School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China.
Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou 730070, China.
Int J Environ Res Public Health. 2021 Sep 15;18(18):9713. doi: 10.3390/ijerph18189713.
DNA sequencing of active cells involved in vermicomposting can clarify the roles of earthworms in regulating functional microorganisms. This study aimed to investigate the effect of earthworms on functional microbial communities in sludge by comparing biodegradation treatments with and without earthworms. PCR and high throughput sequencing based on pretreatment of propidium monoazide (PMA) were used to detect the changes in active bacterial 16S rDNA and eukaryotic 18S rDNA during vermicomposting. The results showed that the nitrate in sludge vermicomposting and control were significantly different from day 10, with a more stable product at day 30 of vermicomposting. Compared with the control, the Shannon indexes of active bacteria and eukaryotes decreased by 1.9% and 31.1%, respectively, in sludge vermicompost. Moreover, Proteobacteria (36.2%), Actinobacteria (25.6%), and eukaryotic Cryptomycota (80.3%) were activated in the sludge vermicompost. In contrast, the control had Proteobacteria (44.8%), Bacteroidetes (14.2%), Cryptomycota (50.00%), and Arthropoda (36.59%). Network analysis showed that environmental factors had different correlations between active bacterial and eukaryotic community structures. This study suggests that earthworms can decrease the diversity of bacterial and eukaryotic communities, forming a specific-functional microbial community and thus accelerating organic matter decomposition during vermicomposting of dewatered sludge.
对参与蚯蚓堆肥的活性细胞进行 DNA 测序，可以阐明蚯蚓在调节功能微生物方面的作用。本研究旨在通过比较有无蚯蚓的生物降解处理，来研究蚯蚓对污泥功能微生物群落的影响。通过预处理吖啶橙（PMA）的 PCR 和高通量测序，检测蚯蚓堆肥过程中活性细菌 16S rDNA 和真核生物 18S rDNA 的变化。结果表明，污泥蚯蚓堆肥和对照中的硝酸盐在第 10 天有明显差异，第 30 天堆肥产物更稳定。与对照相比，污泥蚯蚓堆肥中的活性细菌和真核生物的 Shannon 指数分别下降了 1.9%和 31.1%。此外，污泥蚯蚓堆肥中活性细菌的优势门为变形菌门（36.2%），放线菌门（25.6%）和真核生物隐真菌门（80.3%）被激活。相比之下，对照中优势门为变形菌门（44.8%），拟杆菌门（14.2%），隐真菌门（50.00%）和节肢动物门（36.59%）。网络分析表明，环境因子与活性细菌和真核生物群落结构之间存在不同的相关性。本研究表明，蚯蚓可以降低细菌和真核生物群落的多样性，形成特定功能的微生物群落，从而加速脱水污泥蚯蚓堆肥过程中有机物的分解。
