Microbial degradation of piperonylic acid

Several organisms were isolated for their ability to utilize piperonylate as a sole carbon source for growth and a Pseudomonas species (Ps. PP-2) was selected for a study of the degradation of this substrate. Only vanillate, isovanillate, p-hydroxybenzoate and protocatechuate, of several possible catabolities, served as growth and oxidation substrates for the organism. Detailed analysis of the culture fluid from piperonylate-grown cells revealed the presence of vanillate and protocatechuate but isovanillate, p-hydroxybenzoate and m-hydroxybenzoate were not detected. The evidence presented suggests that piperonylate is metabolized first to vanillate by methylenedioxy ring cleavage and next to protocatechuate by direct dimethylation of vanillate.