Wolters Birgit, Ding Guo-Chun, Kreuzig Robert, Smalla Kornelia
Julius Kühn-Institut, Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, 38104 Braunschweig, Germany Institute of Environmental and Sustainable Chemistry, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
College of Resources and Environmental Science, China Agricultural University, 100094 Beijing, China.
FEMS Microbiol Ecol. 2016 Feb;92(2). doi: 10.1093/femsec/fiv163. Epub 2016 Jan 14.
The application of manure, typically harboring bacteria carrying resistance genes (RGs) and mobile genetic elements (MGEs), as co-substrate in biogas plants (BGPs) might be critical when digestates are used as fertilizers. In the present study, the relative abundance of RGs and MGEs in total community (TC-) DNA from manure, fermenters and digestate samples taken at eight full-scale BGPs co-fermenting manure were determined by real-time PCR. In addition, the bacterial community composition of all digestates as well as manure and fermenter material from one BGP (BGP3) was characterized by 454-pyrosequencing of 16S rRNA amplicons from TC-DNA. Compared to respective input manures, relative abundances determined for sul1, sul2, tet(M), tet(Q), intI1, qacEΔ1, korB and traN were significantly lower in fermenters, whereas relative abundances of tet(W) were often higher in fermenters. The bacterial communities in all digestates were dominated by Firmicutes and Bacteroidetes while Proteobacteria were low in abundance and no Enterobacteriaceae were detected. High-throughput sequencing revealed shifts in bacterial communities during treatment for BGP3. Although in comparison to manure, digestate bacteria had lower relative abundances of RGs and MGEs except for tet(W), mesophilic BGPs seem not to be effective for prevention of the spread of RGs and MGEs via digestates into arable soils.
当沼渣用作肥料时，将通常含有携带抗性基因（RGs）和可移动遗传元件（MGEs）的细菌的粪便作为沼气厂（BGPs）的共底物使用可能至关重要。在本研究中，通过实时PCR测定了来自八个共同发酵粪便的全规模沼气厂的粪便、发酵罐和沼渣样品的总群落（TC-）DNA中RGs和MGEs的相对丰度。此外，通过对来自TC-DNA的16S rRNA扩增子进行454焦磷酸测序，对一个沼气厂（BGP3）的所有沼渣以及粪便和发酵罐物料的细菌群落组成进行了表征。与各自的输入粪便相比，发酵罐中sul1、sul2、tet（M）、tet（Q）、intI1、qacEΔ1、korB和traN的相对丰度显著降低，而发酵罐中tet（W）的相对丰度通常较高。所有沼渣中的细菌群落以厚壁菌门和拟杆菌门为主，变形菌门丰度较低，未检测到肠杆菌科。高通量测序揭示了BGP3处理过程中细菌群落的变化。尽管与粪便相比，除tet（W）外，沼渣细菌中RGs和MGEs的相对丰度较低，但中温沼气厂似乎对防止RGs和MGEs通过沼渣传播到耕地土壤中无效。
