True about mycoplasma are all except:
They arc L forms Mycoplasmas are unique organisms because they have a very small size similar to viruses but unlike viruses, they have an independent existence i.e. they can grow in cell free media. Though they can grow in cell free media but they have a limited biosynthetic ability so they need a rich growth medium containing natural animal protein (usually blood serum) and in most cases a sterol component. The sterol component is required beause mycoplasma contains sterol in their cell membrane. Mycoplasmas are also unique because they do not have a regular cell wall instead they are bound by a cell membrane consisting primarily of sterol. Because of their small size nzycoplasma usually do not produce turbidity in liquid media. A pH indicator is added to liquid media to detect growth by acid products. The absence of the cell wall gives two characteristic propey to mycoplasma:- The absence of cell wall makes them highly pleomorphic. Mycoplasmas are completely resistant to penicillin because, they lack the cell wall structure at which penicillin acts instead they are inhibited by tetracycline or erythromycin. Mycoplasma and L forms of bacteria (cell wall defective bacteria) L phase bacterias are cell wall defective bacterias that can replicate serially as non rigid cells and can produce colonies on solid media. L forms develop when many bacterias either spontaneously or induced by ceain cell wall inhibiting drugs lose pa or all of their cell wall and develop into L forms. Some L phase variants are stable; others are unstable and reve to their bacterial parental forms. It has been suggested that mycoplasmas may represent stable L forms of bacteria but genetic, antigenic and biochemical evidence are against the possibility. The characteristic of the cell wall defective forms may be similar to those of inycoplasma hut by definition, mycopla.smas do not reve to parental bacterial forms or originate from them. There is no genetic relationship between mycoplasmas and cell wall defective microbial forms or their parent bacteria.
They are L forms
Sterol enhances growth
Can grow in cell free media
When grown in liquid medium do not produces turbidity