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Degradation of methoxylated aromatic acids by Pseudomonas putida
Author(s) -
Turner J.E.,
Allison N.
Publication year - 1995
Publication title -
journal of applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0021-8847
DOI - 10.1111/j.1365-2672.1995.tb02832.x
Subject(s) - phenylacetic acid , pseudomonas putida , dioxygenase , cleavage (geology) , bacteria , biochemistry , enzyme , substrate (aquarium) , chemistry , demethylase , energy source , catechol , pseudomonas , stereochemistry , biology , organic chemistry , dna , coal , paleontology , ecology , genetics , fracture (geology) , histone
J.E. TURNER AND N. ALLISON. 1995. A newly‐isolated strain of Pseudomonas putida (HVA‐1) utilized homovanillic acid as sole carbon and energy source. Homovanillate‐grown bacteria oxidized homovanillate and homoprotocatechuate but monohydroxylated and other methoxylated phenylacetic acids were oxidized poorly; methoxy‐substituted benzoates were not oxidized. Extracts of homovanillate‐grown cells contained homoprotocatechuate 2,3‐dioxygenase but the primary homovanillate‐degrading enzyme could not be detected. No other methoxylated phenylacetic acid supported growth of the organism but vanillate was utilized as a carbon and energy source. When homovanillate‐grown cells were used to inoculate media containing vanillate a 26 h lag period occurred before growth commenced. Vanillate‐grown bacteria oxidized vanillate and protocatechuate but no significant oxygen uptake was obtained with homovanillate and other phenylacetic acid derivatives. Analysis of pathway intermediates revealed that homovanillate‐grown bacteria produced homoprotocatechuate, formaldehyde and the ring‐cleavage product 5‐carboxymethyl 2‐hydroxymuconic semialdehyde (CHMS) when incubated with homovanillate but monohydroxylated or monomethoxylated phenylacetic acids were not detected. These results suggest that homovanillate is degraded directly to the ring‐cleavage substrate homoprotocatechuate by an unstable but highly specific demethylase and then undergoes extradiol cleavage to CHMS. It would also appear that the uptake/degradatory pathways for homovanillate and vanillate in this organism are entirely separate and independently controlled. If stabilization of the homovanillate demethylase can be achieved, there is potential for exploiting the substrate specificity of this enzyme in both medical diagnosis and in the paper industry.