Technologically important properties of lactic acid bacteria isolated from raw milk of three breeds of Algerian dromedary (Camelus dromedarius)

A total of 9 samples of individual dromedary raw milks from N’ajjer (3), Targui (3) and Reguibi (3) breeds were collected from 3 camels nomad herd in south Algeria and were analysed for bacterial load. A totalof 23 strains of lactic acid bacteria were isolated, out of which 12 strains were cocci and 11 strains were facultatively heterofermentative lactobacilli. Lactic acid bacteria were identified on the basis ofphenotypic characters as Lactococcus lactis subsp. lactis, Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, Lactobacillus paracasei subsp. paracasei, Lactobacillus plantarum andLactobacillus rhamnosus. Whole cells of lactococci, enterococci and lactobacilli showed proteolytic activity and were found to differed in terms of their acidifying activities. Proteolytic and autolyticactivity were generally higher for most lactobacilli compared to other isolates and none of the strains produced biogenic amines in the method applied. A wide variety of this 23 lactic acid bacteria strainsisolated from Algerian dromedary milks that showed potentially important properties suggest that they are good candidate for camels milk processing or other dairy fermentation process

Dinâmica de populações de plantas daninhas na cultura da soja.

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Strongly Coupled Electron–Phonon Dynamics in Few-Layer TiSe_2 Exfoliates

Ultrafast electron diffraction is used to probe the time-resolved dynamics in a few-layer TiSe_2 sample. At normal incidence, the suppression of the Bragg diffraction peak intensities following photoexcitation displays strongly biexponential behavior. For tilted samples, changes in the diffraction peak positions reveal coherent acoustic vibrations that are dependent on the sample thickness and that further permit a calculation of the Young’s modulus. The complex room temperature lattice dynamics observed are attributed to strong electron–phonon coupling and electron–lattice equilibration processes, which support a Jahn–Teller origin of the charge density wave behavior in TiSe_2. Additionally, the significant role that the related Kohn anomalies may play in the electron transport dynamics and transition mechanism of this material is emphasized. These results demonstrate the importance of strongly coupled electron–phonon dynamics in the relaxation of electronically excited room temperature TiSe2, which is expected to impact its applicability in optoelectronics