Abstract: Disclosed is a method for monitoring the degradation of methyl tert-butyl ether in a contaminated media which contains methyl tert-butyl ether and/or which is treated under conditions which cause the degradation of methyl tert-butyl ether into 2-hydroxy isobutyric acid comprising: (A) evaluating the treated contaminated media to determine the absence or presence therein of 2-hydroxy isobutyric acid; (B) based on such evaluation, determining whether the conditions should be modified; and (C) modifying such conditions as may be necessary. Disclosed also is a method for degrading an ether comprising contacting the ether with a microorganism that is effective in oxidizing propane or isopropanol and 2-hydroxy-isobutyric acid.