Premium
O‐Demethylation, dehydroxylation, ring‐reduction and cleavage of aromatic substrates by Enterobacteriaceae under anaerobic conditions
Author(s) -
GrbicGalic D.
Publication year - 1986
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.1365-2672.1986.tb01721.x
Subject(s) - chemistry , phenols , organic chemistry , demethylation , aromatic amino acids , biotransformation , anaerobic bacteria , bacteria , biochemistry , biology , gene expression , genetics , dna methylation , gene , enzyme
Four fermentative facultative anaerobes, members of the genera Enterobacter and Escherichia , were tested for their ability to transform an aromatic lignin derivative, 3‐methoxy‐4‐hydroxy‐cinnamic acid (ferulic acid), under anaerobic (fermentative) conditions. The pure cultures studied were shown to O‐demethylate, dehydroxylate, reduce the double bond in the side‐chain, decarboxylate the aromatic ring to the stage of benzoate and to reduce the ring to an alicyclic acid. Aromatic hydrocarbons (toluene, ethylbenzene and propylbenzene), as well as phenols (phenol, o‐cresol, p‐cresol, 2‐ethylphenol and 3‐hydroxy‐4‐ethylphenol) were also produced. In addition, during 3 months incubation, the cleavage of the aromatic ring occurred, whereby a small fraction of the substrate was converted to straight‐chain and branched (methylated, ethylated) five‐ to eight‐carbon aliphatic acids. The results indicate that pure cultures of fermentative facultative anaerobes might be capable of degrading substituted aromatic acids to aliphatic products under strictly anaerobic (fermentative) conditions. These abilities, which have so far been found only in denitrifying pseudomonads among facultative anaerobes, might be common in Enterobacteriaceae. It is conceivable that these bacteria are important as degraders of aromatic compounds in anaerobic ecosystems.