RESUMO
Lactic acid bacteria (LAB) synthesize exopolysaccharides (EPS), which are structurally diverse biopolymers with a broad range of technological properties and bioactivities. There is scientific evidence that these polymers have health-promoting properties. Most commercialized probiotic microorganisms for consumption by humans and farmed animals are LAB and some of them are EPS-producers indicating that some of their beneficial properties could be due to these polymers. Probiotic LAB are currently used to improve human health and for the prevention and treatment of specific pathologic conditions. They are also used in food-producing animal husbandry, mainly due to their abilities to promote growth and inhibit pathogens via different mechanisms, among which the production of EPS could be involved. Thus, the aim of this review is to discuss the current knowledge of the characteristics, usage and biological role of EPS from LAB, as well as their postbiotic action in humans and animals, and to predict the future contribution that they could have on the diet of food animals to improve productivity, animal health status and impact on public health.
RESUMO
Numerous reports describe the antioxidant and antimicrobial activity of polyphenols-rich plant extracts. The aim of this study was to determine the total polyphenols content (TPC), and the in vitro (DPPH, FRAP and TEAC) antioxidant and antibacterial activity of leaves and wood of six native woody species (Aspidosperma quebracho-blanct, Sarcomphalus mistol, Geoffroea decorticans, Prosopis chilensis, Larrea divaricata and Larrea cuneifolia) from Catamarca. Also, the phenolic profile was determined in the species with higher activity. L. cuneifolia leaf extracts showed the highest antioxidant activity followed by L. divaricata and S. mistol, while S. mistol wood extracts showed the highest. Furthermore, Larrea species showed antibacterial activity against S. aureus and E. faecalis strains showing cidal effects mainly against S. aureus. Fifty-nine polyphenols were identified in leaves and wood of Larrea and S. mistol species, which are likely to be responsible for the different activities observed.