Bacteroidaceae

Bacteroides fragilis in the Gram stain

Bacteroidaceae which are a family of bacteria. A special feature is the production of sphingolipids. The type genus Bacteroides is the most abundant group of bacteria in the human gut.

Appearance

It is just chopsticks. The Gram test is negative. Spores are not formed. They are anaerobically ( growth occurs only in the absence of oxygen). Most species are not motile, exceptions are eg Bacteroides xylanolyticus and types of Acetomicrobium. As a special feature among the bacteria produce several types of sphingolipids, special membrane lipids, which are typical for metazoan and actually are produced by only a few bacteria, eg those covered by the Proteobacteria Sphingomonadaceae and of the Sphingobacteriaceae the Bacteroidetes.

Metabolism

The metabolic pathway is the fermentation. You use inter alia various sugars and proteins for fermentation. End products are, inter alia, Acetate and hydrogen ( H2). The acetate formation is noted for some species, as part of their name. Products of Bacteroides are among others Succinic acid, and acetate. The genus Anaerorhabdus produces acetate and lactate.

Occurrence

The genus Bacteroides is 1011 copies per gram of stool, the dominant group of bacteria in the human digestive tract. It also occurs in the female genital tract. Other representatives, such Acetomicrobium, are found in sewage sludge.

System

The first asked about the Bacteroidaceae genus Anaerophaga is now conducted under the Marinilabiliaceae. The also asked here first genus Mega Mona is now one of the family Veillonellaceae the Firmicutes. The following classes will be provided to the family:

• Acetofilamentum Dietrich et al. 1989
• Acetomicrobium Soutschek et al. 1985
• Acetothermus Dietrich et al. 1988
• Anaerorhabdus Shah & Collins 1986
• Bacteroides Castellani & Chalmers 1919