Microbiology Bio 205

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Microbiology Bio 205

• Test 1
• Dr. Rhoads

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Introduction

• A microorganism is?
• You cant see it, at least without a microscope
• Can live as independent cells (?)
• A critter in one of the 3 microbial kingdoms
• So, what is a kingdom anyway?
• Carl Linnaeus Binomial Hierarchical system
• 7 levels of hierarchy
• 2 names Genus species or Genus species

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Binomial Hierarchical systembut things are
changing

• 7 levels of organization
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• species

• 5 Kingdoms

e u k a r y o t e s
plants animals
m i c r o b i a l
fungi protista
prokaryote
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Classification

• Fungi Eukaryotes saprophytes chitin cell
  walls
• Molds filamentous
• hyphae
• 1 saprophytes
• Ex Histoplasma
• Yeast single celled
• budding
• fermentation
• pleomorphic
• Ex Candida
• Mushrooms microbes?

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Classification

• Protista Eukaryotes odds-n-ends
• Algae photosynthetic
• uni multicellular
• cellulose
• Kelp microbes?
• Diatoms silicone crystals
• Protozoa respiration unicellular
  wall-less
• Ex Entamoeba, Plasmodium

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Classification

• Prokaryotes vs Eukaryotes
• Small 0.1 10 microns vs 10-100 microns
• http//learn.genetics.utah.edu/content/begin/cell
  s/scale/
• Simple no organelles
• Cell division binary fission vs mitosis
  meiosis
• Ribosomes 70 S vs 80S
• DNA E mulitple linear diploid chromosomes
  histones
• P DSCCC haploid chromosome plasmids

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Classification

• Prokaryotes peptidoglycan
• Bacteria metabolic diversity!!!
• Archae genetically old extreme
  environments
• Thermophiles
• Ex Pyrodictium brockii
• Acidophiles
• ex Thiobacillus ferrooxidans
• Halophiles
• Cyanobacteria ie. blue-green algae
  photosynthetic
• ex Anabaena

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Classification

• Animals helminths
• arthropods
• Viruses what are they?
• what do they do?
• size nanometers 10-9 meters

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Roles of microbes

• Disease prevention
  1. competition food, other
  necessities, receptor binding 2. vaccines
  what is it? what do we need to make them? 3.
  antibiotics what do they do? where do they
  come from?
• Food
• a) good
• Lactose fermentation in dairy products ? lactic
  acid
• Ex Lactobacillus, Propionibacterium, etc.
• Vegetable pickling (kraut, kimchi, etc) ? lactic,
  acetic, etc.
• Ex Leuconostoc, Lactobacillus, etc.
• Amylases Aspergillus oryzae (koji)
• b) bad spoilage food poisoning
• vs canning, freezing, drying,
  preservatives Ex
  Staphylococcus aureus, Clostridium botulinum

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Roles of microbes

• Agriculture / ecology
• Nutrient cycle cellulose ? glucose PO4 cycle,
  etc. 1st steps bacteria then protozoa or fungi
  then
• Photosynthesis CO2 ? glucose AND O2
  evolution algae cyanobacteria
• Nitrogen fixation N2 ? NO3
  Ex Frankia,
  Rhizobium
• Denitrification a problem NO3 as TEA ? NH3
  Pa Paracoccus denitrificans

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Roles of microbes

• Biotechnology
• Insulin
• Better, safer vaccines
• Agriculture BT cotton Bacillus thurengiensis
• high lysine corn
• Bioremediation
• Oil spills
• Other
• AND LOTS MORE!!!
• Ch 2 cell chemistry review on-line

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Chapter 4 Cell Biology

• Capsule other names attachment
  anti-phagocytosis
• functions virulence factor
• who has them?
• Strep mutans, S. sanguis
• Klebsiella pneumoniae
• Flagella motility chemotaxis
• a) Eukaryote 9 2 microtubule arrangement
• like actin myosin mechanism
• b) Prokaryote rigid homogeneous flagella
• rotates like a propeller
• see images ?

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Prokaryotic flagella
Polar monotrichous E. coli Lophotrichous -
Pseudomonas Peritrichous - Proteus
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More cell structure

• Fimbriae / pili
• Fimbriae specific attachment Neisseria
  gonorrhoea urogenital epithelium
  Enteropathogenic E. coli colon mucosa
• Pili conjugation between competent cells
• plasmid DNA transfer

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continued

• Cell wall (plus membrane(s) envelope)
• Functions rigid shape protection BUT
  porous
• osmotic stability in hypotonic environments
• hypertonic plasmolysis
• hypotonic possible plasmoptysis
• Composition
• Algae cellulose
• Fungi chitin
• Bacteria peptidoglycan
• structure polysaccharide tetrapeptide
  bridges
• Gram positive thick layer
• Gram negative thin layer
• Mycoplasma?

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continued

• Resistance / susceptibility (to antibiotics, or
  other things)
• Gram positive tough but Penicillin lysozyme
  sensitive
• Gram negative just the opposite
• Gram negative envelope
• outer membrane endotoxin (Lipid A)
• pyrogen
• composed of lipopolysaccharide
• Functions porins minimal effect on solute
  transport anti-phagocytosis
• Endotoxin (vs exotoxin) local vs systemic
  pathology more mild, less
  specific
• heat protease labile

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• Cytoplasmic membrane ALL cells have them
• Structure triglycerides a) glycerol b) 3
  fatty acids VS phospholipids
• lipid bilayer
• fluid mosaic model
• Membrane structure determine its function ?

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• Cell membrane functions
• basis equilibrium entropy diffusion
  polarity
• regulates transport of solute
• selectively permeable
• controls diffusion of polar solute on basis
  of
• size charge polarity
• STRUCTURE DETERMINES FUNCTION!

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continued

• Endospores Bacillus Clostridium
• Why are cells small? SA V
• --------------------------------------------------
  ------
• Factors affecting microbial growth
• - Temperature mesophiles vs thermophiles
  
• Bacillus stearothermophilus
• - pH H acid base pH scale
  buffer
• neutralophiles virtually all pathogens
• acid tollerant Staph, Lactobacillus,
  more
• - AW solute in water sugar, salt, other
  
• food preservation honey, cured
  meat, etc.
• Fungi Staph, Lactobacillus,
  Leuconostoc

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continued

• Oxygen requirements respiration vs fermentation
• superoxide dismutase 2 O-2 2 H ?
  H2O2
• catalase 2 H2O2 ?
  2 H2O O2
• Obligate aerobes aerobic respiration
  Pseudomonas
• Microaerophiles not much different
  Campylobacter
• Facultative (anaerobes) both most pathgens
  Staph
• Aerotollerant anaerobes fermentation Strep
• Obligate anaerobes O no growth
  Clostridium
• O no survival Methanogens