Examination of haloversatile bacteria on salted goatskin and inactivation of haloversatile bacteria via direct electric current / S. Kose in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIX, N° 4 (04/2024)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIX, N° 4 (04/2024) . - p. 184-197 Titre : Examination of haloversatile bacteria on salted goatskin and inactivation of haloversatile bacteria via direct electric current Type de document : texte imprimé Auteurs : S. Kose, Auteur ; P. Yilmaz, Auteur ; Meral Birbir, Auteur ; Yasar Birbir, Auteur Année de publication : 2024 Article en page(s) : p. 184-197 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Bactéries -- Comptage Bactéries -- Identification Bactéries haloversatiles Caractérisation Courants continus Cuirs et peaux -- Analyse Cuirs et peaux -- Détérioration Cuirs et peaux de chèvres Enzymes microbiennes Peaux salées Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Haloversatile bacteria are among the commonly found microorganisms that have the potential to damage hides and skins in the leather industry. Therefore, the objective of this study was to investigate the presence of haloversatile bacteria on salted goatskins, to characterize these microorganisms through the use of molecular and conventional test methods, to detect their impact on the skins, and finally find an effective solution to inactivate these microorganisms. Haloversatile bacteria were common inhabitants at salted goatskin samples obtained from the Tuzla Organized Leather Industry Zone in Türkiye. Total numbers of haloversatile bacteria, proteolytic haloversatile bacteria, and lipolytic haloversatile bacteria on ten salted goatskin samples ranged from 7×104 to 2.7×105 CFU/g, 1×104 to 8×104 CFU/g, and 1×104 to 1.3×105 CFU/g, respectively. In the present study, 88% of the isolates were protease-positive, 69% were lipase-positive, 8% were xylanase-positive, 27% were caseinase-positive, 23% were amylase-positive, 8% were DNase-positive, 31% were cellulasepositive, 54% were urease-positive, 100% were catalase-positive, and 54% were oxidase-positive. The bacterial isolates showed positive reactions for the utilization of different amino acids such as glycine, L-cysteine, L-proline, and L-threonine, having the highest rates of 88%, 80%, 80%, and 80%, respectively. However, L-histidine had a lower positive reaction rate of 31%. The halophilic bacterial isolates exhibited positive reactions for the utilization and acid production from different types of sugar, with glucose having the highest positive reaction rate of 81%, followed by maltose at 73%, xylose at 58%, galactose at 46%, and lactose at 42%. Haloversatile enzymeproducing bacteria were identified using biochemical and molecular methods, resulting in the identification of 17 different species. Micrographs obtained from the scanning electron microscope revealed the damage inflicted on the fresh goatskin structure by haloversatile bacteria. A direct electric current of 2.2 A was applied to the mixed culture of haloversatile bacteria for 25 minutes to find an effective inactivation method. The total count of the mixed culture of haloversatile bacteria decreased from 7.3×106 CFU/mL to 4 CFU/mL within 16 minutes. All seventeen haloversatile bacteria in the mixed culture were killed within 19 minutes. Note de contenu : - Collection of salted goatskin samples from tanneries and measurement of pH values - Determination of the total numbers of haloversatile bacteria, proteolytic, and lipolytic haloversatile bacteria on the salted goatskin samples - Isolation of haloversatile bacteria - Haloversatile bacterial identification - Determination of optimal growth conditions for haloversatile bacteria - Investigation of enzymatic properties of haloversatile bacteria - Utilization of different amino acids and carbon sources by haloversatile bacteria - Examination of the damage caused by enzyme-producing haloversatile bacteria on the goatskin sample using scanning electron microscope - Destruction of haloversatile bacteria using electric current - Examination of haloversatile bacterial cells before and after treatment with direct electric current using scanning electron microscopy - Table 1 : The salted skin sample codes, ph of salted skin samples, total haloversatile, total proteolytic haloversatile, total lipolytic haloversatile bacterial counts on salted goatskin samples (CFU/g) - Table 2 : The isolate codes, phylogenetically similar species, length (bp), similarity (%), accession number of haloversatile isolates obtained from salted goatskin samples - Table 3 : The effects of pH, NaCl contents and temperature values on the growth of haloversatile bacterial isolates - Table 4 : Enzymatic characteristics of haloversatile isolates obtained from salted goatskin samples - Table 5 : Utilization of different sugars and amino acids by haloversatile isolates - Table 6 : The pH values, temperature, voltage and the total counts (CFU/mL) of enzyme producing haloversatile bacteria in the direct electric current treatment En ligne : https://drive.google.com/file/d/1WN-TWYW9l8-TRlCWsX0w8KSiISJyWWKx/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40826 [article]

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Identification of gram-positive haloversatile bacteria in soak liquor samples and observation of their damage to sheepskin by scanning electron microscopy / Ozlem Ozbay in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 106, N° 6 (11-12/2022)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 106, N° 6 (11-12/2022) . - p. 255-263 Titre : Identification of gram-positive haloversatile bacteria in soak liquor samples and observation of their damage to sheepskin by scanning electron microscopy Type de document : texte imprimé Auteurs : Ozlem Ozbay, Auteur ; Pinar Caglayan, Auteur Année de publication : 2022 Article en page(s) : p. 255-263 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Bactéries -- Identification Bactéries haloversatiles Bains de trempe -- Analyse Cuirs et peaux -- Détérioration Cuirs et peaux de moutons Enzymes Une 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. Liqueurs de tannage Microscopie électronique à balayage Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In the leather industry, the salting process is applied to raw hides in order to prevent microbial activity. Salted hides and skins are then soaked to re-absorb the water lost during salting and also to clean the salted hides and skins. Due to the organic load, salt and faeces present in the soak liquor, the soak liquor provides a suitable environment for the growth of bacteria. Bacteria that develop on the hide/skin may cause significant damage to these hides and skins. Therefore, the aims of the present study were to examine the pH values and salt saturation of the soak liquor samples, to detect the total counts of haloversatile bacteria, total counts of proteolytic haloversatile bacteria and total counts of lipolytic haloversatile bacteria in the soak liquor samples. Enzyme (amylase, caseinase, lipase, xylanase, cellulase, protease, DNase, pullulanase, urease, oxidase, or catalase) producing haloversatile bacteria were also isolated from these samples and they were identified with 16S rRNA gene sequence analysis. Their metabolic activities such as utilisation of different amino acid and carbon sources were tested. In addition, the damage caused to the skin structure by enzyme-producing haloversatile bacteria were examined using scanning electron microscope. The pH values and salt saturation of the samples were found as 8.80-9.30 and 3.5%- 5.5%, respectively. The total counts of haloversatile bacteria, proteolytic, and lipolytic haloversatile bacteria were respectively detected as 3.8 x 104-1.6 x 106CFU/mL, 1.2 x 104-5.8 x 105CFU/mL, and 6.3 x 104-4.6 x 105CFU/mL. Six haloversatile bacteria were isolated from the samples belonging to five different species such as Terribacillus halophilus, Brevibacterium luteolum, Bacillus australimaris, Bacillus siamensis, and Bacillus mojavensis. Various enzymes such as protease (83%), lipase (83%), caseinase (67%), amylase (50%), cellulase (17%) were produced by the isolates, on the other hand, none were xylanase, DNase, pullulanase and urease positive. Different sugar sources [lactose (100%), D-(+)-dextrose (100%), myo-inositol (100%), D-(+)- cellobiose (100%), adonitol (100%), D-(-)-salicin (100%), dulcitol (100%), D-mannose (100%), xylitol (83%), L-(+)-arabinose (83%), D-mannitol (67%), D-(-)-fructose (67%), D-(+)-trehalose (67%), D-(-)- ribose (50%), D-(+)-melezitose (33%) and sucrose (17%)] and different amino acid sources [L-serine (100%), L-glutamic acid (67%), DL-phenylalanine (67%), trans-4-hydroxy-L-proline (67%), L-proline (67%), glycine (50%), L-ornithine (50%), L-aspartic acid (33%), L- phenylalanine (33%), L-arginine (17%), L-histidine (17%), L-lysine (17%), L-threonine (17%)] were utilised by the isolates. D-sorbitol, D-(+)-galactose, maltose, D-(+)-xylose and D-(+)-melibiose, L-isoleucine, L-cystine, L-alanine, leucine, L-methionine, L-tyrosine and L-valine were not used. Note de contenu : - EXPERIMENTAL PROCEDURES : Soak liquor samples - Determination of temperature, pH and salinity values - Determination of total counts of haloversatile - DETERMINATION OF TOTAL COUNTS OF PROTEOLYTIC AND LIPOLYTIC HALOVERSATILE BACTERIA : Isolation of haloversatile bacteria - Determination of enzymatic activities of haloversatile bacteria - Utilisation of different amino acids and different sugars by haloversatile bacteria - 16S rRNA Sequences of DNA belonging to the haloversatile isolates - Nucleotide accession number - Examining the effects of pH, salt and temperature on haloversatile bacterial growth - Investigation of cell morphology an dpigmentation of haloversatile bacteria - Sheepskin curing process and storage - Preparation of sheepskin samples for examination under scanning electron microscope En ligne : https://drive.google.com/file/d/1pv1NXv_AA0sblUQelr9lGmsalSpOCx7c/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38518 [article]

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Negative effects of haloversatile bacteria in salt on skins and their control with direct electric current in the leather industry / Haider Sabah Abdulhusein in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 107, N° 6 (11-12/2023)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 107, N° 6 (11-12/2023) . - p. 207-214 Titre : Negative effects of haloversatile bacteria in salt on skins and their control with direct electric current in the leather industry Type de document : texte imprimé Auteurs : Haider Sabah Abdulhusein, Auteur ; Pinar Caglayan, Auteur ; Meral Birbir, Auteur ; Yasar Birbir, Auteur Année de publication : 2023 Article en page(s) : p. 207-214 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Bactéries haloversatiles Courants continus Cuirs et peaux -- Conservation Cuirs et peaux de chèvres Cuirs et peaux de moutons Microbiologie Sels de sodium Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The salt preservation method has been used for a long time in the leather industries with salt applied to raw skins and hides in order to control bacterial activity and to remove the moisture found in the skin structure. It is known that the salt used in curing process contains many halophilic bacterial species. During the salting process, skins and hides might be contaminated with these micro-organisms. The goal of this research was to determine factors including the pH of salt samples, total count of haloversatile bacteria, proteolytic haloversatile bacteria, and lipolytic haloversatile bacteria found in these samples and to isolate, and identify haloversatile bacteria from the salt samples, to test their ability to use various amino acid and sugar sources, to characterise their enzymatic properties, to investigate their adverse effects on sheepskinand goatskin samples using a scanning electron microscopy. In addition, 2.5A direct electric current was applied against mixed culture of enzyme-producing haloversatile bacteria in 15% NaCl solution to search for an alternative environmentally friendly preservation method for skin/hide curing. The pH values of salt samples were found to be between 7.60 and 8.04. The total counts of haloversatile bacteria, proteolytic haloversatile bacteria and lipolytic haloversatile bacteria were found to be 6 × 103CFU/g to 1.3 × 105CFU/g; 1×103-7×103CFU/g and 1.4 × 103-3.1 × 104CFU/g, respectively. 35 haloversatile bacteria belonging to ten different genera (Staphylococcus, Corynebacterium, Peribacillus, Lysinibacillus, Kocuria, Paenibacillus, Bhargavaea, Bacillus, Pseudomonas and Micrococcus) were isolated and identified from the salt samples. The ability of haloversatile bacteria to use sugars and amino acids varied from one genus to another genus. While catalase, esterase, urease, protease, caseinase, lipase, xylanase, cellulase, amylase, DNase and oxidase enzymes were produced among the isolates, pullulanase enzyme was not produced. The scanning electron microscope micrographs showed that enzyme-producing haloversatile bacteria had significant effects on goatskin and sheepskin. The total number of the mixed culture was reduced from 3.6 × 106CFU/mL to 4×101CFU/mL within 17 minutes, and all cells were completely killed within 21 minutes. The scanning electron micrographs showed that the structure and the organoleptic characterictics of bacteria treated sheepskin and goatskin samples were negatively changed at the end of 40-days storage. Note de contenu : - Salt sample collection and measuring pH value of salt samples - Determination of the total numbers of haloversatile bacteria in the salt samples - Determination of the total numbers of proteolytic and lipolytic haloversatile bacteria in salt samples - Isolation of haloversatile bacteria - Identification of haloversatile isolates according to 16S rRNA gene sequence analyses - Nucleotide accession number - Effects of different NaCl concentrations, pH values and temperature on haloversatile bacterial growth - Investigation of enzymatic properties of haloversatile bacteria - Utilisation of different amino acids and different carbon sources by haloversatile bacteria - Investigation the effects of the mixed culture of enzyme producing haloversatile isolates on sheepskin and goatskin - Extermination of haloversatile bacteria by direct electric current - Investigation of the bacterial cells before and after the treatment with direct electric current by scanning electron microscopy - Table 1 : The pH values, total counts of haloversatile bacteria, proteolytic haloversatile bacteria and lipolytic haloversatile bacteria in the salt samples - Table 2 : The effects of pH, NaCl contents and temperature values on bacterial growth - Table 3 : Enzymatic properties of haloversatile bacterial isolates - Table 4 : Utilization of different amino acids by haloversatile isolates - Table 5 : Utilisation of different sugars by haloversatile isolates - Table 6 : The pH values, temperature and the total counts (CFU/mL) of enzyme producing haloversatile bacteria in the direct electric current treatment En ligne : https://drive.google.com/file/d/1qRfWv_CwzI3WQkn8QhrK0n0Rq2zPAjwb/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40239 [article]

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