RESUMENCaracterísticas probióticas de cepas de Lactobacillus plantarum de mantequilla tradicional de leche de camello de regiones áridas (Sáhara) de Argelia.Se evalúan algunas características probióticas de cepas de Lactobacillus plantarum aisladas de la mantequilla tradicional elaborada a partir de leche de camello (shmen). De 38 cepas investigadas para resistencia biliar, 14 fueron tolerantes a un 2% oxgall con porcentajes de supervivencia entre 69 y 75%. De éstas, sólo 4 cepas (L. plantarum SH5, SH12, SH24 and SH32) fueron suficientemente resistentes a pH 2 con periodos de incubación entre 2 y 6 h. Únicamente los extractos crudos de L. plantarum SH12 y L. plantarum SH24 fueron inhibitorios frente a Lactococcus lactis B8, la cepa utilizada como indicador. La actividad antibacteriana de los extractos crudos se perdió completamente después de tratamiento con α-quimotripsina y proteinasa K. Las cepas SH12 y SH24 fueron susceptibles a la penicilina G, oxacilina, vancomicina y clindamicina, pero resistentes a tetraciclina y kanamicina. Dichas cepas mostraron una rápida actividad acidificante (0,921 y 1,075 mmol/l de ácido láctico, respectivamente), una buena actividad proteolítica (5,45 y 3,49 mg/l de tirosina a las 72 h, respectivamente) y un alto porcentaje de supervivencia después de liofilización. Ninguna de las cepas produjo polisacáridos o hemolisina en sangre de oveja.PALABRAS CLAVE: Antibiótico -Bacterias acidolácti-cas -Bacteriocina -Lactobacillus plantarum -Mantequilla -Probiótico. SUMMARY Probiotic characteristics of Lactobacillus plantarum strains from traditional butter made from camel milk in arid regions (Sahara) of Algeria.Lactobacillus plantarum strains previously isolated from the traditional butter made from camel milk (shmen) were evaluated for some probiotic criteria. Among 38 strains investigated for bile resistance, 14 were tolerant to 2% oxgall with survival percentages ranging from 69 to 75%. Out of these, only 4 strains (L. plantarum SH5, SH12, SH24 and SH32) were sufficiently resistant to pH 2.0 for 2 to 6 h incubation periods. Only crude extracts of L. plantarum SH12 and L. plantarum SH24 were inhibitory against Lactococcus lactis B8, the strain used as indicator. The antibacterial activity of crude extracts was completely lost after treatment with α-chymotrypsin and proteinase K. L. plantarum SH12 and SH24 strains were susceptible to penicillin G, oxacillin, vancomycin and clindamycin, but resistant to tetracycline and kanamycin. These strains showed rapid acidification activity (0.921 and 1.075 mmol/l of lactic acid, respectively), a good proteolytic activity (5.45 and 3.49 mg/l tyrosine at 72 h, respectively) and high survival percentage after freeze-drying. None of the strains produced polysaccharides or haemolysin in sheep blood.

The aims of this study were to determine the good conditions for fibers extraction from Retama monosperma young stems and their mechanical, physical and chemical characteristics. The fibers were extracted using a range of NaOH concentration from 1 to 16% in a period of treatment of 1 to 24 h, coupled with a physical treatment. For the evaluation of physico-mechanical characteristics, 200 samples were performed in the tensile test. The biochemical composition of the fibers was determined after separation of the parietal compounds. The results show that the best fiber yield was 11.51% obtained by a treatment of 14% NaOH for 8 h, followed by a physical treatment. The fibers biocomposition was 87.3% of cellulose, 7.5% of hemicelluloses and 1% of lignin. The Young's modulus was 13.3 GPa, tensile strength was 110 MPa and a density was 1.3 g/cm 3 . The average fiber length was 155.7 mm. The fibers yield and characteristics showed that R. monosperma plant may in future be suitable source for natural fibers.

Argania spinosa (L.) Skeels. (Argan) is tropical species, this plant is known bythese therapeutic and medecinal uses. For this purpose, we test antibacterial potential of leaf extracts of three Algerian population of Argan trees andwe evaluate the geographical distribution and solvent extraction effect onthe antibacterial activities. In first, Levels of total phenol content, total protein content of leaf extracts were determined by UV-spectrophotometer,secondary, The agar well diffusion method were used to determine enzymeactivities of proteins, antibacterial effect and the minimal inhibitory concentration (MIC) of extracts. The amounts of the phenol and protein concentrations in tested extracts were in ranged respectively between (118.83-147.17mg/mL) of Gallic acid equivalents (mg/mL) ) and (31.33-40.55mg/mL)of BSA (mg/mL), the crude fresh extract and crude protein extract showperoxidase activities, while protease activities were not found in ours extracts. Microbiological tests showed a high antibacterial potential of methanol extracts against tested bacteria ,Enterococcus faecalis (ATCC 29212) wasmost sensitive to methanol extracts (IZD: 17mm to 23.5),in opposite, aqueous extracts show weak antibacterial activities. Crude protein extracts hadnot antibacterial effects while crude fresh extracts were efficiency againstbacterial growth, biochemical enzyme tests revealed that crude extracts ofthe leaves show peroxidase activity wish may to increase antibacterial activities of crude extracts. The high activities of leaf Argan extracts were detected in Oran samples (littoral area) followed by Tindouf samples (arid area),this result confirmed positive relationships between geographical distribution of samples and their antibacterial activities.