bacterial requirements temperature and oxygen. measurement of microbial growth cfu direct viable...

Bacterial Requirements

Temperature and Oxygen

Measurement of Microbial Growth

CFU Direct

Viable Plate Counts Serial Dilutions Pour Plate Spread Plate

Membrane Filtration Counting Chamber MPN (fecal, H20, food)

Indirect Turbidity Metabolic activity

Metabolic Classifications

Temperature Oxygen requirements pH Pressure Radiation

Growth Curve Labeled Phases Lag phase

Adaptive Start metabolism 1-3 days

Log phase Generation time doubles Most metabolically active

Stationary phase Growth = death

Death phase Requirements decrease Possible spore formation

Temperature Requirements

Temperature Experiment

4 TSA plates Label

Temperature 4 different settings

Wheel spoke pattern 5 Bacteria

4 SAB broth/Durham tube Temperature

4 different settings S. cerevisiae

Anaerobic Culture Methods

Oxygen Requirements

Obligate Aerobes Microaerophiles Aerotolerant anaerobes Obligate Anaerobes Facultative Anaerobes Capnophiles

BHI deeps

Brain/Heart infusion Melt Label

BHI Organism

Inoculate Pipette or loop Roll tube to distribute

Ice Bath Incubate @ 37°C

Fluid Thioglycollate Broth

Sodium thyioglycollate Reduction (redox) Pink if oxidized

Label tubes Thio Organism

Inoculate with loop Incubate @ 37°C

Gas Pack Jar: CO2 anaerobic System

NaHCO3, NaBH4

H2O added to envelope toProduce H2 and CO2

H2 + O2 => H2O

TSA agar plate4 quadrantsLabel bacteriaLabel O2

Aerobic / Anaerobic Lab Test Results

aerobe FA aerotolerant anaerobe

Physical Requirements: Temperature Psychrophile

Unsaturated FA in cell membrane

Cold temperatures Psychrotroph (facultative

psychrophiles) Refrigeration Room temperature

Mesophile Warm Blooded Animals

Thermophile/Hyper- Saturated FA in cell

membrane

Bacterial Examples: Temperaturepsychrophile psychrotroph

mesophile thermophile

E coli

mold Vibrio

Archaea

Oxygen Requirement Classification

BHI results

Thio Tubes

Bacterial Examples of O2 Groups Obligate Aerobes

Pseudomonas Microaerophiles

H. pylori Aerotolerant aerobes

Streptococcus Lactobacillus

Obligate Anaerobes Clostridium

Facultative Anaerobes E. coli Stapylococcus

Capnophilic Campylobacter

E coli

Staph

pH Groups

Acidophile Bacillus acidocaldarius Lactobacillus acidophilus

Neutrophile E. coli Staphylococcus aureus

Akaliphile Streptococcus

pneumoniae Nitrobacter sp.

Questions?