The smallest living cells are Mycoplasmas. These bacteria lack a cell wall, which makes them incredibly small. Mycoplasma pneumoniae, for instance, is a well-known human pathogen. Some Mycoplasmas are aerobes, while others are facultative anaerobes.
Mycoplasmas are fascinating because they push the limits of what we consider a living organism. Their small size and lack of a cell wall make them difficult to study, but they also offer unique opportunities to understand the essential components of life.
