Biodegradability of aromatic building blocks for poly(ethylene terephthalate) copolyesters

A biodegradability study of several aromatic building blocks used for the preparation of poly(ethylene terephthalate) copolymers of technical interest has been carried out. They include the dimethyl esters of terephthalic, 5-nitroisophthalic, and nitroterephthalic acid, as well as the 2-hydroxyethyl esters of the first two mentioned acids. Biodegradability was first evaluated on solid agar for a number of culture collection strains. Only 7 out of the 24 assayed strains showed degrading activity on some substrates. The degrading microorganisms were then isolated from environmental samples using an enrichment culture technique. Most of the environmental isolates showing degrading capability belonged to the genus Pseudomonas or Bacillus. Biodegradation with commercial lipases, esterases and proteases showed that most of the 16 tested enzymes degraded some of the substrates.