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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Fungal biotransformation of bovine hair. Part 2 : Biomass and proteases produced as a function of incubation time. Assessment of hair waste digestion / B. C. Galarza in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 90, N° 4 (07-08/2006)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 90, N° 4 (07-08/2006) . - p. 169-172 Titre : Fungal biotransformation of bovine hair. Part 2 : Biomass and proteases produced as a function of incubation time. Assessment of hair waste digestion Type de document : texte imprimé Auteurs : B. C. Galarza, Auteur ; L. M. Goya, Auteur ; M. L. Garro, Auteur ; J. Mercerat, Auteur ; R. A. Hours, Auteur ; Carlos S. Cantera, Auteur Année de publication : 2006 Article en page(s) : p. 169-172 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux Cystine La cystine est un acide aminé composé de deux unités cystéine liées par un pont disulfure. Déchets -- Valorisation Détérioration fongique Epilage Microscopie Peptidases Poils -- Biodégradation Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Unlike the conventional hair-saving unhairing processes, the modern processes considerably reduce the organic load from the beamhouse liquid effluent and yet a partially degraded 'hair waste' is generated, which has to be properly disposed of. It is estimated that a tannery processing 25 ton of salted cow hides will recover about 2.5 ton of wet hair per day. As was mentioned in the first part of the series 'Fungal biotransformation of bovine hair' the aim of our activities is to produce structural changes in the ‘hair waste’ using it as a solid substrate for the growth of the fungal species Trichophyton ajelloi and therefore weakening the keratinís resistance to hydrolysis processes. A strain of this microorganism, which was isolated from a Yak yard, has proved to be able to generate an enzymatic system capable of degrading hair keratin by means of specific proteases: the keratinases. Fungal activity also gave place to an enzymatic extract with activity upon the protein substrates of the epidermis and dermis of bovine hide. It should be noted that reports on fungal pathogenesis indicated that Trichophyton ajelloi presents no pathogenicity for men or animals. Upgrading the 'hair waste' by fungal biotransformation implies considering it as a raw material and not taking the current modality of 'throwing away proteins' to the soil (cost of transport and disposal of waste in landfills). Biodegradation offers on the one hand the attractive concept of 'feedback' since hair is the solid substrate upon which fungi act generating a degraded organic waste and a protein extract with proteolytic activity (keratinolytic among others) whose unhairing activity is evaluated. On the other hand an intermediate stage would be generated in the transformation of the ‘hair waste’ with potential uses in vermiculture and vermicompost. Note de contenu : - OBJECTIVES - MATERIALS AND METHODS : Culture conditions of the microorganism - Analytical techniques - Assessment of the degree of digestion of the ‘hair waste’ - RESULTS AND DISCUSSION : Microscopy observations - Assessment of digestibility - Cystine assessment in the ultrafiltered crude extract - Final remarks - Table 1 : Hair digestibility En ligne : https://drive.google.com/file/d/1fYmDuf6dOPGGOroT0Iv-Raf9r9NFKTRb/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39116 [article]

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