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

通过应用淀粉和PVA降解菌和酶来加速聚乙烯醇(PVA)-淀粉共混塑料Mater-bi AF10H的降解。模拟其在自然环境中的降解，活性污泥对Mater-bi AF10H的Mater-bi降解试验结果表明，最终失重率不到40%，并且没有破膜。使用淀粉降解菌和a-淀粉酶可以使失重更快、更广泛(max.当使用PVA降解菌或酶时，膜的最大失重率可达70%左右，并且发生了膜的断裂。酶的应用尤其有效，在最佳条件下，在10天内使膜破碎成小片。这表明PVA组分的降解是材料完全降解的重要和必要条件。另一方面，使用脂肪酶和/或纤维素酶不能降解醋酸酯纤维素塑料。然而，当用紫外线照射处理时，在最佳条件下，约有60%的失重率。因此，这是加速绿色塑料降解的巨大成功，也加速了固体废物的减少和回收。

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.