Kinetics of aerob microbial degradation of aliphatic polyesters

An automated laboratory test system was developed for measuring the aerobic biodegradation kinetics of aliphatic polyesters under standardized conditions in an aqueous model system. Biodegradation kinetics was monitored by measuring microbial carbon dioxide production and oxygen consumption resulting from the degradation process. It was observed that biodegradation of P(3HB) and PCL was rate limited by the enzymatic polymer cleavage. A linear increase of the maximum degradation rate with increasing specific polymer surface area was measured. These results confirm that the enzymatic cleavage is a surface-bound process. The temperature dependency of the biodegradation rate followed the Arrhenius law within the mesophilic and thermophilic temperature range.