Microbial Growth and Environmental Influences

Flashcards covering key concepts related to microbial growth and environmental influences.

Biofilm

A structured community of microorganisms embedded in a matrix of extracellular polymeric substances.

Binary Fission

The most common method of cell replication in bacteria, where one cell divides into two daughter cells.

Quorum Sensing

The process by which bacteria communicate and coordinate their activities through the release and detection of signaling molecules.

Generation Time

The time it takes for a population of bacteria to double in number, often associated with binary fission.

Obligate Aerobes

Microorganisms that require oxygen to grow and cannot survive without it.

Obligate Anaerobes

Microorganisms that cannot grow in the presence of oxygen and depend on anaerobic respiration.

Facultative Anaerobes

Microorganisms that can grow in both the presence and absence of oxygen.

Microaerophiles

Microorganisms that require low levels of oxygen (1%-10%) for growth.

Acidophiles

Microorganisms that thrive in acidic environments, typically with a pH below 5.5.

Halophiles

Organisms that require high salt concentrations for growth.

Psychrophiles

Microorganisms that grow optimally at low temperatures, typically below 15 °C.

Thermophiles

Microorganisms that thrive at higher temperatures, typically between 50 °C and 80 °C.

Hyperthermophiles

Microorganisms that grow optimally at extremely high temperatures, often above 80 °C.

Catalase

An enzyme that catalyzes the conversion of hydrogen peroxide into water and oxygen, helping to detoxify reactive oxygen species.

Spectrophotometer

An instrument used to measure the turbidity or absorbance of a bacterial culture, providing an indirect estimate of cell density.

Coulter Counter

An electronic device that counts cells by measuring changes in electrical resistance as cells pass through a small aperture.

Viable Plate Count

A method for estimating the number of live bacteria in a sample by counting colonies formed on a solid medium.

Membrane Filtration Technique

A method used to concentrate microorganisms from a liquid sample by filtering it through a membrane with a specific pore size.

Most Probable Number (MPN) method

A statistical method used to estimate the number of viable microorganisms in a sample, often used in water testing.