BIOL 2460 Chapter 4

Prokaryotes

Microorganisms that lack a nucleus, including bacteria and archaea.

Ubiquitous

Present or existing everywhere; referring to prokaryotes found in diverse habitats.

Symbiotic environment

A relationship between different entities where both benefit, commonly seen in prokaryotes living together.

Microbiome

The community of microorganisms living in a specific environment, particularly within a host organism.

Bergey’s Manual of Systematic Bacteriology

A standard reference for the classification and identification of bacteria.

Gram-negative bacteria

Bacteria that do not retain the crystal violet stain used in the Gram staining procedure, appearing pink.

Proteobacteria

A major phylum of gram-negative bacteria that includes a wide variety of pathogens and environmental bacteria.

Alphaproteobacteria

A class within Proteobacteria that includes many important pathogens and nitrogen-fixing bacteria.

Gammaproteobacteria

The most diverse class of Proteobacteria, including many known pathogenic bacteria.

Epsilonproteobacteria

The smallest class of Proteobacteria, consisting of microaerophilic bacteria.

Spirochetes

A group of bacteria characterized by their unique spiral or corkscrew shape.

Cyanobacteria

Photosynthetic bacteria that can produce oxygen as a byproduct, also known as blue-green algae.

Actinobacteria

A group of gram-positive bacteria notable for their high G+C content in DNA and filamentous growth.

Firmicutes

A phylum of bacteria characterized by a low G+C content and includes many endospore-formers.

Bacillus

A genus of gram-positive bacteria that are rod-shaped and often form endospores.

Mycoplasma

A genus of bacteria that lack a cell wall and are known for their pleomorphic shapes.

Methanogenesis

A metabolic process by which certain organisms produce methane, typically found in anaerobic conditions.

Archaea

A domain of single-celled microorganisms distinct from bacteria, often living in extreme environments.

Thermophiles

Organisms that thrive at relatively high temperatures, often found in hot springs.

Endospore

A dormant, tough, and non-reproductive structure produced by some bacteria for survival under unfavorable conditions.