Caracterización y potencial probiótico de bacterias lácticas aisladas de leche de oveja guirradissertation
Аннотация: Probiotics are live microorganisms that exert a beneficial effect on the host when administered in adequate amounts.According to the requirements of FAO, a probiotic isolate must be identified to genus, species and strain level and in vitro studies have to be carried out to analyze the antimicrobial activity against pathogens, resistance to gastrointestinal conditions and adherence to the mucosa intestinal epithelial cells.In addition, to ensure the safety, antibiotic resistance, epidemiological and metabolic activities tests are recommended.Within the beneficial effects on health, the nutritional contribution, attenuation of lactose intolerance, improved digestibility, positive effect on the immune system, maintenance of normal intestinal microbiota, prevention of cancer, reduction of respiratory infections, cholesterol attenuation, improving health and gastric adjuvant treatments with antibiotics have to be highlighted.Several investigations indicate that several species belonging to the lactic acid bacteria (LAB) have these properties and are commonly found in dairy products.Today in Valencia are sold fresh and ripened cheeses made from Guirra sheep milk.However, no studies have been conducted to determine the potential probiotic strains isolated from this milk to date In this thesis, we have isolated 131 LAB strains from Guirra sheep milk.Following the above criteria, these strains were initially identified by phenotypic methods to genus and species level.Subsequently, we evaluated in vitro, the antimicrobial activity of lactic acid strains against pathogens involved in human diseases such as H. pylori and Salmonella spp.In particular, we have studied the effect of substances produced by two strains BAL compared to the viability of H. pylori.LAB prominent strains in the antimicrobial activity have been identified and characterized using molecular techniques, antibiotic resistance profiles, the ability of adherence to pig mucin and finally evaluated their resistance to gastrointestinal conditions.The results show that probiotic properties can be attributed to a strain in particular and can not be generalized to a species or genus level.Some of the lactic strains from sheep and CECT are of special interest because they demonstrated in vitro probiotic characteristics which should be confirmed in further in vivo studies.It must be
Год издания: 2011
Авторы: CLAUDIA MILENA AMOROCHO CRUZ
Ключевые слова: Probiotics and Fermented Foods, Microbial Metabolites in Food Biotechnology, Food composition and properties
Открытый доступ: bronze