Department of Biology, University of Waterloo, Waterloo, Ontario, Canada.
Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
Appl Environ Microbiol. 2021 Mar 11;87(7). doi: 10.1128/AEM.02914-20.
Wastewater management in the Canadian Arctic is challenging due to climate extremes, small population sizes, and lack of conventional infrastructure for wastewater treatment. Although many northern communities use waste stabilization ponds (WSPs) as their primary form of wastewater treatment, few studies have explored WSP microbial communities and assessed effluent impacts on receiving waters from a microbiological perspective. Here, we used 16S rRNA gene and metagenome sequencing to characterize WSP and receiving water microbial communities for two time points bracketing the spring WSP thaw in Baker Lake (Nunavut) and compared these results to other Nunavut WSPs in Cambridge Bay and Kugluktuk. Most amplicon sequence variants (ASVs) recovered from these WSP samples belonged to the phylum , with considerable variation between the three locations and only six ASVs shared among the WSPs at >0.2% relative abundance. Wastewater indicator ASVs for the Baker Lake WSP were identified, and few indicator ASVs were detected in samples originating from other upstream or downstream sites. The metagenomic data revealed a strong enrichment of antibiotic resistance genes for WSP samples relative to downstream and reference samples, especially for genes associated with macrolide resistance. Together, our results provide a baseline characterization for WSP microbial communities, demonstrate how indicator ASVs can be used to monitor attenuation and dilution of effluent microorganisms, and reveal that WSPs can serve as hot spots for antibiotic resistance genes. Given that the microbial communities of Arctic waste stabilization ponds (WSPs) are poorly studied to date, our characterization of multiple WSP systems and time points provides important baseline data that will assist with ongoing monitoring of effluent impacts on downstream aquatic ecosystems in the Arctic. This research also identifies indicator amplicon sequence variants (ASVs) of WSPs that will be helpful for future monitoring for WSP effluent attenuation and demonstrates that WSP microbial communities are enriched in antibiotic resistance genes. Given operational and infrastructure changes anticipated for wastewater treatment systems in the Arctic, baseline data such as these are essential for further development of safe and effective wastewater treatment systems.
加拿大北极地区的废水管理面临挑战，原因包括气候极端、人口规模小以及缺乏用于废水处理的常规基础设施。尽管许多北方社区将污水稳定塘 (WSP) 用作其主要的废水处理形式，但很少有研究从微生物角度探讨 WSP 微生物群落，并评估废水对受纳水体的影响。在这里，我们使用 16S rRNA 基因和宏基因组测序来描述污水稳定塘和接收水的微生物群落，时间点分别在贝克湖 (努纳武特地区) 春季污水稳定塘解冻前后，并将这些结果与剑桥湾和库鲁阿克图克的其他努纳武特污水稳定塘进行了比较。从这些污水稳定塘样本中回收的大多数扩增子序列变体 (ASV) 属于 ，在这三个地点之间存在很大差异，只有六个 ASV 在 >0.2%相对丰度时在所有污水稳定塘中共享。确定了贝克湖污水稳定塘的废水指示 ASV，并且在源自其他上游或下游地点的样本中很少检测到指示 ASV。宏基因组数据显示，与下游和参考样本相比，污水稳定塘样本中抗生素抗性基因的富集程度很强，尤其是与大环内酯类抗性相关的基因。总的来说，我们的研究结果为污水稳定塘微生物群落提供了基线特征，表明指示 ASV 可用于监测废水微生物的衰减和稀释，并揭示污水稳定塘可能成为抗生素抗性基因的热点。鉴于迄今为止对北极地区污水稳定塘 (WSP) 的微生物群落研究甚少，我们对多个 WSP 系统和时间点的特征描述提供了重要的基线数据，这将有助于对北极地区废水对下游水生生态系统的影响进行持续监测。这项研究还确定了污水稳定塘的指示扩增子序列变体 (ASV)，这将有助于未来监测污水稳定塘废水的衰减，并表明污水稳定塘微生物群落富含抗生素抗性基因。鉴于北极地区的废水处理系统预计会发生运营和基础设施变化，因此，此类基线数据对于进一步开发安全有效的废水处理系统至关重要。
