Abstract: A process for the treatment of aqueous effluents containing at least one of the following ethers is described: ethyl tert-butyl ether (ETBE) and/or methyl tert-butyl ether (MTBE) and/or tert-amyl methyl ether (TAME) in order to reduce the concentration of these ethers. A bacterium Gordonia terrae CIP I-2194 is innoculated under aerobic conditions. In particular, a bacterium Burkholderia cepacia CIP I-2052 or a bacterium Alcaligenes sp. CIP I-2561 or a bacterium Mycobacterium sp. CIP I-2562 is added in the presence of a growth substrate and, optionally, of a cobalt salt, and the ether contained in the effluents is degraded by the bacteria thus innoculated until its mineralization. The process is useable in the ether-contaminated water treatment industry.