Bacteroidales

Bacteroides biacutis

The Bacteroidales make an order within the Department of Bacteroidetes. She is the only order of the class Bacteroidia.

Appearance

The Gram test is negative. There are coccoid and rod-shaped species present. Also fusiform ( spindle-shaped ) rods occur, for example, Tannerella forsythia. Spores are not formed. Some species are motile by gliding movements (moving), while others are immobile.

Occurrence

The species are found in many different habitats. So species were isolated from Marinilabilia from sea mud. Types of Blattabacterium (Family Blattabacteriaceae ) were found in termites and cockroaches and Bacteroides in the human gut.

Pathogenicity

Within the Bacteroidia some people disease-causing ( pathogenic ) species are present. Thus, Bacteroides fragilis, Bacteroides thetaiotaomicron and are opportunistic pathogens of humans.

System

The class Bacteroidia contains only an order that Bacteroidales. The systematics in detail:

• Class Bacteroidia order Bacteroidales Family Bacteroidaceae
• Family Marinilabiliaceae
• Family Porphyromonadaceae
• Family Prevotellaceae
• Family Rikenellaceae

Ecology

The individual species are mostly anaerobic. Also, facultative anaerobic, that is, able to tolerate oxygen, are present. The anaerobic genus Bacteroides is the most common bacteria in the human gut with 10 11 cells per gram.