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• Psychrophiles


  Cold loving bacteria
• Mesophiles


  Organisms that cause diseases in humans; moderate – temperature growing microbes
• Thermophiles


  Heat loving bacteria
• Hyperthermophiles


  Heat resistant microorganisms; Can tolerate very high temperatures
• Temperature ranges


  • 0°C to 20°C
  • 10°C to 45°C
  • 40°C to 70°C
  • 75°C to 113°C
• Optimal temperatures


  • 15°C
  • 35°C
  • 60°C
  • 80°C
• Acidophiles


  Grow in an acidic medium (pH <6)
• Neutrophiles


  Grow in a neutral medium 6.5-7.5 (pH 6 to 8)
• Alkalinophiles


  Grow in an alkaline medium 8.4-9.0 (pH >8)
• Osmophiles


  Organisms that require high osmotic pressure in order to survive
• Halophile


  Requires high levels of salt; can survive in salt water (marine) environment
• Autotrophs


  Microorganisms that utilize inorganic compounds(e.g., carbon dioxide) and inorganic salts as their sole carbon source
• Photolithotrophs


  Derive energy from light
• Chemolithotrophs


  Energy derived from oxidation of inorganic substances and molecules
• Heterotrophs


  Organisms that make use of organic substances like sugars or glucose as their carbon source
• Obligate aerobes


  Organisms that require an absolute requirement for oxygen
• Microaerophilic microbes


  Organisms that grow best at lower oxygen tension
• Obligate anaerobes


  Oxygen is toxic or fatal for the organism
• Facultative aerobes


  Organisms capable of growth under both aerobic and anaerobic environment
• Aerotolerant anaerobes


  Does not grow well, but survives in the presence of atmospheric (free) oxygen
• Capnophiles


  Some organisms that may require the addition of carbon dioxide (5-10%) to enhance their growth
• Growth cycle


  1. Lag phase

  2. Log phase / Exponential phase

  3. Stationary phase

  4. Death/ Decline phase
• Lag phase


  Little or no multiplication but enzymes are very active; a period of adjustment and adaptation
• Log phase / Exponential phase

  Organisms grow at maximum; most metabolically active
• Stationary phase


  Growth ceases because nutrients are exhausted or toxic metabolic products have accumulated
• Death/ Decline phase


  Rate of cell division stops completely
• Microbial ecology


  Interrelationships between microorganisms and the world around them
• Symbiosis


  Living together or close association of two dissimilar organisms

  
• Types of symbiotic relationships


  • Neutralism
  • Commensalism
  • Mutualism
  • Parasitism
• Neutralism


  Neither symbiont is affected by the relationship
• Commensalism


  Beneficial to one symbiont, no consequence to the other organism (neither harmed nor benefited)
• Mutualism


  Beneficial to both symbionts
• Parasitism


  Beneficial to one symbiont, detrimental to other symbiont
• Biosafety cabinet classes


  • Class I
  • Class II
  • Class III
• Class I biosafety cabinet


  Open front. Utilizes a vacuum that pulls the air towards it. Provides minimal personnel protection, does not protect work surface.
• Class II biosafety cabinet


  Laminar flow biosafety cabinet with variable sash opening. Sterilizes the air inside and the air coming out. Most commonly used in hospital micro labs, provides protection for worker and work surface.

  
• Class III biosafety cabinet


  Affords the most protection. Equipped with glove compartments that confer minimum exposure to biological specimen. Provides maximum protection.
• Biosafety levels


  • Level 1 (Minimal risk)
  • Level 2 (Moderate risk)
  • Level 3 (High risk)
  • Level 4 (Extreme risk)
• Biosafety level 1


  Those not known to cause disease in healthy adults, used for laboratory teaching
• Biosafety level 2


  Being sought in clinical specimens, commonly isolated in association with disease