Su Yu-Ao, Liu Hong-Bo, Mao Qiu-Yan, Zhang Hui-Min, Zhang Yan, Liu He
School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China.
Jiangsu Key Laboratory of Anaerobic Biotechnology, Wuxi 214122, China.
Huan Jing Ke Xue. 2020 Jun 8;41(6):2812-2821. doi: 10.13227/j.hjkx.201911092.
To investigate the potential interference of dead bacteria DNA on the analysis of antibiotic resistance genes (ARGs) and microbial communities in anaerobic digestion sludge, three different types of anaerobic digestion sludge were treated with propidium monoazide (PMA) in this study, and the results of subsequent ARGs and microbial community analysis with the interference of dead cell DNA blocked by PMA was compared to that without PMA treatment. It was found that after PMA treatment, the absolute abundance of the ARGs in the anaerobic digestion sludge from self-anaerobic digestion system of excess sludge and from high solid sludge anaerobic digestion system decreased by 41%-86%, and 74%-98%, respectively. ARGs abundance in the sludge from the anaerobic digestion system with sludge hydrolyzate as a substrate and anaerobic granular sludge as inoculum after 15 days of digestion considerably decreased with PMA treatment. However, its ARGs abundance still declined by up to 34%. PMA treatment influenced the analysis of microbial community of the three types of anaerobic digestion sludge to different degrees, in which the influence was the highest on the community structure analysis of the sludge from high solid anaerobic digestion system. The results of the correlation analysis between the ARGs abundance and the microbial community composition were completely different in the case with PMA treatment and without PMA treatment. This study proved the potential interference of dead cell DNA on the analysis of ARGs and microbial community in anaerobic digestion sludge. PMA pretreatment could achieve a more accurate analysis of the microbial community and ARGs characteristics in anaerobic digestion sludge.
为研究死菌DNA对厌氧消化污泥中抗生素抗性基因（ARGs）及微生物群落分析的潜在干扰，本研究采用单叠氮化丙锭（PMA）处理三种不同类型的厌氧消化污泥，并将PMA阻断死细胞DNA干扰后ARGs和微生物群落分析结果与未进行PMA处理的结果进行比较。结果发现，经PMA处理后，剩余污泥自厌氧消化系统和高固体污泥厌氧消化系统的厌氧消化污泥中ARGs的绝对丰度分别下降了41% - 86%和74% - 98%。以污泥水解产物为底物、厌氧颗粒污泥为接种物的厌氧消化系统污泥在消化15天后，经PMA处理后ARGs丰度显著下降，但其ARGs丰度仍下降高达34%。PMA处理对三种类型厌氧消化污泥的微生物群落分析有不同程度的影响，其中对高固体厌氧消化系统污泥的群落结构分析影响最大。PMA处理和未处理情况下ARGs丰度与微生物群落组成的相关性分析结果完全不同。本研究证明了死细胞DNA对厌氧消化污泥中ARGs和微生物群落分析存在潜在干扰。PMA预处理能够更准确地分析厌氧消化污泥中的微生物群落和ARGs特征。
