Organic osmolytes in methanogenic archaebacteria.

Methanogenic archaebacteria have developed unique ways of dealing with osmotic stress. While several of them have transport systems capable of internalizing betaine, an osmolyte in many eubacteria, in general they have developed de novo synthesis of a novel series of beta-amino acids as compatible solutes. 13C-NMR spectroscopy has been the key tool in elucidating both the identity of these organic osmolytes and in investigating their dynamics.