Accelerated Reduction and Recycling of Solid Wastes by Application of Enzymes Capable of Green Plastic Degradation

利用淀粉和PVA降解菌和降解酶对聚乙烯醇（PVA）-淀粉共混塑料Mater-bi AF 10 H进行了加速降解试验，模拟其在自然环境中的降解，最终的重量损失小于40%，并且没有膜破裂。淀粉降解细菌和-淀粉酶引起更快速和广泛的体重减轻（最大，另一方面，当施加PVA降解细菌或酶时，最大重量损失为约50%，而当施加PVA降解细菌或酶时，最大重量损失为约50%。在最佳条件下，酶的应用特别有效，并导致膜在10天内破碎成小块。这些表明PVA级分的降解对于Mater-bi的完全降解是重要的和必要的。另一方面，乙酸纤维素塑料不能通过应用脂肪酶和/或纤维素酶降解。然而，在最佳条件下，紫外光处理后，其失重率可达60%左右，这对加速绿色塑料的降解，促进固体废弃物的减量化和资源化是一个巨大的成功。

Attempts were made to accelerate the degradation of an polyvinyl alcohol (PVA)-starch blend plastic, Mater-bi AF10H, by applying starch- and PVA-degrading bacteria and enzymes.Mater-bi degradation tests by an activated sludge, simulating its degradation in natural environment, resulted in the ultimate weight loss of less than 40 % and no film breakage.Applications of a starch-degrading bacterium and a-amylase caused more rapid and extensive weight loss (max. 50 %) than the activated sludge, however the apparent film breakage was not also observed.On the other hand, when a PVA-degrading bacterium or enzyme was applied, a maximal weight loss of ca. 70 % was achieved and film breakage occurred.The enzyme application was especially effective, and led to the film fragmentation into small pieces within 10 days under an optimal condition.These suggested that the degradation of PVA fraction is important and requisite for complete degradation of Mater-bi.On the other hand, an acetate cellulose plastic could not be degraded by applying lipase and/ or cellulase enzymes.However, when it was tre-treated by UV irradiation, about 60 % of weight loss was performed at an optimal condition.As a conclusion, this is a great success for accelerating degradation of green plastics, leading also to acceleration of reduction and recycling of solid wastes.