Efficacy of antimicrobial agent containing sodium dimethyldithiocarbamate against halobacterium salinarum, haloarcula salaria and haloarcula tradensis causing red heat on salted sheepskins / Pinar Caglayan in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 106, N° 4 (07-08/2022)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 106, N° 4 (07-08/2022) . - p. 165-170 Titre : Efficacy of antimicrobial agent containing sodium dimethyldithiocarbamate against halobacterium salinarum, haloarcula salaria and haloarcula tradensis causing red heat on salted sheepskins Type de document : texte imprimé Auteurs : Pinar Caglayan, Auteur ; Meral Birbir, Auteur Année de publication : 2022 Article en page(s) : p. 165-170 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Antimicrobiens Concentration minimale inhibitrice (antimicrobiens) En microbiologie, la concentration minimale inhibitrice (CMI) est la plus faible concentration d'un produit chimique, généralement un médicament, qui empêche la croissance visible d'une ou de plusieurs bactéries. La CMI dépend du micro-organisme considéré, de l'être humain affecté (in vivo uniquement) et de l'antibiotique lui-même. La CMI est déterminée en préparant des solutions du produit chimique in vitro à diverses concentrations croissantes, en incubant les solutions avec des groupes séparés de bactéries en culture et en mesurant les résultats en utilisant une méthode de dilution standardisée (agar ou microdilution). Les résultats se classent ensuite comme "sensible", "intermédiaire" ou "résistant" à un antimicrobien particulier en utilisant un point d'arrêt. Les points d'arrêt sont des valeurs convenues, publiées dans les directives d'un organisme de référence, comme le US Clinical and Laboratory Standards Institute (CLSI), la British Society for Antimicrobial Chemotherapy (BSAC) ou le Comité européen sur les tests de sensibilité aux antimicrobiens (EUCAST). On a pu constater des écarts importants au niveau des points d'arrêt de divers pays européens au fil des ans, et entre ceux de l'EUCAST et du CLSI. Alors que la CMI est la concentration la plus faible d'un agent antibactérien nécessaire pour inhiber la croissance visible, la concentration bactéricide minimale (CBM) est la concentration minimale d'un agent antibactérien qui entraîne la mort bactérienne. Plus la CMI est proche de la CBM, plus le composé est bactéricide. La première étape de la découverte d'un médicament est souvent le dépistage d'un médicament candidat de banque de données pour les CMI contre les bactéries d'intérêt. En tant que tels, les CMI sont généralement le point de départ pour de plus grandes évaluations précliniques de nouveaux agents antimicrobiens. Le but de la mesure de la concentration minimale inhibitrice est de s'assurer que les antibiotiques sont choisis efficacement pour augmenter le succès du traitement. (Wikipedia) Cuirs et peaux -- Conservation Cuirs et peaux de moutons Diéthyldithiocarbamate de sodium Peaux brutes -- Salage Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Extremely halophilic archaeal populations producing protease and lipase enzymes in preservation salts can contaminate hides and skins during the salt-pack curing or brine curing process. The enzymatic activities of these micro-organisms may cause loose grain, resulting in a significant reduction of leather's commercial value. Controlling the growth of these micro-organisms is essential for quality leather manufacture. Therefore, we carried out investigations to inhibit protease and lipase positive extremely halophilic archaeal strains using an antimicrobial agent containing sodium dimethyldithiocarbamate. In this study, the agar dilution method was used to detect the minimum inhibitory concentrations of the antimicrobial agent against proteolytic and lipolytic Halobacterium salinarum, Haloarcula salaria, and Haloarcula tradensis which were isolated from salted sheepskins with red heat. Eighteen concentrations of sodium dimethyldithiocarbamate ranging from 4000 pg/ml to 0.028 µg/ml were separately applied to the test isolates. The minimum inhibitory concentration of sodium dimethyldithiocarbamate against Halobacterium salinarum, Haloarcula salaria, and Haloarcula tradensis was 62.5µg/ml. In conclusion, the antimicrobial agent containing sodium dimethyldithiocarbamate was highly effective against proteolytic and lipolytic extremely halophilic archaea. Hence, we suggest using this antimicrobial agent in the brine curing of hides and skins to prevent deterioration and increase the commercial value of leather. Note de contenu : - Preparation of different concentratons of antimicrobial agent - Preparation of brown agar medium containing different concentrations of sodium dimethyldithiocarbamate - Preparation of the test isolates - Table 1 : Preparation of different concentrations of antimicrobial agent with sodium dimethyldithiocarbamate - Table 2 : The efficacy and minimum inhibitory concentrations of sodium dimethyldithiocarbamate against extremely halophilic archaeal strains En ligne : https://drive.google.com/file/d/1y1VyRIzg6ZvkIaEtzPlOqlAi2jChvqOL/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37881 [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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