Metabolism of aromatic compounds by an alternaria species

Abstract

Washed mycelial felts of an Alternaria sp. isolated from soil, when grown on a malt extract medium, rapidly metabolized various cinnamic and benzoic acids. The intermediates in the degradation of trans-cinnamic, m-coumaric, p-coumaric, ferulic and sinapic acids have been identified. In vivo studies with ¹⁴C-labelled cinnamic acid, p-coumaric acid and benzoic acid have shown that these compounds are converted to p-hydroxybenzoic acid and protocatechuic acid. When the organism was fed with cinnamic acid-2-¹⁴C, a part of the radioactivity after 6 hr was trapped in glutamic and aspartic acids. These results strongly suggest that Alternaria shortens the cinnamic acid side-chain by β-oxidation. The organism did not have any detectable levels of phenylalanine and tryosine ammonia-lyase activities