Measurement and acceleration of biodegradation in soil

The quantitative and rapid method for measuring the biodegradation of polymer materials in soil was developed. In this study, cellophane film was used as a model biodegradable polymer and the biodegradation was assayed by measuring the amount of glucose which was produced by a hydrolysis reaction using HCl after collecting the film from soil. Cellophane film was degraded 41.2% in 4 months during winter while it was degraded 76.5% in 2 months during summer. It means that biodegradation in soil is affected by environmental conditions. The biodegradation was also measured in an incubator (30°C, humidity 50-55%) to exclude the environmental variations. Cellophane film was degraded 94% in that condition in 40 days. The biodegradation showed the first order kinetics and the rate constant was 0.067 (1/day). Acceleration of the biodegradation in soil was also studied. We added cultured soil microorganisms or nutrients such as N, P, and S into the soil. While the addition of microorganisms showed the temporary increase of rate constant, the addition of nutrients not only showed the increase of rate constant from 0.096 (1/day) to 0.21 (1/day) but also maintained the effect continuously.