) were used to treat the cattle hide to observe the diffusion and reaction behavior of proteases in cattle hide matrix. The results indicate that when the cattle hide was treated with smaller molecular weight protease, the degradation degree of the protein and collagen was more than that of the cattle hide treated with larger molecular weight protease. The fluorescence microscopy images demonstrate that during the early stages, proteases chiefly diffused into the cattle hide matrix through pores and hair follicles, and then diffused into the inner layer via hair follicles to hydrolyze inter-fibrillary proteins for opening up collagen fibers. In the present investigation, a visible assessment for the diffusion and reaction behavior of proteases in the enzymatic treatment of cattle hide matrix was reported. Note de contenu : - MATERIALS AND METHODS : Materials - Instrumentation - Determination of the protease activity - Enzymatic treatment of cattle hide matrix - FITC labeled protease - Analysis - RESULTS AND DISCUSSION : Enzymatic treatment of cattle hide matrix - The effect of FITC on the activity of FITC labeled protease - Effect of molecular weights of protease on the diffusion - Diffusion and reaction mechanism of proteases in cattle hide matrix En ligne : https://drive.google.com/file/d/1QDPKDq7Hvzq6ren7nS9eHkiT-NiXMA66/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21285 [article]

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Skin characteristics of Cervus Elaphus L. from Republic of Tuva in Russia / Urana Dandar in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 5 (05/2014)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CIX, N° 5 (05/2014) . - p. 146-153 Titre : Skin characteristics of Cervus Elaphus L. from Republic of Tuva in Russia Type de document : texte imprimé Auteurs : Urana Dandar, Auteur ; Selime MenteÅŸ Çolak, Auteur ; Remziye Deveci, Auteur ; Arife Candas Adigüzel Zengin, Auteur ; Gökhan Zengin, Auteur Année de publication : 2014 Article en page(s) : p. 146-153 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Caractérisation Chimie analytique Cuirs et peaux de cerfs Histochimie Morphologie (matériaux) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Characteristics of an animal raw skin are closely related to the physical properties of finished leather obtained from the skin. Although numerous studies have been performed on determination of physical properties of tanned deerskin, characteristics of raw deerskin have not yet been described in literature. In the present study, data on morphological, histochemical and chemical characteristics of wild red deer (Cervus elaphus L.) skins obtained from Republic of Tuva within the Russia Federation are presented and the relevant differences between skins of other animal species described. Table Top Scanning Electron Microscopy (TSEM) and Scanning Electron Microscopy (SEM) were used to determine the morphological characteristics of raw deerskins. For histochemical studies the cross section of skins were observed by Research Microscopy (RM). Hydroxyproline content, Total Kjeldahl Nitrogen (TKN), volatile matter, fat content, water-soluble-matter, sulphated total ash and fatty acid contents of raw deerskins were analyzed to further characterize the chemical composition of deerskin. Deerskin has comparatively higher TKN values, lower fat content with higher unsaturated fatty acid ratio, when compared to sheepskin. TSEM and SEM analysis showed that fur fibers and guard hairs of red deer skin were characterized by large cortex and medulla respectively that provides good isolation properties. In addition, high hydroxyproline content, low fat content, and tightly packed collagen fibers revealed by histochemical observations consolidates the long lasting property of deer skin. Assessment of skin characteristics enabled gathering data on physical and chemical properties of red deer skin, which is significant in choosing appropriate potential raw material that will produce the most suitable leather for a specific application. Note de contenu : - EXPERIMENTAL : Materials - Methods - Morphological and histochemical investigations of deer skins - Chemical characterization of deer skins - RESULTS AND DISCUSSION : Morphological and histochemical investigations of deer skins - Chemical analysis En ligne : https://drive.google.com/file/d/1HUExMNVJrr2S7qawXJdqI7dimEiEjIJC/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21286 [article]

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Nutrient balance in aerobic biological treatment of tannery wastewater / Jianfei Zhou in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 5 (05/2014)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CIX, N° 5 (05/2014) . - p. 154-160 Titre : Nutrient balance in aerobic biological treatment of tannery wastewater Type de document : texte imprimé Auteurs : Jianfei Zhou, Auteur ; Ya-Nan Wang, Auteur ; Wenhua Zhang, Auteur ; Bi Shi, Auteur Année de publication : 2014 Article en page(s) : p. 154-160 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Déchets -- Elimination Eau -- Epuration -- Traitement biologique Eaux usées -- Analyse Tannage -- Déchets Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The effect of nutrient composition of tannery wastewater on aerobic biological treatment, particularly on the removal of ammonia nitrogen (NH3-N) and total nitrogen (TN) was investigated based on the theory of nutrient balance. During the biological treatment of conventional tannery wastewater, total organic carbon (TOC) and total phosphorus (TP) were almost exhausted. However, the removal of TN was unsatisfactory, suggesting that tannery wastewater contains excessive N source and insufficient C and P sources. When extra C and P sources were added together into the wastewater, the removals of NH3-N and TN increased significantly. Under the optimal ratio of TOC:TN:TP (10:1:0.2), the removals of NH3-N and TN were 100% and 80%, respectively, and the added C and P sources were almost consumed by activated sludge. This means that a good nutrient balance was achieved in this condition. Accordingly, when ammonium salts are replaced by organic acids and phosphates in the deliming and bating processes, it is reasonable to assume that the change of wastewater composition would favor the aerobic biological treatment of wastewater. Note de contenu : - EXPERIMENTAL : Materials - Procedures for aerobic biological wastewater treatment - Analytical methods - Aerobic biological treatment with the addition of C and P sources - Aerobic biological treatment with different C/N ratios - Aerobic biological treatment with different N/P ratios - Aerobic biological treatment using different P sources - RESULTS AND DISCUSSION : Characteristics of raw tannery wastewater and activated sludge - Effect of addition of C and P sources on aerobic biological treatment - Effect of C/N ratio on aerobic biological treatment - Effect of N/P ratio on aerobic biological treatment - Effect of different P sources on aerobic biological treatment En ligne : https://drive.google.com/file/d/1ZGQp-M93qeO35hs-KcFxBdLjNH-sSJ-g/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21287 [article]

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Studies of ethiopian sheepskins as an opportunity for value addition, part II : optimization and characterization of wanke upper and garment leather / H. Mohammed in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 5 (05/2014)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CIX, N° 5 (05/2014) . - p. 161-169 Titre : Studies of ethiopian sheepskins as an opportunity for value addition, part II : optimization and characterization of wanke upper and garment leather Type de document : texte imprimé Auteurs : H. Mohammed, Auteur ; G. Aysanew, Auteur ; Rathinam Aravindhan, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Chandra Babu Narasimhan Kannan, Auteur Année de publication : 2014 Article en page(s) : p. 161-169 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Caractérisation Cuirs et peaux -- Propriétés organoleptiques Cuirs et peaux de moutons Vêtements en cuir Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Ethiopian tanners face a shortage of raw material input for the production of leather. The government strategically planned for importing raw skins from neighboring countries and also for effective utilization of available raw material resources in the country. The meat of Wanke sheep is in high demand in international markets, but the skin commands low price not only due to low availability but also less demand by tanners due to natural problems associated with the skin. Hence, tanners treat the skin as a reject. The problems of Wanke skin include high natural fat deposition, thin substance and low strength. Usually, leathers made out of Wanke skins have low selections compared to Ethiopian sheep skins and are mainly utilized for making lining leather. In this work, efforts have been made to develop a process technology for making high value leathers with improved properties from Wanke sheepskin. Note de contenu : - MATERIALS AND METHODS : Process design and standardization - Physical characterization of the skin - RESULT AND DISCUSSION : Processing strategy - Organoleptic properties - Pilot scale trials for making wanke garment and ladies upper leathers En ligne : https://drive.google.com/file/d/1sZ5yZi_0u5m7oFbmIpCIcjFLSWCtSUiT/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21288 [article]

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