Robert Boyle Institut e.V., Jena, Germany; Technische Universität Dresden, Chair of Waste Management, Pratzschwitzer Str. 15, Pirna, Germany.
Darwin Bioprospecting Excellence, S.L., Paterna, Valencia, Spain.
Syst Appl Microbiol. 2020 Jan;43(1):126024. doi: 10.1016/j.syapm.2019.126024. Epub 2019 Oct 19.
Conventional anaerobic digesters intended for the production of biogas usually operate in complete darkness. Therefore, little is known about the effect of light on their microbial communities. In the present work, 16S rRNA gene amplicon Nanopore sequencing and shotgun metagenomic sequencing were used to study the taxonomic and functional structure of the microbial community forming a biofilm on the inner wall of a laboratory-scale transparent anaerobic biodigester illuminated with natural sunlight. The biofilm was composed of microorganisms involved in the four metabolic processes needed for biogas production, and it was surprisingly rich in Rhodopseudomonas faecalis, a versatile bacterium able to carry out photoautotrophic metabolism when grown under anaerobic conditions. The results suggested that this bacterium, which is able to fix carbon dioxide, could be considered for use in transparent biogas fermenters in order to contribute to the production of optimized biogas with a higher CH:CO ratio than the biogas produced in regular, opaque digesters. To the best of our knowledge, this is the first study characterising the phototrophic biofilm associated with illuminated bioreactors.
传统的用于生产沼气的厌氧消化器通常在完全黑暗的环境中运行。因此，人们对光照对其微生物群落的影响知之甚少。在本工作中，我们使用 16S rRNA 基因扩增子纳米孔测序和 shotgun 宏基因组测序来研究在自然光照射下的实验室规模透明厌氧生物消化器内壁形成生物膜的微生物群落的分类和功能结构。生物膜由参与沼气生产所需的四个代谢过程的微生物组成，令人惊讶的是，其中富含 Rhodopseudomonas faecalis，这是一种多功能细菌，在厌氧条件下生长时能够进行光自养代谢。结果表明，这种能够固定二氧化碳的细菌可以考虑用于透明沼气发酵器中，以有助于生产优化的沼气，其 CH:CO 比高于常规不透明消化器中产生的沼气。据我们所知，这是首次对与光照生物反应器相关的光养生物膜进行特征描述的研究。
