摘要
      随着全球对塑料污染的担忧加剧，人们正在努力寻找传统塑料的环保替代品。生物塑料作为一种可能的解决方案正在被广泛研究和开发。本研究比较了聚乳酸（PLA）和聚羟基丁酸（PHB）两种生物塑料在厌氧消化（AD）过程中对抗生素抗性基因（ARGs）和可移动遗传元件（MGE）增殖的影响。两种生物塑料（250-500个颗粒）都可以在79天内降解到一定程度，这表明甲烷产量高于没有生物塑料颗粒的对照。与用PHB和PLA颗粒修正的其他反应器相比，PHB 500反应器显示出最高的甲烷产量和最高的生物降解效率（91%）。在PLA 500中也观察到最高的ARG和MGE丰度，在PLA 250中观察到最低的ARG丰度。相反，PHB反应器显示出比对照相对较低的ARG丰度。相关性分析表明，大多数ARG与PLA呈正相关，与PHB呈负相关（tetA、tetB和tetX除外）。此外，通过相关性分析揭示了PLA和PHB反应器中MGE和ARGs之间的相关性。这些结果表明，AD对不同类型/水平的生物塑料的反应不同，这最终会影响ARG的增殖行为。因此，生物塑料也可能构成传播抗生素耐药性的潜在风险。这些发现可以作为制定生物塑料环境标准和制定监测和控制措施的基础，以防止对公众健康的潜在负面影响。
Abstract
As the global concern over plastic pollution grows, efforts are underway to find environmentally friendly alternatives to traditional plastics. Bioplastics are being extensively researched and developed as a possible solution. This study compared the impact of two bioplastics, polylactic acid (PLA) and polyhydroxy butyrate (PHB), on the proliferation of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) during anaerobic digestion (AD). Both bioplastics (250-500 particles) could be degraded to a certain extent over 79 days, as indicated by higher methane production than the control without bioplastic particles. The PHB 500 reactor showed the highest methane yield along with the highest biodegradation efficiency (91%) than other reactors amended with PHB and PLA particles. The highest ARG and MGE abundances were also observed in PLA 500, and the lowest ARG abundance was in PLA 250. Conversely, PHB reactors showed a relatively lower ARG abundance than the control. The correlation analysis suggested that most ARGs were positively correlated with PLA and negatively correlated with PHB (except for tetA, tetB, and tetX). Moreover, a correlation between MGEs and ARGs in PLA and PHB reactors was revealed by correlation analysis. These results show that AD responds differently to the different types/levels of bioplastics, which can ultimately influence the behavior of ARG proliferation. Thus, bioplastics may also pose a potential risk for spreading antibiotic resistance. These findings can be used as a basis for setting environmental standards for bioplastics and creating monitoring and control measures to prevent potential negative impacts on public health.

https://www.sciencedirect.com/science/article/pii/S0160412023002118