Institute of Microbiology and Biotechnology, Ulm University, Ulm, Germany.
Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany.
Microb Biotechnol. 2019 Nov;12(6):1210-1225. doi: 10.1111/1751-7915.13409. Epub 2019 Apr 17.
Biogas production is a biotechnological process realized by complex bacterial, archaeal and likely fungal communities. Their composition was assessed in nine full-scale biogas plants with distinctly differing feedstock input and process parameters. This study investigated the actually active microbial community members by using a comprehensive sequencing approach based on ribosomal 16S and 28S rRNA fragments. The prevailing taxonomical units of each respective community were subsequently linked to process parameters. Ribosomal rRNA of bacteria, archaea and fungi, respectively, showed different compositions with respect to process parameters and supplied feedstocks: (i) bacterial communities were affected by the key factors temperature and ammonium concentration; (ii) composition of archaea was mainly related to process temperature; and (iii) relative abundance of fungi was linked to feedstocks supplied to the digesters. Anaerobic digesters with a high methane yield showed remarkably similar bacterial communities regarding identified taxonomic families. Although archaeal communities differed strongly on genus level from each other, the respective digesters still showed high methane yields. Functional redundancy of the archaeal communities may explain this effect. 28S rRNA sequences of fungi in all nine full-scale anaerobic digesters were primarily classified as facultative anaerobic Ascomycota and Basidiomycota. Since the presence of ribosomal 28S rRNA indicates that fungi may be active in the biogas digesters, further research should be carried out to examine to which extent they are important players in anaerobic digestion processes.
沼气生产是一个由复杂的细菌、古菌和可能的真菌群落实现的生物技术过程。它们的组成在九个具有明显不同进料和工艺参数的大型沼气厂中进行了评估。本研究通过基于核糖体 16S 和 28S rRNA 片段的综合测序方法，研究了实际活跃的微生物群落成员。随后将各个群落的主要分类单元与工艺参数联系起来。细菌、古菌和真菌的核糖体 rRNA 分别在工艺参数和供应的饲料方面表现出不同的组成：（i）细菌群落受关键因素温度和氨浓度的影响；（ii）古菌的组成主要与工艺温度有关；（iii）真菌的相对丰度与消化器中供应的饲料有关。甲烷产量高的厌氧消化器在确定的分类家族方面具有非常相似的细菌群落。尽管在属水平上，古菌群落彼此之间存在很大差异，但各自的消化器仍表现出高的甲烷产量。古菌群落的功能冗余可能解释了这一效应。在所有九个大型厌氧消化器中，真菌的 28S rRNA 序列主要被分类为兼性厌氧的子囊菌门和担子菌门。由于核糖体 28S rRNA 的存在表明真菌可能在沼气消化器中活跃，因此应该进行进一步的研究，以检查它们在厌氧消化过程中重要程度。
