石油基塑料的微生物降解

Microbial degradation of petroleum-based plastics

摘要:

石油基塑料种类繁多、数量巨大、应用广泛，常见的有聚乙烯 (PE)、聚丙烯 (PP)、聚苯乙烯 (PS)、聚氯乙烯 (PVC)、聚对苯二甲酸乙二醇酯 (PET)、聚氨酯 (PUR) 等。这些合成塑料因其高分子量、高疏水性及高化学键能的特点难以被微生物降解，从而在环境中长期存在和累积，“白色污染”已经成为一个全球性问题。因此安全经济的微生物降解合成塑料是人类面临的一个选择和难题。文中从微生物资源及相关酶学研究方面综述了聚苯乙烯、聚乙烯、聚丙烯、聚氨酯、聚对苯二甲酸乙二醇酯和聚氯乙烯这6种石油基塑料的生物降解的研究现状。目前关于上述6种石油基塑料的微生物降解研究依然大多停留在微生物资源的寻找中，已发现的具备相关能力的菌株种类较少，并且微生物降解效率均非常缓慢；对于其降解机理及关键基因和酶的研究比较少。文中为进一步开展塑料生物降解研究，寻找高效的塑料降解菌株资源以及进一步在遗传、分子和生化水平研究塑料生物降解机理研究，从而最终实现合成塑料的彻底降解和高值化利用提供了借鉴。

Abstract:

Synthetic plastics include polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyurethane (PUR), etc. Because of their large molecular weights, high hydrophobic characters and high chemical bond energies, they are difficult to be degraded by microbes. More and more plastic products are widespread consumed and gradually accumulated in the environment, so that the “white pollution” has become a global concern. Therefore, safe and economic microbial degradation of synthetic plastics is an option. This article reviews microbial degradation of six petroleum-based plastics, including polyethylene, polystyrene, polypropylene, polyurethane, polyethylene terephthalate and polyvinyl chloride, from the aspects of microbial strains involved and the related enzymatic studies. This paper provides clues for the further study of the microbial degradation of synthetic plastics, including the screening of a variety of plastic degrading bacteria and microflora, and the functional identification of their degradation mechanism at the genetic, molecular and biochemical levels. Hopefully, efficient resolutions for complete biodegradation of plastics together with production of high added-value products can then be materialized in the future.