Degradation of Acetylsalicylic Acid by a Strain of Acinetobacter Iwoffii

SUMMARY: A strain of Acinetobacter Iwoffii , isolated from a stored sample of distilled water, hydrolysed acetylsalicylic acid to salicylic and acetic acids. It grew in mineral salts medium with either of these compounds as C source and NH₄⁺ as N source. Experiments with whole cells and cell free extracts and the isolation of intermediates showed that acetylsalicylic acid was metabolized through salicylic acid, catechol, cis-cis -muconic acid, (+)-muconolactone and β-oxoadipic acid. The salicylate hydroxylase required NADH or NADPH as cofactor and 1 mole of O₂ was taken up and 1 mole of CO₂ evolved for each mole of salicylate oxidized. Catalytic quantities of flavine adenine dinucleotide (FAD) but not flavine mononucleotide (FMN) activated the enzyme. The cis-cis -muconate lactonizing enzyme was activated by Mn²⁺ and inhibited by EDTA.