A big challenge of the 21st century is to cope with the huge amounts of plastic waste on Earth. Especially the oceans are heavily polluted with plastics. To counteract this issue, biological (enzymatic) plastic decomposition is increasingly gaining attention. Recently it was shown that polyethylene terephthalate (PET) can be degraded in a saltwater-based environment using bacterial PETase produced by a marine diatom. At moderate temperatures, plastic biodegradation is slow and requires sensitive methods for detection, at least at initial stages. However, conventional methods for verifying the plastic degradation are either complex, expensive, time-consuming or they interfere with the degradation process. Here, we adapt lensless digital holographic microscopy (LDHM) as a new application for efficiently monitoring enzymatic degradation of a PET glycol copolymer (PETG). LDHM is a cost-effective, compact and sensitive optical method. We demonstrate enzymatic PETG degradation over a time course of 43 days employing numerical analysis of LDHM images.

21世纪的一大挑战是应对地球上的大量塑料废物。特别是海洋被塑料严重污染。为了解决这个问题，生物（酶）塑性分解越来越受到关注。最近显示，使用海洋硅藻产生的细菌PETase可以在盐水环境中降解聚对苯二甲酸乙二醇酯（PET）。在中等温度下，塑料的生物降解速度很慢，并且至少在初始阶段需要灵敏的检测方法。但是，用于验证塑料降解的常规方法要么复杂，昂贵，耗时，要么会干扰降解过程。这里，我们将无透镜数字全息显微镜（LDHM）用作一种新的应用程序，以有效监控PET乙二醇共聚物（PETG）的酶促降解。LDHM是一种经济高效，紧凑且灵敏的光学方法。我们展示了LDHM图像的数值分析在43天的时间过程中酶PETG降解。