Complete Biodegradation of 4-Fluorocinnamic Acid by a Consortium Comprising Arthrobacter sp. Strain G1 and Ralstonia sp. Strain H1

A consortium of the newly isolated bacterial strains Arthrobacter sp. strain G1 and Ralstonia sp. strain H1 utilized 4-fluorocinnamic acid for growth under aerobic conditions. Strain G1 converted 4-fluorocinnamic acid into 4-fluorobenzoic acid and used the two-carbon side chain for growth, with some formation of 4-fluoroacetophenone as a dead-end side product. In the presence of strain H1, complete mineralization of 4-fluorocinnamic acid and release of fluoride were obtained. Degradation of 4-fluorocinnamic acid by strain G1 occurred through a β-oxidation mechanism and started with the formation of 4-fluorocinnamoyl-coenzyme A (CoA), as indicated by the presence of 4-fluorocinnamoyl-CoA ligase. Enzymes for further transformation were detected in cell extract, i.e., 4-fluorocinnamoyl-CoA hydratase, 4-fluorophenyl-β-hydroxy propionyl-CoA dehydrogenase, and 4-fluorophenyl-β-keto propionyl-CoA thiolase. Degradation of 4-fluorobenzoic acid by strain H1 proceeded via 4-fluorocatechol, which was converted by an ortho-cleavage pathway.