BIOL 2460 Chapter 4

Prokaryotic

Single-celled organisms that lack a nucleus, including Bacteria and Archaea.

Microbiome

The community of microorganisms living in a specific environment, such as the gut.

Proteobacteria

A major phylum of Gram-negative bacteria, diverse in morphology and metabolism.

Gram-positive Bacteria

Bacteria that retain the crystal violet stain used in the Gram staining procedure and appear purple.

Endospore

A resistant structure formed by some bacteria to survive extreme conditions.

Symbiotic relationship

A close, long-term interaction between two different biological species.

Methanogenesis

The production of methane by microbes, typically in anaerobic conditions.

Eutrophs

Organisms that require many nutrients for growth, often found in nutrient-rich environments.

Obligate anaerobes

Organisms that cannot survive in the presence of oxygen.

Biofilm

A complex aggregation of microbes that adhere to surfaces.

Causative agent

A pathogen that is responsible for causing a disease.

Anaerobic respiration

A form of respiration that occurs in the absence of oxygen.

Lactobacillus

A genus of bacteria that plays an important role in the fermentation of dairy products.

Microaerophilic

Organisms that require oxygen but at lower levels than is present in the atmosphere.

Obligate intracellular bacteria

Bacteria that can only grow within the cells of a host organism.

Bergey's Manual of Systematic Bacteriology

A standard reference for bacterial identification and classification.

Nitrogen fixation

The process of converting atmospheric nitrogen into a form usable by living organisms.

Filamentous bacteria

Bacteria that form long, thread-like structures.

Pleomorphic

Describes bacteria that can change shape or size depending on the environmental conditions.

Halophiles

Microorganisms that thrive in high salt concentrations.

Aquificae

A phylum of bacteria that includes hyperthermophilic organisms found in hot springs.