Abstract

Degradation of the blends of polypropylene (PP) and poly-L-lactide (PLLA) by bacterial isolates in soil microcosm and field environment was studied. Five Bacillus strains (B. cereus (P3) and P13), B. thuringenesis (P8 and P10) and B. licheniformis (P6)) isolated from composted samples were used in this study. In microcosm, polymer blends were buried in soil augmented with bacterial isolates and studied bacterial population and degradation ability. The bacterial population (cfu/g soil) increased with time where maximum growth was observed in consortium. The formation of bacterial biofilm was observed on the surface of polymers. FTIR analysis revealed breakage of carbonyl bonds in polymeric blends and thermal stability of the blends decreased as observed through TGA analysis. Field experiment was carried out by burying the blends in an open-field augmented with bacterial consortium for 6 months. Mechanical strength and thermal stability of blends decreased in bacterial treated samples than control. These results suggest that Bacillus species enhances degradation of polymeric blends and can be used in remediation technologies for waste management practices.

摘要

研究了土壤微观世界和田间环境中细菌分离物对聚丙烯（PP）和聚-L-丙交酯（PLLA）共混物的降解作用。五种芽孢杆菌菌株（蜡状芽孢杆菌（P3）和 P13）、苏云金芽孢杆菌（P8 和 P10）和地衣芽孢杆菌(P6)) 从堆肥样品中分离出来用于本研究。在微观世界中，聚合物混合物被埋在土壤中，并增加了细菌分离物，并研究了细菌种群和降解能力。细菌种群（cfu/g 土壤）随着时间的推移而增加，其中在联合体中观察到最大生长。在聚合物表面观察到细菌生物膜的形成。FTIR 分析显示聚合物共混物中的羰基键断裂，共混物的热稳定性降低，如通过 TGA 分析观察到的。通过将混合物埋在增加了细菌聚生体的露天场地中进行了 6 个月的田间实验。与对照相比，细菌处理样品的共混物的机械强度和热稳定性降低。这些结果表明，芽孢杆菌 物种增强了聚合物混合物的降解，可用于废物管理实践的修复技术。