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Collagen recovered, purified and enzymatically hydrolysed from tannery waste / M. E. Errasti in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 108, N° 1 (01-02/2024)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 108, N° 1 (01-02/2024) . - p. 1-8 Titre : Collagen recovered, purified and enzymatically hydrolysed from tannery waste Type de document : texte imprimé Auteurs : M. E. Errasti, Auteur ; Laura M. I. Lopez, Auteur Année de publication : 2024 Article en page(s) : p. 1-8 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Collagène Cuirs et peaux -- Déchets -- Recyclage Déchets industriels -- Recyclage Enzymes végétales Hydrolysat de collagène Hydrolyse Peptidases Produits chimiques -- Purification Récupération (Déchets, etc.) Tannage -- Déchets Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : One of the main challenges of the tannery industry is the management of the waste generated during the leather manufacturing process. This study aimed to recover the collagen from tanning industry waste to acquire knowledge about its conversion into high value-added ingredients with bio-functional properties. To this end, collagen was purified from rawhide waste from the leather industry, characterised by electrophoresis and compared with commercial collagen. Subsequently, it was subjected to an enzymatic treatment using plant proteases from Bromelia hieronymi under mild reaction conditions to produce hydrolysates, since the production of bioactive peptides by enzymatic hydrolysis is a sustainable way of taking advantage of protein by-products. The hydrolysates were characterised by matrix-assisted laser desorption/ionisation time-of-flight (MALDI TOF) mass spectrometry, showing peptides with molecular weights ranging from 1,000 to 6,000 Da. Liquid chromatography-mass spectrometry (LC-MS/MS) analysis allowed identifying 31 peptides from the a, chain of type I collagen and another 13 from the a2 chain of type I collagen. The probability that the peptides identified were bioactive was predicted with the Peptide Ranker software ('in silico analysis'). This demonstrated that 70% of them had high bioactive potential. These results showed that the collagen recovered from the waste of the tannery industry and hydrolysed by proteases from Bromelia hieronymi becomes a suitable source to obtain a product with greater added value than the original material and with multiple potential industrial applications. Note de contenu : - Chemicals - Collagen recovery - Plant enzymatic preparation - Preparation of collagen hydrolysate - Collagen hydrolysate characterisation - Table 1 : Chemical characterisation of the spiits before and alter the preliminary processing. Values are expressed as meant SD - Table 2 : HC peptides identified by LC-MS/MS and the potential to be bioactive (a Score obtained with PeptideRanker) En ligne : https://drive.google.com/file/d/1Y7TX9F5xRUSAxM8b0VRzEpEI3v406L0t/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40927 [article]

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Identification of slightly halophilic bacteria from salted sheepskin samples and investigation of their biotechnological importance / Dilek Yalcin in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 108, N° 1 (01-02/2024)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 108, N° 1 (01-02/2024) . - p. 10-22 Titre : Identification of slightly halophilic bacteria from salted sheepskin samples and investigation of their biotechnological importance Type de document : texte imprimé Auteurs : Dilek Yalcin, Auteur ; Pinar Caglayan, Auteur ; Didem Berber, Auteur Année de publication : 2024 Article en page(s) : p. 10-22 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Antimicrobiens Bactéries -- Identification Bactéries halophiles Bactériocines Les bactériocines sont une famille de peptides ou protéines synthétisés naturellement par certaines bactéries. Une bactériocine consiste généralement en un composé protéique de 20 à 60 acides aminés. Les bactériocines ne sont pas des antibiotiques mais elles possèdent des propriétés antibiotiques : - Elles peuvent être bactériocides, c'est-à-dire éliminer certains micro-organismes. - Elles peuvent être bactériostatiques, c'est-à-dire inhiber la croissance de certains micro-organismes. Cuirs et peaux de moutons Diéthyldithiocarbamate de sodium Enzymes microbiennes Peaux salées Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In the leather industry, skins/hides are salted immediately after the animal is slaughtered to prevent the enzymatic activities of bacteria. Although the salt-curing method prevents the growth of mesophilic bacteria, halophilic bacteria can develop in skins/hides that are stored for a long time, causing a decrease in leather quality. In the literature, it has been stated that slightly halophilic bacteria are isolated from products with a certain concentration of salt content. Since there is no study on the presence of these bacteria in salted raw hides, slightly halophilic bacteria were isolated and molecularly identified from ten sheepskin samples which were stored at 20°C for 6 months in our study. Also their biotechnologically important enzymes were evaluated, their bacteriocin production capacity was determined and the antibacterial efficacy of a chemical (sodium dimethyldithiocarbamate) used in the leather industry at certain concentrations were tested against these isolates. The total number of slightly halophilic bacteria, the total number of proteolytic slightly halophilic bacteria and the total number of lipolytic slightly halophilic bacteria in skin samples were determined as 1 x 104 – 4 x 105CFU/g, 2 x 103 – 4 x 104CFU/g and 1 x 102 – 3 x 104CFU/g, respectively. A total of 20 slightly halophilic bacteria were isolated from skin samples. Gram-positive and rod-shaped isolates showed optimum growth at 3-5% salt, 37°C-45°C and pH7-8. Protease, lipase, DNase, pullulanase, xylanase and cellulase produced by 100%, 61%, 83%, 11%, 44%, 88% isolates, respectively. In addition, oxidase and catalase activities were detected in all isolates. It has been determined that the isolates were able to produce acids from different sugar sources (D-xylose, D-mannose, D-ribose, sucrose) and can use amino acids (L-cysteine, L-glycine, L-alanine, L-threonine) found in the skin’s structure. According to the 16S rRNA sequence analysis results, the isolates belonged to the Bacillus genus (B. rugosus, B. amyloliquefaciens, B. haynesii, B. aerius, B. safensis, B. pumilus, B. kochii, B. mojavensis and B. atrophaeus). Among all isolates producing bacteriocin, the bacteriocin produced by Bacillus aerius had a thermostable structure, did not lose its activity at high pH and salt values, completely inactivated its activity when treated with proteinase K enzyme, and had its antibacterial activity when treated with lipase enzyme. Therefore, considering that some species are resistant to antimicrobials, purified bacteriocins can be used as a preservative in the leather industry. The isolates were sensitive to tested chemical substance at a certain concentrations (4000, 2000, 1000, 500, 250, 125, 62.5, 31.2, 15.6, 7.8μg/mL) and minimum inhibitory concentration (MIC) were detected. The MIC values of the isolates were determined as as 62.5μg/mL (B. rugosus), 31.2μg/mL (B. haynesii, B. safensis, B. mojavensis) 15.6μg/mL (B. amyloliquefaciens, B. aerius, B. kochii) 7.8μg/mL (B. pumilus) and 3.9μg/mL (B. atrophaeus). In this way, unnecessary use of chemicals in the soaking process will be prevented. Note de contenu : - Collection of salted sheepskin samples - Total number of slightly halophilic bacteria and isolation process - Detection of total numbers of proteolytic and lipolytic slightly halophilic bacteria - Determination of salt concentrations, temperatures and pH values for each isolate - Enzymatic activity tests of isolates - Biochemical tests of isolates - Molecular identification - Investigation of bacteriocin production capabilities of slightly nalophilic bacteria - Effects of different environmental conditions on bacteriocin activity - Determination of susceptibility of isolated slightly halophilic bacteria to antimicrobial agent by disk diffusion method - Table 1 : The total number of slightly halophilic bacteria, proteolytic slightly halophilic bacteria and lipolytic slightly halophilic bacteria in sheepskin samples (CFU/g) - Table 2 : Salt concentration, pH and temperature range results in which slightly halophilic bacteria isolates can grow - Table 3 : Isolate codes, base length (bp), similarity rate (%), phylogenetically similar species and accession numbers of slightly halophilic bacteria isolates - Table 4 : Frequency of slightly halophilic bacteria isolates in salted sheepskins - Table 5 : Biochemical characteristics and enzymatic activity results of isolates - Table 6 : Bacteriocin production of slightly halophilic bacterial isolates against each other - Table 7 : Determining optimum environmental conditions for bacteriocin activity - Table 8 : Antimicrobial effect of tested antimicrobial agent against isolates of slightly halophilic bacteria B. haynesii B. rugosus B. safensis B. mojavensis B. atrophaeus B. amyloliquefaciens B. aerius En ligne : https://drive.google.com/file/d/1rqhgvBtB4BA4cbuNl03NaM2VE62-SqSR/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40928 [article]

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Optimisation of preparation process and regulation of properties for composite material made from pineapple leaf fibre-natural latex-regenerated leather (RL-NL-PLF) used as home decor / Fugin Zhou Pengli in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 108, N° 1 (01-02/2024)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 108, N° 1 (01-02/2024) . - p. 23-27 Titre : Optimisation of preparation process and regulation of properties for composite material made from pineapple leaf fibre-natural latex-regenerated leather (RL-NL-PLF) used as home decor Type de document : texte imprimé Auteurs : Fugin Zhou Pengli, Auteur ; Yinghua Ma, Auteur Année de publication : 2024 Article en page(s) : p. 23-27 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Ananas et constituants Composites à fibres végétales Cuir reconstitué Fibres végétales Fibres végétales -- Propriétés mécaniques Fibres végétales -- Propriétés physiques Humidité -- Absorption:Eau -- Absorption Latex Mouillabilité Perméabilité Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In this experiment, pineapple leaf fibre was added to the composite material made by combining natural latex/regenerated leather to create by hot pressing a home decoration composite material. It was found that the appearance and quality of the composite prepared by adding 15% pineapple leaf fibre gave the best results. Compared with the composite without the addition of pineapple leaf fibre, it was found that the tensile strength, elongation at break, breaking strength, air permeability, water permeability, water absorption and surface wettability were greatly improved, which made it more suitable for making home decoration products. Note de contenu : - Analysis of the appearance RL/NL/PLF in different formulations - Analysis of the mechanical effect of pineapple leaf fibre supplemental level on RL/NL/PLF performance - Comparative analysis of physical properties of RL/NL/PLF and RL/NL En ligne : https://drive.google.com/file/d/1j7b8KG5h9A8uf44ow_0iyb3uyy03fYKN/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40929 [article]

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Properties of epoxy modified starch tanning agent combined with aluminum salt / Hao Dongyan in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 108, N° 1 (01-02/2024)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 108, N° 1 (01-02/2024) . - p. 28-35 Titre : Properties of epoxy modified starch tanning agent combined with aluminum salt Type de document : texte imprimé Auteurs : Hao Dongyan, Auteur ; Su Rongrong, Auteur ; Wei Chao, Auteur ; Xu Liqiang, Auteur ; Wang Xuechuan, Auteur Année de publication : 2024 Article en page(s) : p. 28-35 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Agents de tannage Amidon modifié Analyse sensorielle Croûte (cuir) On entend par "cuir en croûte" des cuirs ayant subi les opérations jusqu'au tannage, à l'exclusion de toute opération de corroyage ou de finissage, mais qui, par opposition aux wet-blue ont été séchés. Cuir -- Propriétés tinctoriales Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux -- Propriétés physiques Cuirs et peaux de moutons Epoxydes Résistance à la déchirure Résistance à la traction Résistance au jaunissement Sels d'aluminium Stabilité chimique Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : In order to investigate a new clean and chromium-free tanning method, an epoxy-modified starch (SCT) tanning agent was prepared from natural corn starch degradation products and we have examined its combined tanning effect with aluminum salts. The results showed that when the offer of SCT tanning agent was 8% of the mass of pickled sheep, and the offer of aluminum salt was 6%, at a tanning pH of 4.0, the shrinkage temperature (Ts) of crust leather could reach 79.8°C. In this situation, the SCT tanning agent and aluminum salt tanning agent cross-linked with the collagen. After the combination of SCT tanning agent and aluminum salt, the tensile strength of the leather reached 26.27MPa, the tear strength was 37.52N/mm, and the elongation at break was 70.07%, which was obviously better than that of the leather tanned with SCT alone. Moreover, the leathers tanned with SCT and aluminum salts showed good elution resistance to different chemical media, avoiding the fading defects caused when using aluminum tanning alone. Note de contenu : - EXPERIMENTAL SECTION : Materials - Methods - Characterisation and property testing - RESULTS AND DISCUSSION : Optimisation of the amount of SCT tanning agent - - Optimisation of the amount of aluminum sulfate - Chemical stability of crust leather - Physical and sensory properties of crust leather - Whiteness and yellowing resistance of crust leather - Analysis of dyeing properties of leather - Dispersion of collagen fibres in the cross section of crust leather - Table 1 : Application of SCT as pre-tanning agent - Table 2 : Tanning process of aluminum sulfate based on SCT pre-tanning En ligne : https://drive.google.com/file/d/127aVeLXRvrnkb5Wkoe8H68dwfNwdUfy4/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40930 [article]

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