Alphaproteobacteria

Definition

Alphaproteobacteria are a class of bacteria within the phylum Proteobacteria, known for their diverse metabolic capabilities and ecological roles. They include many agriculturally and medically important species.

5 Must Know Facts For Your Next Test

1. Alphaproteobacteria include nitrogen-fixing bacteria such as Rhizobium, which form symbiotic relationships with legumes.
2. Members of this class can be found in aquatic environments, soil, and as intracellular pathogens.
3. Some species, like Rickettsia, are known to cause diseases in humans and animals.
4. They exhibit a wide range of metabolic diversity, including photoautotrophy, chemoautotrophy, and heterotrophy.
5. Alphaproteobacteria are thought to be the ancestors of mitochondria due to their close genetic relationship.

Review Questions

Related terms

Proteobacteria:

A major phylum of Gram-negative bacteria that includes a wide variety of pathogens.

Rhizobium:

A genus of Alphaproteobacteria that forms symbiotic relationships with leguminous plants for nitrogen fixation.

Rickettsia:

A genus of Alphaproteobacteria known for causing diseases such as Rocky Mountain spotted fever.