Galitskaya Polina, Biktasheva Liliya, Saveliev Anatoly, Grigoryeva Tatiana, Boulygina Eugenia, Selivanovskaya Svetlana
Department of Applied Ecology, Institute of Environmental Sciences, Kazan Federal University, Kazan, Russian Federation.
Department of Ecological Systems Modeling, Institute of Environmental Sciences, Kazan Federal University, Kazan, Russian Federation.
PLoS One. 2017 Oct 23;12(10):e0186051. doi: 10.1371/journal.pone.0186051. eCollection 2017.
Composting is viewed as one of the primary methods to treat organic wastes. Co-composting may improve the efficiency of this treatment by establishing the most suitable conditions for decomposers than those present in the individual wastes. Given that bacteria and fungi are the driving agents of composting, information about the composition of their communities and dynamics during composting may improve reproducibility, performance and quality of the final compost as well as help to evaluate the potential human health risk and the choice of the most appropriate application procedure. In this study, the co-composting of mixtures containing two similar components (organic fraction of municipal solid waste and sawdust polluted by oil) and one discriminate component (sewage sludges of different origin) were investigated. Bacterial and fungal community successions in the two mixtures were analyzed during the composting process by determining the change in their structural dynamics using qPCR and 454 pyrosequencing methods in a lab experiment for a period of 270 days. During the initial composting stage, the number of 16S bacterial copies was (3.0±0.2) x 106 and (0.4±0.0) x 107 g-1, and the Rhodospiralles and Lactobacialles orders dominated. Fungal communities had (2.9±0.0) x105 and (6.1±0.2) x105 ITS copies g-1, and the Saccharomycetales order dominated. At the end of the thermophilic stage on the 30th day of composting, bacterial and fungal communities underwent significant changes: dominants changed and their relative abundance decreased. Typical compost residents included Flavobacteriales, Chitinophagaceae and Bacterioidetes for bacteria and Microascaceae, Dothideomycetes, Eurotiomycetes, Sordariomycetes, and Agaricomycetes for fungi. During the later composting stages, the dominating taxa of both bacterial and fungal communities remained, while their relative abundance decreased. In accordance with the change in the dominating OTUs, it was concluded that the dynamics of the bacterial and fungal communities were not similar. Analysis by non-metric multidimensional scaling (NMDS) revealed that the bacterial communities of the two composts became progressively more similar; a similar trend was followed by the fungal community.
堆肥被视为处理有机废物的主要方法之一。与单独的废物相比，共堆肥可以通过为分解者创造最适宜的条件来提高这种处理方法的效率。鉴于细菌和真菌是堆肥的驱动因素，了解它们在堆肥过程中的群落组成和动态信息，可能会提高最终堆肥的可重复性、性能和质量，同时有助于评估潜在的人类健康风险以及选择最合适的应用程序。在本研究中，对含有两种相似成分（城市固体废物有机部分和受油污染的锯末）和一种有区别成分（不同来源的污水污泥）的混合物进行了共堆肥研究。在实验室为期270天的实验中，通过使用qPCR和454焦磷酸测序方法确定两种混合物在堆肥过程中细菌和真菌群落结构动态的变化，分析了细菌和真菌群落的演替。在堆肥初期，16S细菌拷贝数分别为(3.0±0.2)×10⁶和(0.4±0.0)×10⁷ g⁻¹，以红螺菌目和乳杆菌目为主。真菌群落的ITS拷贝数分别为(2.9±0.0)×10⁵和(6.1±0.2)×10⁵ g⁻¹，以酵母目为主。在堆肥第30天嗜热阶段结束时，细菌和真菌群落发生了显著变化：优势菌群改变，其相对丰度下降。典型的堆肥微生物包括细菌中的黄杆菌目、噬几丁质菌科和拟杆菌门，以及真菌中的小囊菌科、座囊菌纲、散囊菌纲、粪壳菌纲和伞菌纲。在堆肥后期，细菌和真菌群落的优势分类群仍然存在，但其相对丰度下降。根据优势OTU的变化得出结论，细菌和真菌群落的动态并不相似。非度量多维标度分析（NMDS）表明，两种堆肥的细菌群落逐渐变得更加相似；真菌群落也呈现出类似的趋势。
