Salt Tolerance and pH Flashcards
T/F: Salt water is toxic to all microbes
F
T/F: Microbes are found in glaciers
T
T/F: All microbes require oxygen
F
T/F: Microbes are found in alkali pools
T
T/F: Microbes do not thrive in extreme environments such as hydrothermal vents and alkali pools.
F
Define neutrophile
Most microorganisms are neutrophiles, growing best in a pH of 7.0 and maintaining a pH in their cytoplasm between 6.8 and 7.4.
Define acidophile
The acidophiles will optimally grow in a pH between 0 and 5.5
Define alkaliphiles
which optimally grow at a pH between 8.0 and 11.5.
T/F: Very acidic or alkaline solutions compromise microbial respiration.
T
_____ optimally grow at a pH between 8.0 and 11.5.
Alkaliphiles
Define halotolerant v. halophiles.
Halotolerant microbes are able to survive at high salt concentrations but do not require these conditions for growth. Other microorganisms are considered halophiles because they require a high salt concentration for growth.
_____ solutions can lead to microbial cell swelling and rupture.
Hypotonic
T/F Microbes are only found growing at temperatures between 0°C and 100°C.
F
T/F Although oxygen is required for metabolism in many microbes, it is toxic to some species.
T
_____ solutions can lead to cell shrinkage and eventual death.
Hypertonic
_____ are microbes that require a high salt concentration for growth.
Halophiles
T/F most microbes prefer to grow in environments that are pH neutral and isotonic.
T
A _____ broth after incubation is a positive result when testing for pH and salt tolerances of microbes.
Turbid or cloudy
_____ is added to nutrient broth to adjust it to pH 9.
NaOH
T/F : A microbe that produces clear broths when tested at 7% and 15% NaCl is considered a halophile.
F
A microbe that only produces turbid broths in pH tests at pH 7 is considered a(n) _____.
Neutrophile
