Which type of bacteria thrive in environments with less oxygen?

Obligate anaerobes are bacteria that thrive in environments where oxygen is either absent or present at very low levels. These microorganisms rely on anaerobic respiration or fermentation to generate energy, meaning they have evolved various metabolic pathways that do not utilize oxygen. In fact, oxygen can be toxic to obligate anaerobes, leading to their death or impaired growth when exposed to it.

This ability to survive and grow in low-oxygen environments allows obligate anaerobes to inhabit diverse ecological niches, such as the gastrointestinal tract of humans and animals, deep-sea vents, and decaying organic material. Understanding their metabolism and growth conditions is essential in microbiology because they play crucial roles in processes like decomposition and nutrient cycling.