Microbiology-1 English (3. Week) PDF

MICROBIOLOGY-I GENERAL BACTERIOLOGY Assist. Prof. Dr. Halit ŞÜKÜR ([email protected]) Near East University Faculty of Veterinary Medicine Department of Microbiology  Anatomic Structure of the Bacteria 1- External structure 2- Internal structure Anatom...

MICROBIOLOGY-I GENERAL BACTERIOLOGY Assist. Prof. Dr. Halit ŞÜKÜR ([email protected]) Near East University Faculty of Veterinary Medicine Department of Microbiology  Anatomic Structure of the Bacteria 1- External structure 2- Internal structure Anatomic Structure of the Bacteria Internal Structure External  Cytoplasmic membrane Structure Cytoplasm Cellwall  Mesosom  Nucleotide Capsule  Ribosome Flagella  Cytoplasmic granules  Endospore Fimbriae (pilus) Pigment  Others (plasmid, phage, transposon, trace element) CYTOPLASMIC MEMBRANE CYTOPLASMİC MEMBRANE Under the cell wall, it is thin and generally of the same structure in bacteria It consists of two layers  It has a protein and phospholipid structure on the surface facing the periplasmic space and cytoplasm  The inner region contains the hydrophobic ends of the phospholipid  Membrane proteins exist in two forms: peripheral and integral.  CYTOPLASMIC MEMBRANE FUNCTION  It surrounds and protects to cytoplasm  It allows selective permeability and osmosis  It includes enzymes:  Cytochrome enzymes  Official enzymes in lipid synthesis  Official enzyme in cell wall synthesis  TCA enzymes  DNA replicase enzymes  Regulates the activities (hydrolytic and energy metabolism) of some enzymes  Participate in DNA replication  Constitutes the origin of mesosom  Plays a role in cell division and sporulation  CYTOPLASMIC MEMBRANE Selective permeability and transport -Passive transport (diffusion) Slow, no need for energy Play a role the concentration, electrical and pressure differences -Active transport The passage of large molecules Need for energy Carrier proteins are involved (enzymes, permease enzymes) E.g. : β-galactosidase system for lactose Phosphotransferase system acts in transition membrane Cytoplasm - It consist of liquid, organic and inorganic materials Mesosom - It is originated from cytoplasmic membrane - Vesicular or lamellar type and opens periplasmic space - Takes part in replication and some transport processes  Ribosome - It consists of RNA and protein - It sizes 70 S (50+30) - Numerous in which growing bacteria - It is involved synthesis of proteins and enzymes  Nucleotide - DNA, double-stranded helix  Cytoplasmic Granules Volutin (Babes-Ernst) granules - Structure in polymerized inorganic metaphosphate (polymetaphosphate) - Source of energy and phosphate - It is shown by Neisser and Albert staining  Lipid granules - The structure in lipid particles (polybetahydroxybutyrate) - The source of carbon and energy - It is shown with Sudan black  Polysaccharide granules - Structure of glucose homo or heteropolymer - The source of carbon and energy  Sulfur granules - It is found in sulfur bacteria -Source of energy  ENDOSPORE  When reduced food sources in their environment, some bacteria (e.g.; B. anthracis, B. subtilis, C. tetani, C. botulinum) occurs endospores which is resistant against physical (frost, dry, heat) and chemical effects (toxic substances) to protect themselves  Spores structures is too durable that even isolated from 3000 years soil samples  ENDOSPORE  Endospores can be oval or round shape  Spores may be appropriately sized to the diameter of the cell or may be greater than diamater of the cell (e.g.; Clostridium species, appear as the drumstick)  Endospores are stained by special staining methods such as Modified Ziehl-Neelsen or Spore staining  According to bacterial species endospores positions are shown in four ways :  Central  Subterminal  Terminal  Lateral  Locations of Endospores in Bacteria 1: Central endospor (smaller than the diameter bacillus) 2-5: Terminal endospor 3: Subterminal endospor 4: Central endospor (greater than the diameter bacillus) 6: Lateral endospor Clostridium botulinum (subterminal) Clostridium tetani (terminal) Bacillus anthracis (central)  ENDOSPORE An important and discriminative property of Bacillaceae family Aerobic – Bacillus spp. (B. anthracis, B. subtilis, B. cereus, B. megaterium) Anaerobic – Clostridium spp. (C. tetani, C. botulinum, C. perfringens, C. chauvoei, C. haemolyticum, C. novyi) Is not seen in cocci and spiral shaped bacteria Oval or round shaped, found in different places in bacterium Diameter of the spore can be smaller (Bacillus spp.) or larger (Clostridium spp.) than the bacterium If large, bacterium takes the shape of lemon, racket, hammer or shuttle In Bacillus anthracis spores appear in vitro and in aerobic conditions In Clostridium spp. spores appear both in vivo and in vitro, and in anaerobic conditions  Endospor Structure (from inside to out) -Core -Cytoplasm -Cytoplasmic membrane of spore -Cell Wall of spore -Cortex -Outer membrane (dipicolinic acid, DPA) -Exosporium  SPORULATION  Developing spores is called "Sporulation", and the developed spores' process to get vegetative forms are called "Germination". Endotrophic and exotrophic sporulation  In Bacillus spp. endotrophic sporulation  In Clostridium spp. exotrophic sporulation  SPORULATION  Sporulation needs carbon and energy  Amino acids and metal ions stimulate sporulation Poly-beta hydroxybutyric acid accumulation at one end or in the centre of bacterium and the cell becomes more refractile  This material is used as an energy and carbon source  Elongation of nuclear material towards one end  Location of nuclear material to the site of sporulation  Septum formation originating from mesosomes  Pre-sporulation  Formation of cortex by the accumulation of peptidoglycan, dipicolinic acid and Ca  Exosporium formation  Termination of sporulation within 5-13 hours SPORULATION  GERMINATION Development of vegetative forms from spores  Activation: spore is activated with activating elements such as oxygen, pH, heat, humid, nutrients  closely related with environmental conditions, breaking off disulphide bounds found in outer membrane and exosporium  Germination: amino acids, minerals and water enter the cell and activate lytic enzymes  Extension outward: new developed vegetative bacterium elongates within the spore and consequently protrudes from the spore  Development of vegetative form within 2 hours  PİGMENT When bacteria growth in general or specific solid medias, they form colonies with specific colors for their genus. Bacteria capable of reproduction under aerobic conditions have a larger number of species in terms of pigment formation compared to anaerobic ones. Pigments: They are divided into 2 basic groups as non-photosynthetic and photosynthetic ones.  PİGMENT Non-photosynthetic pigments Water soluble (Pseudomonas aeruginosa) Pyocyanin (blue-green color) Fluorecein (yellow-green color) Non-water soluble (Sarcina lutea (yellow), S. aureus (golden yellow), M.tuberculosis (yellow- red)) Photosynthetic pigments According to their structures; -Carotenoids - Anthocyanins - Melanins - Phenazine derivatives -Quinones - Pyrroles - Other  PLASMID Structure: Double stranded helix and circular DNA sequence Function: They give bacteria resistance to antibiotics as well as other special characters.  TRANSPOSONS (Tn) Structure: Short DNA sequences; They are found on the chromosome or plasmids of bacteria and mobile. Function: It plays a role in the resistance of bacteria to antibiotics.  BACTERIOPHAGES Structure: It consists of nucleic acid (DNA or RNA) and the surrounding protein-like capsid. Function: Creating a function in bacteria and causing their lysis. Some of them can integrate into bacterial DNA and become a continuation of the chromosome and replicate with it (prophage), they do not kill the bacteria.