Microbial Ecology and Growth

These flashcards cover key vocabulary and concepts related to microbial ecology and growth, essential for understanding the subject and preparing for exams.

Bioelements

Basic requirements for life, including carbon, hydrogen, oxygen, phosphorus, potassium, nitrogen, sulfur, calcium, iron, sodium, chlorine, and magnesium.

Essential nutrients

Substances (elements or compounds) that an organism must obtain from external sources.

Macronutrients

Nutrients required in large quantities that play principal roles in cell structure and metabolism, such as proteins and carbohydrates.

Micronutrients

Trace elements required in small amounts, involved in enzyme function and protein structure maintenance, like manganese, zinc, and nickel.

Organic nutrients

Nutrients that contain carbon and hydrogen atoms, typically derived from living things, including methane, carbohydrates, lipids, proteins, and nucleic acids.

Inorganic nutrients

Atoms or molecules that contain a combination of atoms other than carbon and hydrogen, such as metals, salts, gases, and water.

Heterotroph

An organism that must obtain carbon in an organic form produced by other living organisms.

Autotroph

An organism that uses CO2, an inorganic gas, as its carbon source and is not nutritionally dependent on other living things.

Growth factors

Essential organic nutrients that must be provided for survival because the organism cannot synthesize them.

Psychrophiles

Microorganisms that have an optimum growth temperature below 15°C.

Mesophiles

Microorganisms that have an optimum growth temperature between 20°C-40°C, and most human pathogens belong to this group.

Thermophiles

Microorganisms that have an optimum growth temperature greater than 45°C.

Aerobe

An organism that utilizes oxygen and can detoxify it; includes obligate aerobes, facultative anaerobes, and microaerophiles.

Anaerobe

An organism that does not utilize oxygen; includes obligate anaerobes and aerotolerant anaerobes.

Saprobes

Free-living microorganisms that derive nutrients from dead organic matter.

Symbiosis

A close nutritional relationship between two organisms, which can be mutualistic, commensal, or parasitic.

Amensalism

A relationship where one member of the association is inhibited or destroyed by the other.

Biofilms

Complex organized layers formed when organisms attach to a substrate through an extracellular matrix.

Population growth curve

A predictable pattern of growth shown by microbial populations over time, including lag phase, exponential growth phase, stationary phase, and death phase.

Binary fission

The primary method of bacterial cell division in which a parent cell enlarges and divides into two daughter cells.

Generation time

The time required for a complete fission cycle in microbial growth, with each new cycle increasing the population by a factor of 2.