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Microbial Growth Binary Fission Growth Rate Generation Time
E. coli can double every 20 minutes Many Bacteria have 1-3 hr Generation Times
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Growth Curve Lag Phase Log Phase (Exponential) Stationary Phase
Death Phase Cryptic Growth
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Measuring Bacterial Growth
Total Cell Counts Direct Microscopic Counts Petroff-Hauser Counting Chambers
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Viable Counts Plate Counts
Spread Plate – Sample Spread on Solid Agar Plates
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Pour Plate Dilute Sample Suspended into Melted Agar
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Dilution
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Extinction Dilution MPN – Most Probable Number
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Turbidity Measurement
Spectrophotometer
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Culture Type Batch Culture Continuous Culture Chemostat
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Controlling Growth Temperature Minimum Optimal Maximum
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Temperature Ranges
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Cold Temperatures Psychrophile Psychrotolerant Freezing
Preserves Bacterial Cultures
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Other Factors pH Low pH Used to Preserve Foods Acidophiles
Alkaliphiles Buffers Used in Many Bacteriological Media
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Water Availability Drying Limits Bacterial Growth Halophiles
Osmophiles Xerophiles
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Oxygen Aerobe Anaerobes Facultative Microaerophile
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Growth Word List Growth Curve Lag Phase,
Exponential (log) Phase, Stationary Phase, Death Phase, Cryptic Growth Measuring Growth Total Cell Counts Direct Microscopic Counts Petroff-Hausser Counting Chambers Bacterial Growth Binary fission Growth rate Generation Time Exponential Growth Batch Culture
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Growth Word List 2 Controlling Growth Viable Count
Temperature Minimum, Optimal, Maximum Psychrophile (psychrotolerant) Mesophile, Thermophile Viable Count Plate Counts Spread Plate Pour Plate Dilution Extinction Dilution MPN – Most Probable Number Turbidity Measurements Continuous Culture Chemostat
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Growth Word List 3 Halophiles Hyperthermophile Osmophiles Freezing
Xerophiles Oxygen Aerobes, Anaerobes Facultative Microaerophile Hyperthermophile Freezing pH Acidophile Alkaliphile Buffers Water Activity
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