Microbiology I

Main purpose: to provide the basic knowledge of the microbial world, that are necessary for being able to face the successive disciplines of microbiological character and those to they correlated, and to deepen the main microbial groups involved in the production, transformation and conservation of foods. 1-The microbial world and its members. Prokaryotes: cell structure and function and comparison with the more complex eukaryotic cell. Morphology of bacteria, molds and yeasts (regarding their reproduction). Microbial nutrition: carbon and nitrogen sources, growth factors. Cultural requirements: effect of temperature, pH, water availability and oxygen on microbial growth. Metabolism: catabolism and anabolism. The most important modes of energy generation: aerobic and anaerobic respiration, fermentation. The major mechanisms of energy-linked transport of nutrients into the cell (2 CFU). 2-Microscopy: phase contrast microscope, magnification and resolution, sample preparation, staining procedures. The sterility concept and sterilization (heat, radiation, filter sterilization). Laboratory culture of microorganisms: isolation techniques for the obtainment of pure cultures, maintainment conditions, liquid, semi-solid or solid culture media, classes of culture media (chemically defined, complex, selective) and their preparation. Growth cycle of populations, and measurement of growth (viable count, dilutions, direct microscopic counting procedure, measurement of cell mass and turbidity) (2CFU) 3-I Viruses and bacteriophages. General properties, replication cycle, lysogeny, temperate bacteriphages. Genetic recombination (transformation, transduction and conjugation), molecular basis of mutation. Microbial evolution and taxonomy: genus, species and strain concept. Bacterial identification: phenotypic and genotypic analyses. The major bacterial groupes involved in production and conservation of foods. Classification and identification of yeasts and molds involved in food industry. (2 CFU)