Kloostrid

Kloostrid, or Clostridia, are a class of bacteria within the phylum Firmicutes. They are predominantly Gram-positive, rod-shaped, and form endospores that enable survival in harsh environments. Most kloostrider are obligate anaerobes, meaning they thrive in the absence of oxygen, though some species can tolerate low levels of oxygen for periods of time.

Ecology and metabolism: Kloostrider are widespread in soil, sediments, and the gastrointestinal tracts of humans and animals. They are primarily fermentative organisms, producing a variety of acids, solvents, gases, and toxins. Their metabolic activities play important roles in natural decomposition, nutrient cycling, and, in some cases, disease.

Notable members and clinical relevance: Several kloostrid species are medically important. Clostridium botulinum produces botulinum toxin causing botulism; Clostridium tetani causes tetanus; Clostridium perfringens is associated with gas gangrene and food poisoning; and Clostridioides difficile is a major cause of antibiotic-associated diarrhea and colitis. In addition to pathogens, non-toxigenic kloostrider contribute to soil health and gut ecology.

Industrial and environmental roles: Some kloostrider are used in biotechnology and industrial fermentation, such as solvent production by species like Clostridium acetobutylicum (historically used for acetone–butanol–ethanol fermentation). Others aid in biodegradation and conversion of plant biomass in anaerobic environments.

Taxonomy and classification: The group includes numerous species historically classified under the genus Clostridium, which is now known to be polyphyletic. Many species have been reclassified into new genera (for example, Clostridioides, Ruminiclostridium). Despite taxonomic revisions, the term kloostrid remains a useful reference for this broad, anaerobic, spore-forming lineage.