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Hair saving unhairing process - Part 4. Remarks on the evolution of the investigations on enzyme unhairing - JSLTC Vol. 85, N° 4 - 07-08 2001.pdf / Carlos S. Cantera in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 85, N° 4 (07-08/2001)
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Titre : Hair saving unhairing process - Part 4. Remarks on the evolution of the investigations on enzyme unhairing - JSLTC Vol. 85, N° 4 - 07-08 2001.pdf Type de document : texte imprimé Auteurs : Carlos S. Cantera, Auteur Année de publication : 2001 Article en page(s) : p. 125-132 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux
Epilage enzymatiqueIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : In this new article of the series "Hair saving unhairing process" the development of the theme of enzyme unhairing is initiated. It gathers three curious features : it has been extensively studied by many researchers in different countries during the last century, it is scarcely used in the industry and it still keeps the attraction, as a challenge, to keep on calling together the interest of research groups that find in this process the ideal unhairing process.
Enzymatic unhairing will be the ideal unhairing process when the enzyme specificity is guided specially towards the components of the epidermis system, its action on the structured proteins—especially the collagen—is minimized or avoided, and when leather is developed with desirable properties.
The aim of this first article on the enzyme unhairing is to show—with no intention of being exhaustive—the research evolution of those work groups that showed relevant activity, adding in each of the sections comments and complementary suggestions from other work. Experimental studies and theoretical speculation at the Leather Research and Development Centre (CITEC) on the hair—saving unhairing process, particularly enzyme unhairing, tries to contribute to better knowledge on mechanisms (diffusive and chemical) involved in the unhairing, with the purpose of proposing the design of enzyme preparations to bring us closer to ideal unhairing.
The introduction of the research evolution on the enzyme unhairing, the behaviour of enzyme preparations on different substrates, the mechanisms that can take place in the process and the desirable/undesirable properties of resultant leather come before the presentation of the experimental results that are being obtained at CITEC. Thus, we will show in a further article, the results of the characterisation of commercially available enzyme preparations through the evaluation of proteolytic activities against a representative substrate of animal hide components and the activation inhibition effects that an unhairing system has on enzymes.En ligne : https://drive.google.com/file/d/11NnYX35BV5FNy11vL-JXMSFnzprIfIiS/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40243
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 85, N° 4 (07-08/2001) . - p. 125-132[article]Hair saving unhairing process. Part 5 characterisation of enzymatic preparations applied in soaking and unhairing processes / Carlos S. Cantera in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 87, N° 2 (03-04/2003)
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Titre : Hair saving unhairing process. Part 5 characterisation of enzymatic preparations applied in soaking and unhairing processes Type de document : texte imprimé Auteurs : Carlos S. Cantera, Auteur ; L. Goya, Auteur ; Betina Galarza, Auteur ; Maria Laura Garro, Auteur ; Laura M. I. Lopez, Auteur Année de publication : 2003 Article en page(s) : p. 69-77 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Caractérisation
Epilage enzymatique
Peaux brutes -- TrempeIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Considering the importance that is attached to the characterisation of proteolytic enzymatic preparations employed in leather making, especially in the development of enzyme unhairing, our studies are aimed to develop a protocol of analysis that allows us to determine the behaviour of the enzymes on diverse protein skin substrates. In the protocol presented here it is important to highlight the incorporation of the so-called ‘epidermis substrate’, comprising the epidermis layer, hair and the root sheaths, as well as the procedure to assess enzymatic action on the proteoglycans.
On two of the substrates, “epidermis” and Hide Powder Azure, studies on activation/inhibition of the enzyme activity using components usually added in the soaking and unhairing processes was also carried out.
The protocol was applied to two commercial enzymatic preparations commonly used in leather processing, and to an extract of vegetable proteases that CITEC, jointly with LIPROVE, is applying in its investigation on enzyme unhairing.
The protocol developed is a useful tool to assist us in the design of ideal enzyme unhairing: that in which the enzymatic activity is orientated towards the components of the epidermis system, when their action on fibrous proteins – particularly collagen - is minimised or avoided and when the leathers developed have the desired properties.Note de contenu : - INTRODUCTION : Chromogenic substrates - The epidermis layer, hair and root sheaths : the ‘epidermis substrate’ - Activity on proteoglycans (PGs) and hide powder substrate
- OBJECTIVES
- MATERIALS AND METHODS : 1) Assessment of protein content - 2) Assessment of activities on different substrates : Non – keratin based substrates - Activity upon proteoglycans (PGs). Hide powder substrate - Keratin-based substrates - 3) Inhibition and activation tests - 4) Protein Profile. Electrophoresis in SDS/polyacrylamide gel (PAGE) - 5) Isoelectric Focusing (IEF) - Zymogram
- EXPERIMENTAL RESULTS
- PROTEOLYTIC ACTIVITY AGAINST DIFFERENT SUBSTRATES AND ACTIVATION AND INHIBITION ASSAYS
- ANALYSIS OF THE RESULTS : Activation and Inhibition Tests
- Table 1 : Proteolytic activity of the enzymatic preparations against different substrates
- Table 2 : Ranges of pH corresponding to 90% of the maximum activity for each one of the enzymatic preparations (maximum activity pH value is shown in brackets)
- Table 3 : Changes in the activity of Alcamax and Pellvit against the chromogenic substrates hide powder azure and ‘epidermis’ adding components used in soaking and unhairing processes (*)En ligne : https://drive.google.com/file/d/1lrLmDHNIHN7pji0LbISFfwO_LGJtTNU1/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39802
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 87, N° 2 (03-04/2003) . - p. 69-77[article]Heterologous expression of alkaline metalloproteinases in bacillus subtilis sck6 for eco-friendly enzymatic unhairing of goatskins / Shihao Zhang in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 3 (03/2022)
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Titre : Heterologous expression of alkaline metalloproteinases in bacillus subtilis sck6 for eco-friendly enzymatic unhairing of goatskins Type de document : texte imprimé Auteurs : Shihao Zhang, Auteur ; Ruoshi Zhang, Auteur ; Xiaoguang Li, Auteur ; Zhe Xu, Auteur ; Yongqiang Tian, Auteur Année de publication : 2022 Article en page(s) : p. 113-123 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Caractérisation
Cuirs et peaux -- Propriétés mécaniques
Cuirs et peaux de chèvres
Epilage enzymatique
Matériaux -- Coloration
Métalloprotéinases
Wet-blue (tannage)Peau tannée au chrome (le chrome donne une couleur bleue)Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In this study, alkaline metalloprotease gene 1067 was cloned from Planococcus halotolerans SCU63T and heterologously expressed in Bacillus subtilis SCK6. Using Luria Bertani (LB) broth medium as the initial medium, the optimal medium was obtained through a series of fermentation and culture optimization (g/L): yeast extract (10), soybean powder (15), urea (20), potassium chloride (6.7), calcium chloride (13.3), NaCl (10). On the basis of the optimal medium, the highest enzymatic activity of 1259.21 U/mL could be obtained by culturing at 30°C for 40 h. with pH 8, inoculation amount of 4% and filling amount of 50 mL. EDTA inhibits protease activity and PMSF promotes it, indicating that it was a metalloprotease rather than a serine protease. The optimum reaction temperature of the protease is 70°C, and the optimum pH is 9. The metal ions Zn 2+, Co2+ and surfactant β-ME, Tween 80 can improve the activity of the protease. The results of unhairing, SEM and staining show that this metalloprotease can completely dehair goatskin. Compared with the conventional chemical method, the goatskin after enzymatic unhairing has softer texture and smoother surface, and there is no obvious damage to the goatskin. Note de contenu : - MATERIALS AND METHODS : Materials - Construction of recombinant plasmid and expression of 1067 in B. subtilis SCK6 - Optimization of fermentations conditions - Purification of protease 1067 - Enzyme assay - Analysis of enzymatic properties - Unhairing function of protease 1067 - Characterization of protease 1067 unhairing
- RESULTS AND DISCUSSION : Construction of recombinant strain and identification of protease activity - Fermentation optimization - Purification and identification of protease 1067 - Effect of temperature on enzyme activity and stability - Effect of pH on enzyme activity and stability - Effect of metal ions on enzyme activity - Effects of chemicals on enzyme activity - Effect of organic solvents on enzyme activity - Analysis of unhairing - SEM and analysis of tissue staining
- Table 1 : Factors and levels for RSM
- Table 2 : ANOVA for quadratic model
- Table 3 : Effect of metal ions on enzyme activity
- Table 4 : Effect of chemicals on enzyme activity
- Table 5 : Effect of solvents on enzyme activity
- table 6 : Characterization of mechanical properties of wet blue skinDOI : https://doi.org/10.34314/jalca.v117i3.4892 En ligne : https://drive.google.com/file/d/1z4VjDZxnKDTJf0c5BtRxJKAwUieQ2jK9/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37602
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVII, N° 3 (03/2022) . - p. 113-123[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 23402 - Périodique Bibliothèque principale Documentaires Disponible Heterologous expression of metalloproteinases from planococcus halotolerans SCU63T and eco-friendly enzymatic dehairing of goatskin / Zhang Shihao in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 105, N° 3 (05-06/2021)
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Titre : Heterologous expression of metalloproteinases from planococcus halotolerans SCU63T and eco-friendly enzymatic dehairing of goatskin Type de document : texte imprimé Auteurs : Zhang Shihao, Auteur ; Ruoshi Zhang, Auteur ; Xiaoguang Li, Auteur ; Zhe Xu, Auteur ; Yongqiang Tian, Auteur Année de publication : 2021 Article en page(s) : p. 132-139 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Caractérisation
Cuirs et peaux de chèvres
Enzymes microbiennes
Epilage enzymatique
Métalloprotéinases
Microscopie électronique à balayage
Peptidases
pH
Produits chimiques -- Purification
Travail de rivière (cuir)Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In this study, a metalloproteinase gene from Planococcus halotolerans SCU63 was cloned and expressed in Bacillus sp. SCK6. LB broth medium was used as the initial medium and for a series of fermentation optimisations. The most suitable medium components were as follows (g/l) : yeast extract powder (20), casein (13), tryptone (7), NaCl (10), urea (8). When the inoculation amount was 2%, the filling amount was 100mL, the culture time was 370C, and the pH was 7.0 for 40 hours the protease production reached the highest. The enzyme activity was completely inhibited by EDTA. Surfactants, such as Tween 20, Tween 80, and TritonX-100, could improve the enzyme activity, while SDS could inhibit the enzyme activity. Under protease action, goatskin can be completely depilated at 37oc and 28 hours. Compared with the conventional chemical dehairing, the enzymatic dehairing opened up the goatskin elastic fibre without any hair root in the hair follicle, and the skin was of high quality. Note de contenu : - MATERIALS AND METHODS : Materials - Construction of recombinant plasmid and expression of 1030 in B. subtilis SCK6 - Optimisation of fermentation conditions - Purification of proteases - Determination of enzyme activity - Characterisation of enzymatic properties - Dehairing function of protease 1030 - Analysis of dehairing
- RESULTS : Construction of recombinant plasmid and its expression in SCK6 - Optimisation of fermentation conditions and RSM - Purification and identification of proteases 1030 - Effect of temperature on enzyme activity and stability - Effect of pH on enzyme activity and stability - Effect of NaCl concentration on enzyme activity - Effect of metal ions on enzyme activity - Effect of chemicals on enzyme activity - Effect of organic solvents on enzyme activity - Analysis of enzymatic dehairing - Analysis of SEM and staining
- Table 1 : Factors and levels for RSM
- Table 2 : ANOVA for quadratic model
- Table 3 : Effect of metal ions on enzyme activity
- Table 4 : Effect of chemicals on enzyme activity
- Table 5 : Effect of solvents on enzyme activityEn ligne : https://drive.google.com/file/d/15BWASUeWYefKBb5gBjgfaEyNcAG7bjbz/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35833
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 105, N° 3 (05-06/2021) . - p. 132-139[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 22745 - Périodique Bibliothèque principale Documentaires Disponible Interaction of enzymes and hide/leather based on microwave use / Jiacheng Wu in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 102, N° 4 (07-08/2018)
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Titre : Interaction of enzymes and hide/leather based on microwave use Type de document : texte imprimé Auteurs : Jiacheng Wu, Auteur ; Ting Sun, Auteur ; Jinwei Zhang, Auteur ; Wuyong Chen, Auteur Année de publication : 2018 Article en page(s) : p. 204-209 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Confitage Le confitage est une action biochimique effectuée au moyen de produits enzymatiques, qui a pour but de dégrader les fibres élastiques, contribuant ainsi à augmenter la souplesse du cuir. En outre, les enzymes complètent la dégradation des résidus épidermiques, donnant ainsi une fleur plus propre et plus lisse.
Cuirs et peaux de chèvres
EnzymesUne enzyme est une protéine dotée de propriétés catalytiques. Pratiquement toutes les biomolécules capables de catalyser des réactions chimiques dans les cellules sont des enzymes ; certaines biomolécules catalytiques sont cependant constituées d'ARN et sont donc distinctes des enzymes : ce sont les ribozymes.
Une enzyme agit en abaissant l'énergie d'activation d'une réaction chimique, ce qui accroît la vitesse de réaction. L'enzyme n'est pas modifiée au cours de la réaction. Les molécules initiales sont les substrats de l'enzyme, et les molécules formées à partir de ces substrats sont les produits de la réaction. Presque tous les processus métaboliques de la cellule ont besoin d'enzymes pour se dérouler à une vitesse suffisante pour maintenir la vie. Les enzymes catalysent plus de 5 000 réactions chimiques différentes2. L'ensemble des enzymes d'une cellule détermine les voies métaboliques qui peuvent avoir lieu dans cette cellule. L'étude des enzymes est appelée enzymologie.
Les enzymes permettent à des réactions de se produire des millions de fois plus vite qu'en leur absence. Un exemple extrême est l'orotidine-5'-phosphate décarboxylase, qui catalyse en quelques millisecondes une réaction qui prendrait, en son absence, plusieurs millions d'années3,4. Comme tous les catalyseurs, les enzymes ne sont pas modifiées au cours des réactions qu'elles catalysent, et ne modifient pas l'équilibre chimique entre substrats et produits. Les enzymes diffèrent en revanche de la plupart des autres types de catalyseurs par leur très grande spécificité. Cette spécificité découle de leur structure tridimensionnelle. De plus, l'activité d'une enzyme est modulée par diverses autres molécules : un inhibiteur enzymatique est une molécule qui ralentit l'activité d'une enzyme, tandis qu'un activateur de cette enzyme l'accélère ; de nombreux médicaments et poisons sont des inhibiteurs enzymatiques. Par ailleurs, l'activité d'une enzyme décroît rapidement en dehors de sa température et de son pH optimums.
Epilage enzymatique
Micro-ondes
Wet-blue (tannage)Peau tannée au chrome (le chrome donne une couleur bleue)Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : With the characteristics of high efficiency, specificity and mild reaction conditions, enzymes are able to catalyse many biochemical reactions. Hence, they are widely used in the soaking, unhairing, degreasing and bating processes in the leather industry. At present, there are a lot of studies on the interaction laws between protease and collagen under conventional water bath heating ; however, under microwave irradiation with both thermal and non-thermal effects, corresponding research has not yet been reported. In this work, enzymatic unhairing (EU), bating (EB) and wet-blue leather treating (ET) processes were investigated under microwave irradiation heating compared with water bath heating. Hydroxyproline concentration and chrome content were analysed by ultraviolet-visible absorption spectroscopy. The grain of the sample was observed with a microscope. Thermal performance and physical and mechanical properties of the collagen composites was characterised by the shrinkage temperature, softness, tensile and tear strength, respectively. The results showed thât microwave could increase EU and EB rates, EU was completed 2 hours earlier and the end of EB was 1 hour in advance. After microwave irradiation, the grain of the skin or leather had better flatness and softness. It also promoted enzymatic proteolysis, in which the hydroxyproline concentration in EB and ET was decreased by 0.26 mg/L and 0.12mg/L, respectively. In addition, microwave use lowered the removal of chromium in ET, and the chrome content was reduced by 11.96mg/L. Quite a long exposure to microwave irradiation would inactivate enzymes, slightly weakening the tensile and tear strength of the leather. The results indicated that microwave treatment could promote the leather manufacturing process and improve the performance of collagen composites, which may lay a foundation for the application of microwaves in the leather industry. Note de contenu : - EXPERIMENTAL PROCEDURES : materials - Enzymatic unhairing (EU) process - Enzymatic bating (EB) process - Enzymatic treatment (ET) of wet-blue goat leather
- RESULTS AND DISCUSSION : Microwave effect on EU - Microwave effect on EB - Microwave effect on ETEn ligne : https://drive.google.com/file/d/1Ld036J4ZIDxZ8VmpT4JEGTHhGEhKSqAP/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30904
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 102, N° 4 (07-08/2018) . - p. 204-209[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 20126 - Périodique Bibliothèque principale Documentaires Disponible KCl-assisted enzyme in unhairing and collagen fibre bundle opening for cleaner leather making / Yafei Zhang in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 104, N° 5 (09-10/2020)
PermalinkKey mechanism of enzymatic dehairing technology for leather-making : permeation behaviors of protease into animal hide and the mechanism of charge regulation / Mengchu Gao in COLLAGEN AND LEATHER, Vol. 5 (2023)
PermalinkMathematical analysis of depilation using combinations of amylase and protease / Jian Song in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 91, N° 5 (09-10/2007)
PermalinkNeutral protease assisted low-sulfide hair-save unhairing based on pH-sensitivity of enzyme / Yunhang Zeng in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXI, N° 9 (09/2016)
PermalinkPermalinkA novel approach for quantitative characterization of hydrolytic action of glycosidases to glycoconjugates in leather manufacturing / Fengxiang Luo in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXV, N° 7 (07/2020)
PermalinkOptimization of dehairing/fiber opening using ammonium chloride/dispase by response surface methodology / Tang Chao in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 7 (07/2022)
PermalinkOxidative unhairing versus sulphide use - A critical comparison / Reno Spinosi in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 102, N° 1 (01-02/2018)
PermalinkPermalinkQuantitative determination of enzymatic and chemical dehairing of skins by an electronic force sensor / Arife Candas Adigüzel Zengin in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVI, N° 12 (12/2011)
PermalinkRapid fiber opening process for skins : an approach for fail-safe chemical-free process / Jayanthi Durga in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 1 (01/2015)
PermalinkRecovery of industrially useful hair and fat from enzymatic unhairing of goatskins during leather processing / Joseph Ondari Nyakundi in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 6 (06/2022)
PermalinkResource utilization of bovine hair recycling from enzymatic unhairing during leather manufacturing : Alkali-protease synergistic preparation of keratin and its in vitro antioxidant activity / Ting Liu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVIII, N° 9 (09/2023)
PermalinkScreening of additives to reduce grain damage risk on unhairing by proteinase K / Mei Chen in JOURNAL OF LEATHER SCIENCE AND ENGINEERING, Vol. 2 (Année 2020)
PermalinkStudies on the use of bi-functional enzyme for leather making / Gladstone Christopher Jayakumar in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXI, N° 12 (12/2016)
PermalinkPermalinkThe changes in fibre structure of ox hide on enzyme unhairing and tanning as sole leather / R. S. Andrews in JOURNAL OF THE SOCIETY OF LEATHER TRADES' CHEMISTS, Vol. 50, N° 6 (06/1966)
PermalinkThe characterisation and depilation effect of extracellular proteases of streptomyces sp. TYQ1024 / Chufan Cai in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 106, N° 3 (05-06/2022)
PermalinkUnhairing of bovine skin with fungal enzymes by immersion and spread throughout the epidermis / Maria Laura Garro in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 103, N° 1 (01-02/2019)
PermalinkUnhairing with enzymes / A. Crispim in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 87, N° 5 (09-10/2003)
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