摘要

      全球每年产生约13亿吨食物垃圾（FW）。FW的很大一部分沉积在垃圾填埋场，从而造成环境污染和温室气体排放。在工业规模的堆肥过程中，越来越多的FW被更可持续地循环利用到肥料中，但对FW中存在的抗生素抗性基因（ARGs）以及它们的丰度如何受到堆肥的影响却知之甚少。为了研究这一点，我们量化了堆肥开始、期间和结束时ARGs、移动遗传元素（mge）和细菌群落的多样性和丰度。每个样本中都检测到27个ARGs和5个MGEs，表明堆肥FW仍然是ARGs和MGEs的贮存库。在堆肥过程中，细菌群落的丰富度、组成和多样性都发生了显著变化，ARG和MGE的总丰富度都有所增加。根据Procrustes分析，ARGs的变化与细菌群落组成的变化有关（P<0.01）。最重要的是，尽管高温堆肥降低了最初的ARG相关细菌类群的丰富度和多样性，但其他相关细菌类群中的ARG丰富度仍然保持不变。这可能是由水平基因转移和理化堆肥特性驱动的，这一特性在ARGs、MGEs、pH、NO3-和水分之间呈明显的正相关。综上所述，我们的研究结果表明，传统的堆肥方法不能有效地去除FW中的ARGs和MGEs。因此，需要更有效的堆肥策略，以尽量减少从堆肥的FW释放到农业环境中的ARG。

       About 1.3 billion tons of food waste (FW) is annually produced at a global scale. A major fraction of FW is deposited into landfills thereby contributing to environmental pollution and emission of greenhouse gasses. While increasing amounts of FW are recycled more sustainably into fertilizers in industrial-scale composting, very little is known about the antibiotic resistance genes (ARGs) present in FW and how their abundance is affected by composting. To study this, we quantified the diversity and abundance of ARGs, mobile genetic elements (MGEs) and bacterial communities in the beginning, during and at the end of the FW composting. All targeted 27 ARGs and 5 MGEs were detected in every sample suggesting that composted FW remains a reservoir of ARGs and MGEs. While the composting drastically changed the abundance, composition and diversity of bacterial communities, an increase in total ARG and MGE abundances was observed. Changes in ARGs were linked with shifts in the composition of bacterial communities as revealed by a Procrustes analysis (P < 0.01). Crucially, even though the high composting temperatures reduced the abundance and diversity of initially ARG-associated bacterial taxa, ARG abundances were maintained in other associated bacterial taxa. This was likely driven by horizontal gene transfer and physicochemical composting properties as revealed by a clear positive correlation between ARGs, MGEs, pH, NO₃^- and moisture. Together our findings suggest that traditional composting is not efficient at removing ARGs and MGEs from FW. More effective composting strategies are thus needed to minimize ARG release from composted FW into agricultural environments.

       https://www.sciencedirect.com/science/article/pii/S004896971835246X?via%3Dihub