Fungal biotransformation of bovine hair : Assessment of structural changes / B. C. Galarza in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 91, N° 6 (11-12/2007)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 91, N° 6 (11-12/2007) . - p. 229-232 Titre : Fungal biotransformation of bovine hair : Assessment of structural changes Type de document : texte imprimé Auteurs : B. C. Galarza, Auteur ; Maria Laura Garro, Auteur ; Ivana Alejandra Cavello, Auteur ; M. C. Cazau, Auteur ; R. A. Hours, Auteur ; Carlos S. Cantera, Auteur Année de publication : 2007 Article en page(s) : p. 229-232 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Champignons microscopiques Déchets industriels -- Recyclage Déchets organiques -- Recyclage 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. Poils -- Biodégradation Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The hair-saving unhairing process generates another solid waste in the beamhouse area, regardless of the process used. Changes in unhairing technology have altered the problem of the high organic load and suspended solids of the beamhouse liquid effluent into a new problem : the disposal of the concentrated hair waste. Given that daily generation of ‘hair waste’ is considerable (approx. 2.5 tons per 1000 salted bovine hides processed) and that this waste can be considered as a raw material due to its physical and chemical properties, it is interesting to orientate our activities towards the investigation and development of technological alternatives to facilitate adding value. A typical analysis of the ‘hair waste’ after a hair saving unhairing process is within the following ranges. Total solids: 25-30%, total nitrogen: 11-15%, Ca++: 2-3%, Na+: 1-2%, S: 3-5%, (% moisture-free basis), sulphides : 80-100mgH2S/kg of recovered wet hair (filtered and drained, moisture 75%). The relevant organic component of the hair is the fibrous keratin protein which is very resistant to hydrolysis by chemical-physical and biological methods. Keratin has high stability as a consequence of the disulphide bridges of cysteine amino acid between adjacent protein chains. Biodegradation of hair by fungi is among the relevant alternatives to add value to ‘hair waste’. Using the waste as a solid substrate for fungal growth, a higher bioavailability is achieved for further use in agricultural technology for example. Moreover, this process offers the attractive concept of ‘feedback’, because biodegradation generates an enzymatic extract with potential applications in leather technology. Note de contenu : - OBJECTIVES - MATERIALS AND METHODS : Isolation of fungus with keratinolytic activity - RESULTS : Sample observation by Scanning Electron Microscopy - Table 1 : Specific enzymatic activity of the extract on different substrates, protein concentration and the final content of biomass of the culture - Table 2 : Comparison of the proteolytic activity of the fungal extract and commercial preparations En ligne : https://drive.google.com/file/d/1kLrOXHodiSIj0FUc8-yaNSHmcO5haDJu/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39003 [article]

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Optimization of keratinolytic protease production by purpureocillium lilacinum LPS # 876 as a sustainable management of tannery hair waste / Ivana Alejandra Cavello in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVIII, N° 8 (08/2013)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVIII, N° 8 (08/2013) . - p. 300-310 Titre : Optimization of keratinolytic protease production by purpureocillium lilacinum LPS # 876 as a sustainable management of tannery hair waste Type de document : texte imprimé Auteurs : Ivana Alejandra Cavello, Auteur ; Sebastiàn Fernando Cavalitto, Auteur Année de publication : 2013 Article en page(s) : p. 300-310 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Biodégradation Cuirs et peaux -- Déchets -- Recyclage Déchets organiques -- Recyclage Kératinases Poils -- Recyclage Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Hair waste is recognized as a solid waste generated after a hair-saving unhairing process in leather technology, and it is produced in large amounts in Buenos Aires province, Argentine. The present method for this solid waste is disposal, which is environmentally troublesome and costly for the tanneries. Biodegradation of hair waste by keratinolytic microorganisms represents an alternative for bioconversion of keratin waste. This paper reports the optimization of keratinases production by Purpureocillium lilacinum LPS # 876. Firstly, one factor-at-a-time method was used to investigate the effect of nitrogen-sources, metal ions concentration in the basal mineral medium, as well as, initial pH and temperature on enzyme production. Medium composition for the keratinases production by P. lilacinum was optimized using two statistical methods: Plackett-Burman design and central composite design -combined with response surface methodology- used to optimize three significant variables: initial pH, glucose and CaCl2. The optimal conditions were determined as 7.10 g l-1 of glucose; 0.0065 mg l-1 of CaCl2 and initial pH of 5.60; at this condition the maximum keratinase yield predicted was 26.7 U ml-1. The model validation showed that it described adequately the influence of glucose and calcium concentration and initial pH on enzyme production. Production of keratinases by P. lilacinum is a less-exploited field that might represent a novel and promising biotechnological application for this microorganism. Note de contenu : - MATERIALS AND METHODS : Reagents - Microorganism and culture conditions - Determination of proteolytic activity - OPTIMIZATION OF FERMENTATION MEDIUM USING ONE-VARIABLE-AT-A-TIME METHOD : Effect of environmental conditions on production keratinases - Effect of the concentration of the metal ions present in the basal mineral medium - Effect of the addition of some salts on keratinolytic enzymes production - Effect of nitrogen sources - Identification of the significant factors by Plackett-Burman (PB) design - Central Composite Design and Response Surface Methodology - BIOCHEMICAL PROPERTIES OF CRUD ENZYME : Detection of keratinolytic activity on polyacrylamide gels (casein and keratin-zymograms) - Substrate specificity - RESULTS : Optimization using one-variable-at-a-time approach - Selection of significant variables by Plackett-Burman design - Optimization by response surface methodology (RSM) - Detection of keratinolytic activity on polyacrylamide gels (casein and keratin-zymograms) - Substrate specificity En ligne : https://drive.google.com/file/d/1UOY6o8dh6sX7U4bHC-G1WlIdxLmn3DgC/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=19179 [article]

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