EFFECTS OF MOLECULAR-STRUCTURE ON ENZYMATIC DEGRADATION OF POLYESTERS

Enzymatic degradation of eleven types of microbial and synthetic polyesters; poly[(R)-3-hydroxybutyrate] (1), poly[(S)-3-hydroxybutyrate] (2), atactic poly[(R,S)-3-hydroxybutyrate] (3), poly[(R)-3-hydroxyvalerate] (4), poly(3-hydroxypropionate) (5), poly[(R)-2-hydroxypropionate] (6), poly(4-hydroxybutyrate) (7), poly(5-hydroxyvalerate) (8), poly (6-hydroxyhexanoate) (9), poly(ethylene adipate) (10) and poly(1,4-butylene adipate) (11) was investigated at 37-degrees-C and pH 7.4 in the aqueous solution of extracellular P(3 HB) depolymerase from Alcaligenes faecalis. The rate of enzymatic degradation decreased in the following order; (1) = (5) > (10) > (3) > (4) = (7) > (2) = (6) = (8) = (9) = (11) = 0. The relation between the molecular structure and the rate of enzymatic degradation of polyesters has been discussed.