Duan Y-F, Al-Soud W A, Brejnrod A, Sørensen S J, Elsgaard L, Petersen S O, Boon N
Department of Agroecology, Aarhus University, Tjele, Denmark.
J Appl Microbiol. 2014 Oct;117(4):1066-78. doi: 10.1111/jam.12584. Epub 2014 Jul 14.
Crusts forming at the surface of liquid manure (slurry) during storage have been shown to harbour a potential for mitigating CH4 emissions. This study investigated the microbial community in surface crusts, with a focus on micro-organisms related to CH4 metabolism.
Microbial communities in four crusts from cattle and swine slurries were investigated using denaturing gradient gel electrophoresis and tag-encoded amplicon pyrosequencing. All crusts had distinct compositions of bacteria and archaea. The genera Methylobacter, Methylomicrobium, Methylomonas, and Methylosarcina of Type I, and Methylocystis of Type II, dominated the methane-oxidizing bacteria (MOB) community, whereas Methanocorpusculum was the predominant methanogen. Higher numbers of operational taxonomic units (OTUs) representing Type I than Type II MOB were found in all crusts. Potential CH4 oxidation rates were determined by incubating crusts with CH4 , and CH4 oxidization was observed in cattle, but not in swine slurry crusts.
Slurry surface crusts harbour a diverse microbial community. Type I MOB are more diverse and abundant than Type II MOB in this environment. The distinct CH4 oxidation rates could be related to microbial compositions.
This study is the first to present the overall microbial community structure in slurry surface crusts. A better understanding of microbial community in surface crusts could support strategies for mitigation of CH4 emissions from livestock manure management.
研究表明，液态粪肥（ slurry ）储存期间在表面形成的硬壳具有缓解甲烷排放的潜力。本研究调查了表面硬壳中的微生物群落，重点关注与甲烷代谢相关的微生物。
利用变性梯度凝胶电泳和标签编码扩增子焦磷酸测序技术，对来自牛和猪粪便的四种硬壳中的微生物群落进行了研究。所有硬壳的细菌和古菌组成都不同。I型的甲基杆菌属、甲基微菌属、甲基单胞菌属和甲基八叠球菌属，以及II型的甲基孢囊菌属，主导了甲烷氧化细菌（MOB）群落，而甲烷小体属是主要的产甲烷菌。在所有硬壳中，代表I型MOB的可操作分类单元（OTU）数量均高于II型MOB。通过将硬壳与甲烷一起孵育来测定潜在的甲烷氧化速率，在牛粪硬壳中观察到了甲烷氧化，但在猪粪硬壳中未观察到。
粪肥表面硬壳含有多样的微生物群落。在这种环境中I型MOB比II型MOB更多样化且更丰富。不同的甲烷氧化速率可能与微生物组成有关。
本研究首次展示了粪肥表面硬壳中的整体微生物群落结构。更好地了解表面硬壳中的微生物群落可以支持减轻畜牧粪便管理中甲烷排放的策略。
