Acclimatised rumen culture for raw microalgae conversion into biogas: Linking microbial community structure and operational parameters in anaerobic membrane bioreactors (AnMBR)

• Published in: Bioresource technology 2019-10, Vol.290, p.121787-121787, Article 121787
• Main Authors: Zamorano-López, Núria, Borrás, Luis, Giménez, Juan B., Seco, Aurora, Aguado, Daniel
• Format: Article
• Language: English
• Subjects: 16S rRNA gene; Anaerobic membrane bioreactor (AnMBR); Biogas; Microalgae; Rumen
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121787

[Display omitted] •Solids retention time and organic loading rate shaped microbial structure.•Fervidobacterium and Methanosaeta were key during raw Scenedesmus degradation.•Hydrolytic and syntrophic groups were also enhanced from rumen inoculum.•The robust microbial community was linked to a 62% biodegradability. Ruminal fluid was inoculated in an Anaerobic Membrane Reactor (AnMBR) to produce biogas from raw Scenedesmus. This work explores the microbial ecology of the system during stable operation at different solids retention times (SRT). The 16S rRNA amplicon analysis revealed that the acclimatised community was mainly composed of Anaerolineaceae, Spirochaetaceae, Lentimicrobiaceae and Cloacimonetes fermentative and hydrolytic members. During the highest biodegradability achieved in the AnMBR (62%) the dominant microorganisms were Fervidobacterium and Methanosaeta. Different microbial community clusters were observed at different SRT conditions. Interestingly, syntrophic bacteria Gelria and Smithella were enhanced after increasing 2-fold the organic loading rate, suggesting their importance in continuous systems producing biogas from raw microalgae.