Institute for Research in Bioenergy (IPBEN), University of São Paulo State (UNESP), Rio Claro, SP, 13500-230, Brazil.
Department of Materials Engineering, São Carlos School of Engineering (EESC), University of São Paulo (USP), São Carlos, 13566-590, Brazil.
Chemosphere. 2022 Jan;287(Pt 3):132290. doi: 10.1016/j.chemosphere.2021.132290. Epub 2021 Sep 21.
Developing novel renewable (and preferably biodegradable) materials has become recurrent due to the growing concerns with environmental impacts of high volumes of plastic waste produced from oil-based sources over the past decades. This study aimed at developing bioplastics from a mixture of starch and xylan in variable ratios, and the combined effect of α-cellulose and holocellulose extracted from sugarcane bagasse added to the process. The disintegration of bioplastics was evaluated in both soil and composting. The ecotoxicity analyses with Saccharomyces cerevisiae, Bacillus subtilis and seeds of Cucumis sativus were conducted after disintegration. All formulations based on 5% (w/v) of total polysaccharides were dried at 30 °C and resulted in homogeneous and non-brittle bioplastics. The composting results showed that all bioplastic formulations disintegrated in 3 days, whereas the 25/75% (xylan/starch, w/w) formulation vanished in soil within 13 days. The ecotoxicity data showed no inhibition of microbial growth after biodegradation, yielding 100% of seed germination. Despite the positive influence of the bioplastic degradation on the root and hypocotyl growth, temporary inhibition of C. sativus tissues exposed to soil washing (10 days of disintegration) was observed. The study demonstrated that xylan/starch bioplastics result in non-ecotoxic biodegradable materials.
由于过去几十年中，石油基来源产生的大量塑料废物对环境造成的影响日益引起关注，因此开发新型可再生（最好是可生物降解）材料已成为当务之急。本研究旨在开发由淀粉和木聚糖以不同比例混合而成的生物塑料，并在该过程中添加从甘蔗渣中提取的α-纤维素和全纤维素。在土壤和堆肥中评估了生物塑料的崩解情况。在崩解后，使用酿酒酵母、枯草芽孢杆菌和黄瓜种子进行了生态毒性分析。所有基于 5%（w/v）总多糖的配方均在 30°C 下干燥，得到了均匀且不易碎的生物塑料。堆肥结果表明，所有生物塑料配方在 3 天内崩解，而 25/75%（木聚糖/淀粉，w/w）配方在土壤中 13 天内消失。生态毒性数据显示，生物降解后微生物生长没有受到抑制，种子发芽率达到 100%。尽管生物塑料降解对根和下胚轴生长有积极影响，但在土壤冲洗（10 天崩解）中暴露的黄瓜组织受到了暂时抑制。研究表明，木聚糖/淀粉生物塑料是一种非生态毒性的可生物降解材料。
