Microbial Growth                                       Chapter 6

   I. Growth Requirements
      A. Physical Requirements
         1. temperature
               1) optimum growth temperature 
            a. psychrophils
            b. psychrotrophs
            c. mesophiles 
            d. thermophiles
            e. hyperthermophiles
         2. pH
            a. neutrophiles
            b. acidophiles
            c. alkalophiles
         3. osmotic pressure
               1) plasmolysis
            a. halophiles
            b. extreme halophiles
            c. facultative halophiles
      B. Chemical Requirements
         1. major elements
         2. trace elements
         3. oxygen
            a. obligate aerobes
            b. obligate anaerobes
            c. facultative anaerobes
            d. microaerophiles
            e. aerotolerant anaerobes

  II. Biofilms
      A. Quorum sensing
      B. Advantages

 III. Culture Media
         1. inoculum
         2. culture
         3. sterile
      A. Chemically defined
      B. Complex
      C. Special
      D. Selective & Differential
      E. Enrichment
      F. Storage

  IV. Growth
      A. Bacterial division
         1. binary fission
            a. logarithmic
         2. microbial growth
      B. Generation time
      C. Phases of growth
         1. closed system
            a. growth curve
               1) lag phase
               2) log phase
               3) stationary phase 
               4) death phase 
            b. colony growth
         2. continuous culture
      D. Measurement
         1. direct
            a. plate counts
               1) colony forming units
            b. pour and spread plate 
            c. filtration
            d. most probable number
            e. direct count
         2. indirect
            a. turbidity
            b. metabolic activity
            c. dry wt.