Effects on Bacterial Growth

Aerotolerant anaerobe

• high density throughout tube

• Can grow in presence of oxygen

Facultative anaerobe

• high density at top of tube and low density growth throughout tube

• Prefers oxygen but can grow without it

Strict anaerobe

• High density at bottom of tube

• Cannot grow in presence of oxygen

Strict aerobe

• High density at bottom of tube

• Cannot grow without oxygen

Microaerophile

• High to low density clump of growth within the middle to top half of tube

• Can tolerate varying concentrations of oxygen presence

Thermophiles

• Ideal conditions above 40°C

Psychotrophs

Ideal conditions between 0°C to 30°C

Mesophiles

Ideal conditions between 15°C to 45°C

Psychrophiles

Ideal conditions below 20°C

Extreme Thermophiles

Ideal conditions between 65°C to 110°C

Neutrophiles

Ideal pH between 5.5 and 8.5

Alkaliphiles

Ideal pH above 8.5

Acidophiles

Ideal pH below 5.5

Osmotolerant

Can grow in wide range of salt concentrations

Extreme Halophile

Grow best in salt concentration from 15% to 25%

Halophile

Grow best in concentration of 3% or higher