Abstract

The use of straw for biofuel production is encouraged by the European Union. A previous study showed the feasibility of producing biomethane in upflow anaerobic sludge blanket (UASB) reactors using hydrolyzed, steam-pretreated wheat straw, before and after dark fermentation withCaldicellulosiruptor saccharolyticus, and lucerne. This study provides information on overall microbial community development in those UASB processes and changes related to acidification. The bacterial and archaeal community in granular samples was analyzed using high-throughput amplicon sequencing. Anaerobic digestion model no. 1 (ADM1) was used to predict the abundance of microbial functional groups. The sequencing results showed decreased richness and diversity in the microbial community, and decreased relative abundance of bacteria in relation to archaea, after process acidification. Canonical correspondence analysis showed significant negative correlations between the concentration of organic acids and three phyla, and positive correlations with seven phyla. Organic loading rate and total COD fed also showed significant correlations with microbial community structure, which changed over time. ADM1 predicted a decrease in acetate degraders after a decrease to pH <= 6.5. Acidification had a sustained effect on the microbial community and process performance.

Keywords

wheat straw hydrolysate; microbial community; next-generation amplicon sequencing; UASB; ADM1; process acidification; methane production; VFA

Published in

Microorganisms
2020, Volume: 8, number: 9, article number: 1394
Publisher: MDPI

SLU Authors

• Liu, Tong

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

• Schnürer, Anna

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Microbiology


Publication identifier

DOI: https://doi.org/10.3390/microorganisms8091394

Permanent link to this page (URI)

https://res.slu.se/id/publ/108677