Microbial Physiology

• Catabolism


  releases energy by oxidation of molecules or breaks down complex molecules
• Anabolism


  uses energy to synthesize macromolecules that make up the cell or building up aspect of macromolecules (DNA/RNA)
• catabolism and anabolism


  2 types of metabolism
• - Disease and food spoilage

  - Nitrogen cycle

  - Beverages and food

  - Sewage treatment

  - Drugs

  what are the impacts of microbial metabolism
• - respiration

  - fermentation

  - lipid catabolism

  - protein catabolism


  what are the important processes of microbial metabolism
• respiration


  glycolysis is followed by Krebs cycle, and electron transport chain which generates the most ATP
• respiration


  38 ATPs can be generated from 1 glucose molecule
• fermentation


  does not require Krebs cycle or ETC, and produces end products such as lactic acid or ethanol
• fermentation


  2 ATPs are produced from 1 glucose molecule
• lipid catabolism


  Lipids are first broken down into component fatty acids and glycerols by lipases
• lipid catabolism


  Each component can then enter the Krebs cycle
• protein catabolism


  Proteases and peptidases break down proteins into component amino acids
• protein catabolism


  AAs must undergo enzymatic conversion into substances that can enter the Krebs cycle
• - phototrophs

  - chemotrophs

  - autotrophs

  - heterotrophs


  what are the metabolic diversity
• Phototrophs


  light as energy source
• Chemotrophs


  redox of in/organic compounds
• Autotrophs


  self-feeders
• Heterotrophs


  feed on others
• take note


  Most medically important organisms are chemoheterotrophic, because typically, infectious organisms catabolize substances obtained from the host
• -physical requirements

  -chemical requirements


  what are the microbial nutritional
• temp

  pH

  osmotic pressure


  what are the physical requirements for microbial nutritional
• psychrophiles, mesophiles, thermophiles


  types of bacteria according to temperature
• Psychrophiles


  cold-loving bacteria
• Mesophiles


  moderate temperature bacteria
• thermophiles


  heat-loving bacteria
• 30°C apart


  Most bacteria grow within a limited range of temperatures yet the Min and max growth temps are only
• Optimum temperature


  temperature at which the species can best grow
• pH 6.5-7.5

  
  

  below pH 4


  when talking about pH most bacteria grow best between "blank", and few bacteria grow "blank"
• phosphate salts and peptones

  When bacteria are cultured in the lab, they often produce acids which interfere with their growth and chemical buffers such as "blank" and "blank" are included
• osmotic pressure


  Microbes obtain nutrients in solution from water
• Extreme halophiles

  Obligate halophiles

  Facultative halophiles


  what are the adaptations in osmotic pressure
• Facultative halophiles


  do not require high salt concentrations but can grow at concentrations up to 2%
• -carbon

  -nitrogen

  -sulfur

  -phosphorus

  -trace elements

  -organic growth factors

  -oxygen


  what are the chemical requirements for microbial nutritional
• Carbon


  Structural backbone of living matter; needed for all organic compounds that make up a living cell
• Nitrogen


  For forming the amino group of amino acids
• Sulfur


  For synthesis of sulfur-containing amino acids and vitamins such as thiamine and biotin
• Phosphorus


  For the synthesis of nucleic acids and phospholipids of the cell membrane; also in ATP
• Trace Elements


  Essential for some enzymes, sometimes as cofactors

  
  

  this also include iron, copper, molybdenum, and zinc
• Organic Growth Factors


  essential compounds not synthesized which are obtained from the environment

  
  

  this also include enzymes for vitamin synthesis, amino acids, purines, pyrimidines
• -Obligate aerobes

  -Facultative anaerobes

  -Obligate anaerobes

  -Aerotolerant anaerobes

  -Microaerophiles

  types of oxygen in chemical requirements