摘要
      生物浸出被认为是一种很有前途的修复沉积物重金属污染的技术。在生物浸出过程中，来自生物浸出金属的压力更有可能导致抗生素抗性基因（ARGs）的传播。本研究比较了两种典型的重金属生物浸出处理中ARGs丰度的变化。结果表明，两种处理都能成功地生物浸出重金属，功能菌对Cu的去除率较高。生物浸出后，大多数ARG的绝对丰度下降了一个对数单位，特别是tetR（p=0.02）和tetX（p=0.04），intI1从106拷贝/g下降到104拷贝/g。就相对丰度而言，无药剂处理中的ARGs从3.90×10−4增加到1.67×10−3拷贝/16S rRNA基因拷贝（p=0.01），而有药剂处理中，ARGs达到6.65×10−2拷贝/16S r RNA基因拷贝，intI1相对丰度维持在10−3副本/16S rNA基因拷贝。与外排泵机制和核糖体保护机制相关的ARGs的相对丰度增加最多。共生网络表明，生物浸出的Cu是决定ARGs分布的环境因素，厚壁菌门可能是ARGs的潜在宿主。与用本土细菌进行的生物浸出相比，添加功能性细菌制剂会降低微生物α多样性，增加生物浸出的Cu量，从而导致ARGs的相对丰度更高。使用这两种生物浸出处理可以有效地去除沉积物中的重金属污染，然而，应考虑这些程序造成的ARGs传播的风险，特别是使用功能性细菌制剂的处理。未来，应该开发一种经济高效的绿色技术，同时降低ARGs的绝对丰度和相对丰度。
Abstract
Bioleaching is considered a promising technology for remediating heavy metals pollution in sediments. During bioleaching, the pressure from the metals bioleached is more likely to cause the spread of antibiotic resistance genes (ARGs). The changes in abundance of ARGs in two typical heavy metal bioleaching treatments using indigenous bacteria or functional bacteria agent were compared in this study. Results showed that both treatments successfully bioleached heavy metals, with a higher removal ratio of Cu with functional bacteria agent. The absolute abundances of most ARGs decreased by one log unit after bioleaching, particularly tetR (p = 0.02) and tetX (p = 0.04), and intI1 decreased from 106 to 104 copies/g. As for the relative abundance, ARGs in the non-agent treatment increased from 3.90 × 10−4 to 1.67 × 10−3 copies/16S rRNA gene copies (p = 0.01), and in the treatment with agent, it reached 6.65 × 10−2 copies/16S rRNA gene copies, and intI1 relative abundance was maintained at 10−3 copies/16S rRNA gene copies. The relative abundance of ARGs associated with efflux pump mechanism and ribosomal protection mechanism increased the most. The co-occurrence network indicated that Cu bioleached was the environmental factor determining the distribution of ARGs, Firmicutes might be the potential hosts of ARGs. Compared to bioleaching with indigenous bacteria, the addition of functional bacteria agent engendered a decrease in microbial alpha diversity and an increase in the amount of Cu bioleached, resulting in a higher relative abundance of ARGs. Heavy metal pollution can be effectively removed from sediments using the two bioleaching treatments, however, the risk of ARGs propagation posed by those procedures should be considered, especially the treatment with functional bacteria agents. In the future, an economical and efficient green technology that simultaneously reduces both the absolute abundance and relative abundance of ARGs should be developed.

https://www.sciencedirect.com/science/article/abs/pii/S0048969721078293