Abstract

The rising production and consumption of plastics, coupled with their intrinsic robustness, has resulted in the accumulation of up to 200 million tons of plastic waste in landfills and the environment each year. Of all these synthetic polymers, polyethylene terephthalate (PET) is the most widely used in the world. As environmental microorganisms have begun evolving their own biological means to metabolize plastics, they potentially present a sustainable method to recycle PET and retain its material value for subsequent use through biodegradation. Here, we evaluate the feasibility of using multiple PET-degrading bacterial strains (Thermobifida fusca, Ideonella sakaiensis, Pseudomonas mendocina) concurrently to develop an industrial co-culture solution. The growth behavior of each strain was evaluated at temperatures ranging from 30-60 °C and in a Hipolypepton-based media. UV-treated PET pellets were then incubated in monoculture and co-culture cell suspensions for 2 days, and degradation was measured through a spectrophotometric assay. A 1:1 T. fusca/I. sakaiensis co-culture was found to achieve a higher biodegradation efficiency compared to I. sakaiensis monoculture but not compared to T. fusca monoculture, suggesting the need for further optimization of degradation conditions. Although our studies demonstrate the great potential of biodegradation as a solution for the plastic waste crisis, the direct application of microbes may not be suitable for industrial use when compared to alternative biodegradative methods.

摘要

塑料产量和消费量的增加，加上其固有的坚固性，导致每年在垃圾填埋场和环境中积累多达 2 亿吨塑料废​​物。在所有这些合成聚合物中，聚对苯二甲酸乙二醇酯 (PET) 是世界上使用最广泛的。随着环境微生物开始进化出自己的生物方法来代谢塑料，它们可能会提供一种可持续的方法来回收 PET 并通过生物降解保留其材料价值以供后续使用。在这里，我们评估了使用多种 PET 降解细菌菌株（Thermobifida fusca、Ideonella sakaiensis、Pseudomonas mendocina）的可行性) 同时开发工业共培养解决方案。在 30-60 °C 的温度范围内和基于 Hipolypepton 的培养基中评估每个菌株的生长行为。然后将经过紫外线处理的 PET 颗粒在单培养和共培养细胞悬浮液中培养 2 天，并通过分光光度法测定降解情况。A 1:1  T. fusca/I。发现Sakaiensis共培养与I. sakaiensis单一培养相比实现了更高的生物降解效率，但与T. fusca相比则没有单一栽培，表明需要进一步优化降解条件。尽管我们的研究证明了生物降解作为解决塑料废物危机的巨大潜力，但与替代生物降解方法相比，微生物的直接应用可能不适合工业用途。