Tài liệu Microbiology

Microbiology Technical Service Field Service Quality Assurance Microbiology Microbiology is the study of organisms which are so small that they can only be seen with the aid of a microscope. Size is measured in micrometer. 5 µm 1 µm = 0,001 mm Technical Service Field Service Quality Assurance Micro-organisms Groups Protozoa Algae Fungi - Yeast - Mould Bacteria Viruses Range of Size 2 - 200 mm 1 mm - a few meters 5 - 10 mm 2 - 10 mm by meters 0,5 - 5 mm 0,015 - 0,2 mm Technical Service Field Service Quality Assurance Micro-organisms in the Laboratory cfu, colony forming unit Technical Service Field Service Quality Assurance Microbial Loads Locality CFU/hour 2 and100cm Mibi Picture 16 240 40 Gram pos. bacteria dominate 280 320 A lot of gram neg. bacteria 150 Moulds dominate In-doors: Dry environment Office far from people Office close to people Corridor people passing In-doors: Wet environment Toilets Cleaning room Out-doors environment Lawn far from people Technical Service Field Service Quality Assurance Shapes of Bacteria Spherical Rods Curved or Spiral c ) b) a ) d ) Technical Service Field Service Quality Assurance The Bacterial Cell - Basic Structures Cell wall(1) Cell membrane(2) Chromosome(3) 1 2 3 4 Cytoplasm(4) Technical Service Field Service Quality Assurance Bacterial Cell - Structures Cell wall Pili Cell membrane Cytoplasma with ribosomes Capsule Granule Mesosome Chromosome Flagellum Technical Service Field Service Quality Assurance Bacteria : Function of Cell Structures CELL WALL ◊ giving the cell its specific shape ◊ protects the cell against high pressure and mechanical forces CELL MEMBRANE ◊ acts as osmotic barrier ◊ active transport of nutrients and metabolites CYTOPLASM ◊ place of production CHROMOSOME ◊ carrier of genetic information Technical Service Field Service Quality Assurance Bacteria : Grampositive and Gramnegative mainly peptidoglycan s lipopolysaccharides cytoplasm peptidoglycans cytoplasm cellmembrane Technical Service Field Service Quality Assurance Gram+ and Gram- Bacteria Gram-positives Gram-negatives ∗ Micrococcus ∗ Pseudomonas ∗ Streptococcus ∗ Coliforms ∗ Staphylococcus ∗ Salmonella ∗ Lactobacillus ∗ Shigella ∗ Corynebacterium ∗ Serratia ∗ Actinomyces ∗ Yersinia ∗ Bacillus ∗ Vibrio ∗ Clostridium Technical Service Field Service Quality Assurance Bacterial Spores Vegetative cells Multiplication Sporulating cell The Dormant Spore Outgrowth Germination Mature spore Core Cortex Exosporium Membrane Coats Technical Service Field Service Quality Assurance BERGEY´S MANUAL OF Systematic Bacteriology Classification and Identification of Bacteria including ecology, enrichment, isolation and preservation Technical Service Field Service Quality Assurance BERGEY’S MANUAL OF DETERMINATIVE BACTERIOLOGY 8th edition 1974 • 19 Parts • 48 Families • 245 Genera • 2000 Species Technical Service Field Service Quality Assurance BERGEY’S MANUAL OF DETERMINATIVE BACTERIOLOGY Ninth Edition 1994 Identification of Bacteria 35 Groups 550 Genera 4 500 Species Technical Service Field Service Quality Assurance Multiplication of bacteria 1 ⇒ 2 ⇒4 ⇒8⇒16⇒32… 20 ⇒21⇒22⇒23⇒24⇒25… Nt = N0 x 2n t n= g t lg Nt = lg N0 + g x lg 2 g = generation time, i.e. the time for duplication n = number of generations t = incubation time, i.e. the time for growth N0 = number of bacteria at time zero Nt = number of bacteria at time t Technical Service Field Service Quality Assurance Generation Time temp.(oC) Bacterium medium g(min) E. coli E. coli milk 37 glucose+minerals 37 12 90 Streptococcus lactis milk 37 26 Lactobacillus acidophilus milk 37 75 Technical Service Field Service Quality Assurance as Ph e Log Pha se Stationary Phase ath De Log No of Bacteria The Bacterial Growth Curve Time Lag Phase Technical Service Field Service Quality Assurance Fungi Yeast Mould spores sporophore mycelium budding hypha Technical Service Field Service Quality Assurance Fungal Spores Sexual Asexual chlamydospores conidiospores zygospore ascospores sporangiospores basidiospores Technical Service Field Service Quality Assurance