SEQUENTIAL DEMETHOXYLATION REACTIONS DURING METHYLOTROPHIC GROWTH OF METHOXYLATED AROMATIC SUBSTRATES WITH EUBACTERIUM-LIMOSUM

The exploitation of methoxylated aromatic monomers by Eubacterium limosum was restricted to the cleavage and consumption of the methoxyl substituents: the phenolic residues were not further attacked. Growth characteristics were similar to those previously described for this organism on methanol. Degradation of aromatics containing more than one methoxyl group occurred in a sequential manner and transient accumulation of intermediates (particularly methyl-gallate) took place, though the enzymic mechanism for this phenomenon remains obscure. Degradation of 3,4,5-trimethoxybenzoate necessitated the initial attack of the para-methoxyl group before those groups in meta positions could be metabolised.