Faculty of Chemistry, Biotechnology and Food Science, NMBU - Norwegian University of Life Sciences, Ås, Norway.
Department of Chemical and Biological Engineering, University of Delaware, Newark, DE, USA.
Nat Commun. 2024 Oct 1;15(1):8501. doi: 10.1038/s41467-024-52665-z.
Biocatalytic degradation of non-hydrolyzable plastics is a rapidly growing field of research, driven by the global accumulation of waste. Enzymes capable of cleaving the carbon-carbon bonds in synthetic polymers are highly sought-after as they may provide tools for environmentally friendly plastic recycling. Despite some reports of oxidative enzymes acting on non-hydrolyzable plastics, including polyethylene or poly(vinyl chloride), the notion that these materials are susceptible to efficient enzymatic degradation remains controversial, partly driven by a general lack of studies independently reproducing previous observations. Here, we attempt to replicate two recent studies reporting that deconstruction of polyethylene and poly(vinyl chloride) can be achieved using an insect hexamerin from Galleria mellonella (so-called "Ceres") or a bacterial catalase-peroxidase from Klebsiella sp., respectively. Reproducing previously described experiments, we do not observe any activity on plastics using multiple reaction conditions and multiple substrate types. Digging deeper into the discrepancies between the previous data and our observations, we show how and why the original experimental results may have been misinterpreted.
非水解塑料的生物催化降解是一个快速发展的研究领域，其驱动力是全球废物的积累。能够切断合成聚合物中碳-碳键的酶是备受追捧的，因为它们可能为环保型塑料回收提供工具。尽管有一些关于氧化酶作用于非水解塑料（包括聚乙烯或聚氯乙烯）的报道，但这些材料是否容易受到有效酶降解的观点仍然存在争议，部分原因是缺乏独立重复先前观察结果的研究。在这里，我们试图复制最近的两项研究，这两项研究报告称，使用来自家蚕（所谓的“刻瑞斯”）的昆虫六聚体或来自克雷伯氏菌的细菌过氧化氢酶-过氧化物酶，可以实现聚乙烯和聚氯乙烯的解构。在使用多种反应条件和多种底物类型的情况下，我们复制了之前描述的实验，但没有观察到任何塑料活性。深入研究先前数据与我们观察结果之间的差异，我们展示了原始实验结果可能是如何以及为何被误解的。
