دورية أكاديمية
Identification, proteolytic activity quantification and biofilm-forming characterization of Gram-positive, proteolytic, psychrotrophic bacteria isolated from cold raw milk.
| العنوان: | Identification, proteolytic activity quantification and biofilm-forming characterization of Gram-positive, proteolytic, psychrotrophic bacteria isolated from cold raw milk. |
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| المؤلفون: | Mehdi Zarei, Sahar Elmi Anvari, Siavash Maktabi, Per Erik Joakim Saris, Amin Yousefvand |
| المصدر: | PLoS ONE, Vol 18, Iss 9, p e0290953 (2023) |
| بيانات النشر: | Public Library of Science (PLoS), 2023. |
| سنة النشر: | 2023 |
| المجموعة: | LCC:Medicine LCC:Science |
| مصطلحات موضوعية: | Medicine, Science |
| الوصف: | Psychrotrophic bacteria of raw milk face the dairy industry with significant spoilage and technological problems due to their ability to produce heat-resistant enzymes and biofilms. Despite extensive information about Gram-negative psychrotrophic bacteria in milk, little is known about Gram-positive psychrotrophic bacteria in milk, and their proteolytic activity and biofilm-forming characteristics. In the present study, Gram-positive, proteolytic, psychrotrophic bacteria of cold raw milk were identified, and their proteolytic activity and biofilm-forming capacity were quantified. In total, 12 genera and 22 species were represented among the bacterial isolates, however 50% belonged to three genera, namely Staphylococcus (19.4%), Bacillus (16.7%), and Enterococcus (13.9%). Different levels of proteolytic activity were detected in the identified isolates, even among the strains belonging to the same species. In addition, proteolytic activity was significantly higher at 25°C than at 7°C for all isolates. The crystal violet staining assay in polystyrene microtitre plates revealed a high level of variation in the biofilm-forming capacity at 7°C. After 72 hours of incubation, 11.1% of the strains did not produce a biofilm, while 27.8%, 52.8%, and 8.3% produced low, moderate, and high amounts of biofilm on polystyrene, respectively. The psychrotrophic bacteria were also able to produce biofilms on the surface of stainless steel coupons in ultra-high temperature milk after 72 h of incubation at 7°C; the number of attached cells ranged from 1.34 to 5.11 log cfu/cm2. These results expand the knowledge related to the proteolytic activity and biofilm-forming capacity of Gram-positive psychrotrophic milk bacteria. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 1932-6203 |
| العلاقة: | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0290953&type=printableTest; https://doaj.org/toc/1932-6203Test |
| DOI: | 10.1371/journal.pone.0290953&type=printable |
| DOI: | 10.1371/journal.pone.0290953 |
| الوصول الحر: | https://doaj.org/article/d4ba16c35d054e7cace8ea92ba130f14Test |
| رقم الانضمام: | edsdoj.4ba16c35d054e7cace8ea92ba130f14 |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 19326203 |
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| DOI: | 10.1371/journal.pone.0290953&type=printable |