Chapter 7

• Binary fission

  the process in where a prokaryotic cell turns into 2 cells.
• Microbial growth

  Is defined as the number of cells increasing, cell size increases and components are growing.
• Psychrophile


  Optimal temperature is <15℃.
• Psychrotolerant

  Optimal temperature is 15-30
• Mesophile

  Optimal temperature: 20-40
• Thermophile

  Optimal temperature:>45
• Extremothermophile

  Optimal temperature: 80-121
• Optimal temperatures

  results in the most amount of growth
• Min and maximum

  Little to no growth
• Bacterial growth pattern

  Occurs in an exponential pattern, so 1 goes to 2, 2 goes to 4 and up and up. A log scale allows you to better visualize the growth compared to a linear scale which will have to be much bigger and have a scale that writes each individual number instead of writing log^1 or log ^10.
• Lag phase

  Little to no growth is occurring, the bacteria is adjusting, getting familiar to the environment and repairing damage from the previous environment the bacteria were in.
• Exponential phase

  Is where exponential growth occurs, the bacterial cells will grow and divide, the cells will grow at the maximal rate but at a steady rate.
• Stationary phase

  The number of growth of bacteria is equal to the amount of bacterial cell death. So the number of bacteria is staying constant.
• Death phase


  There is no more bacterial growth occurring. So the number of bacteria cells will decrease.
• Oxygens effect on growth

  Plays a important role in the the structural and enzymatic functions of the cell. Is a powerful oxidizing agent that can cause damage to nuclic acid, protiens and lipids.
• Temperature effect on growth

  Bacteria can only go in certain temperature ranges, if not within that range, growth cannot occur. Microbes cannot regulate their own temperature so they rely on the environment's temperature.
• pH effect on growth

  The cytoplasm is always maintained at a neutral pH. If the pH is not maintained the enzymes and cellular structures can be damaged.
• Salt effect on growth


  how much water goes into the cell and out of the cell. If too much water goes into the cell the cell will burst. The cell can become dehydrated if there is too much salt.
• Radiation


  Cells can be damaged by toxic oxygen that is produced by light they are nonphotosynthetic. Ultraviolet and ionizing waves can damage the cell as well.
• Hydostatic Pressure


  Pressure that a cell is not habited to can cause a rupture.
• Moisture

  Water is needed for all cells in order to digest micromolcules and for enzyme function.
• Macronutrients

  Carbon,Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur and water. Proteins, lipids, carbs and nucleic acids.
• Micronutrients


  Trace elements such as Calcium, magnesium, manganese, chlroide, salt, iron, and cobalt.
• Growth factors

  Compounds that must be supplied in media such as vitamins and bases.
• Anaerobe

  Do not require oxygen so they will live on the bottom of the ocean.
• Aerobe

  Do require oxygen to live, they can live in bodies of water where thre is dissolved ocean and can also live on land with atmospheric oxygen.
• obligate halophiles

  Live in hypertonic environments such as salt lakes, pools of evaporated seawater and solar salterns.
• Facultative halophiles


  Can live in places with high salt concentrations or low salt concentrations.
• VBNC

  means viable not culturable so it is not able to grow because of it's conditions but will be able to grow if it has the right conditions.
• Problems with VBNC

  cannot be grown in normal conditions they are hard to detect and identify. They can cause harm but not be able to be identified.
• Ways to quantify microbial numbers

  Diluting and plating to back calculate, count by filtration, cycomter and stain, turbidity.