Topic 3: growth dynamics

• Microbial growth


  Increase in cellular components = increase cell number
• Binary fusion


  Process of cell division
• Microbial growth process


  1. DNA replication

  2. Cell elongation "synthesis"

  3. Septum formation

  4. Completion of septum "cell wall"

  5. Cell separation
• Divisome


  Series of proteins = septum in cell division
• Fts proteins essential for cell division

  • FtsZ- forms firings around centre – chitin
  • FtsA – connects FtsZ to mem cyto
  • FtsL – links peptidogyclan sheets
  • FtsK – genome segement
  • Lipa – anchor connect FtsZ to cyto mem
  • MreB – determine rod shape
• Cell wall growth contains

  • Bactopernol
  • Pedigyclogan
  • NAG and NAM
  • Enzymes
• 3 population growth of prokaryotes

  • Growth rate
  • Generation time
  • Expo growth
• Batch culture


  Closed system with fixed volume

  Conditions constantly changes
• 4 phases of population growth


  • Lag phase – no increase, starting to use medium
  • Expo phase – doubling occurs
  • Stationary parade – no increase and competition occurs
  • Death phase – cells expo die
• Generation time


  Dependent on growth and incubation medium
• Diauxic growth


  Grow 2 substrates and curve looks like an 'S'
• Microbial generation/doubling time in nature is longer than in lab due to lab having stable conditions and plentiful supply of nutrients
• Bactoprenol


  Hydrophobic molecules – carriers peptidocylan across cytoplasmic membrane

  Interacts with transglycosulase – insert them into space produced by autolysin
• Microbial growth


  Increase in cellular components = increase cell number
• Binary fusion


  Process of cell division
• Microbial growth process


  1. DNA replication

  2. Cell elongation "synthesis"

  3. Septum formation

  4. Completion of septum "cell wall"

  5. Cell separation
• Divisome


  Series of proteins = septum in cell division
• Fts proteins essential for cell division

  • FtsZ- forms firings around centre – chitin
  • FtsA – connects FtsZ to mem cyto
  • FtsL – links peptidogyclan sheets
  • FtsK – genome segement
  • Lipa – anchor connect FtsZ to cyto mem
  • MreB – determine rod shape
• Cell wall growth contains

  • Bactopernol
  • Pedigyclogan
  • NAG and NAM
  • Enzymes
• 3 population growth of prokaryotes

  • Growth rate
  • Generation time
  • Expo growth
• Batch culture


  Closed system with fixed volume, Conditions constantly changes
• 4 phases of population growth

  • Lag phase – no increase, starting to use medium
  • Expo phase – doubling occurs
  • Stationary parade – no increase and competition occurs
  • Death phase – cells expo die
• Generation time


  Dependent on growth and incubation medium
• Diauxic growth


  Grow 2 substrates and curve looks like an 'S'
• Microbial generation/doubling time in nature vs lab

  Longer in nature due to lab having stable conditions and plentiful supply of nutrients
• Bactoprenol role

  Hydrophobic molecules – carriers peptidocylan across cyto mem, interacts with transglycosulase – insert them into space produced by autolysin