Antimicrobial and antifungal activities of Lactobacillus curvatus strain isolated from homemade Azerbaijani cheese.

The aims of this study were to characterize inhibitory activity spectra, some probiotic properties and safety of Lactobacillus curvatus A61 for its future application in production of fermented foods. The studied strain was isolated from traditional homemade cheese manufactured in Azerbaijan. The cell-free supernatant of culture of Lb. curvatus A61 inhibited the growth of tested LAB, as well as of Listeria monocytogenes and Bacillus cereus strains. The strain presented antifungal activity and inhibited the growth of Cladosporium and Fusarium ssp. during co-cultivation on agar media. PCR amplification with specific primers revealed the presence of curvacin A encoding gene in Lb. curvatus A61. Bacteriocin produced by the studied strain was heat stable and active in a broad pH range, and in the presence of Triton X-20, Triton X-80, Triton X-100, ß-mercaptoethanol, Na-EDTA, SDS and NaCl. The mode of action of bacteriocin against selected indicator strains was found to be bacteriostatic. Lb. curvatus A61 was resistant to physiological concentrations of bile salts and showed high auto-aggregation ability, as well as co-aggregation ability with pathogenic L. monocytogenes strains. It was sensitive to chloramphenicol, penicillin, tetracycline, ciprofloxacin and vancomycin, but resistant to ampicillin and gentamicin.

Combined proteomic and molecular approaches for cloning and characterization of copper-zinc superoxide dismutase (Cu, Zn-SOD2) from garlic (Allium sativum).

Superoxide dismutases (SODs; EC 1.15.1.1) are key enzymes in the cells protection against oxidant agents. Thus, SODs play a major role in the protection of aerobic organisms against oxygen-mediated damages. Three SOD isoforms were previously identified by zymogram staining from Allium sativum bulbs. The purified Cu, Zn-SOD2 shows an antagonist effect to an anticancer drug and alleviate cytotoxicity inside tumor cells lines B16F0 (mouse melanoma cells) and PAE (porcine aortic endothelial cells). To extend the characterization of Allium SODs and their corresponding genes, a proteomic approach was applied involving two-dimensional gel electrophoresis and LC-MS/MS analyses. From peptide sequence data obtained by mass spectrometry and sequences homologies, primers were defined and a cDNA fragment of 456 bp was amplified by RT-PCR. The cDNA nucleotide sequence analysis revealed an open reading frame coding for 152 residues. The deduced amino acid sequence showed high identity (82-87%) with sequences of Cu, Zn-SODs from other plant species. Molecular analysis was achieved by a protein 3D structural model.