Microbial Growth and Environmental Requirements

These flashcards cover key vocabulary and concepts related to microbial growth, environmental requirements, and related processes.

Minimum Growth Temperature

The lowest temperature at which a microorganism can grow and metabolize.

Optimum Growth Temperature

The temperature at which an organism exhibits the highest rate of growth.

Maximum Growth Temperature

The highest temperature at which an organism can still grow and metabolize; temperatures above this lead to protein and cellular damage.

pH

A measure of the acidity or alkalinity of an environment; most bacteria thrive in a neutral pH range of 6.5 to 7.5.

Hypertonic Environments

Environments with a higher concentration of solutes outside the cell, causing water to leave and leading to plasmolysis.

Extreme Halophiles

Microorganisms that thrive in extremely salty environments, with high salt concentrations.

Psychrophiles

Organisms adapted to cold temperatures, often found in polar regions.

Mesophiles

Microorganisms that thrive best at moderate temperatures, typically around 30-37°C.

Thermophiles

Microorganisms that grow optimally at high temperatures, often found in hot springs or compost.

Autotrophs

Organisms that utilize inorganic carbon sources, primarily carbon dioxide, for growth.

Obligate Aerobes

Microorganisms that require oxygen for survival and cannot grow without it.

Facultative Anaerobes

Microorganisms that prefer to grow in the presence of oxygen but can survive without it.

Biofilm

Communities of microorganisms that aggregate in a self-produced extracellular matrix, providing enhanced resistance to environmental stresses.

Quorum Sensing

Communication process among bacteria in biofilms that involves the secretion of signaling molecules to coordinate behaviors.

Culture Medium

A nutrient-rich solution specifically designed for growing microorganisms under laboratory conditions.

Selective Media

Media designed to suppress unwanted microbial growth while promoting specific microorganisms.

Differential Media

Media used to distinguish between microbial species based on their metabolite production.

Binary Fission

The predominant method of bacterial reproduction, where a single cell divides into two daughter cells.

Lag Phase

An initial phase of microbial growth characterized by metabolic activity without immediate increase in cell numbers.

Log Phase

A phase of microbial growth where there is pronounced cell division and population size increases exponentially.

Stationary Phase

The phase where growth stabilizes due to nutrient depletion and accumulation of waste leading to equal rates of cell formation and death.

Death Phase

The phase characterized by a decline in cell population where mortality exceeds reproduction.