Use of phenylalanine and phenylacetate as a carbon source. 4-fumarylacetoacetate + H2O = acetoacetate + fumarate + H(+) Amino-acid degradation; L-phenylalanine degradation; acetoacetate and fumarate from L-phenylalanine: step 6/6. By phenylacetate (PhoAc), 2OH-PhoAc, 3OH-PhoAc, 4OH-PhoAc, phenylalanine, and tyrosine. Not induced by acetate or glutamate. Expression is partially repressed by glucose. Disruption of the fahA gene results in phenylalanine toxicity, secretion of succinylacetone and the absence of growth. This is analogous to the genetic disease, type I hereditary tyrosinemia in humans. Belongs to the FAH family.