LCR-Pilze - Analysis of the contribution of aerobic fungi to biogas production

Subproject 2: Contribution analysis of aerobic fungi

The use of lignocellulose-rich residues such as straw in biogas plants poses a major challenge, as the high lignin content inhibits microbial degradation and reduces biogas production. In this collaborative project, the Bavarian State Research Center for Agriculture (LfL), the Technical University of Munich (TUM), and INNOVAS BMK GmbH are investigating the use of fungi to improve substrate processing and process stability. Anaerobic and aerobic fungi are tested in a specially constructed pilot-scale biogas plant and monitored through comprehensive process analytics, including gas and fiber analysis as well as molecular and multi-omics approaches.

Subproject 1: Anaerobic Fungi (lead: LfL)

Anaerobic fungi possess the greatest diversity of lignocellulose-degrading enzymes among fungi and can break down plant biomass both enzymatically and mechanically. The goal is to establish a continuously anaerobic fungal culture for the hydrolytic pretreatment of lignocellulose-rich residues. This will improve accessibility for microbial degradation and increase biogas production efficiency. LfL is responsible for the micro- and molecular biological work in this subproject and is developing strategies for long-term integration into the biogas process.

Subproject 2: Aerobic Fungi (lead: TUM)

This subproject investigates the impact of aerobic fungi such as Trichoderma species as a pretreatment to enhance straw hydrolysis and reduce mechanical disturbances in fermenters with high straw content. During trials in the pilot-scale biogas plant, data on process chemistry as well as meta-genomes, meta-transcriptomes, and proteomes will be collected to obtain a comprehensive picture of Trichoderma’s influence on hydrolysis and overall biogas production. Digestate produced during the biogas process will be further treated in composting boxes using aerobic brown- and white-rot fungi to release residual sugars for reuse in the anaerobic fermenter. These post-treated digestates will be reintroduced into the biogas process, and their remaining potential will be quantified.

 

Publications

• Young, D., Dollhofer, V., Callaghan, T. M., Reitberger, S., Lebuhn, M., & Benz, J. P. (2018). Isolation, identification and characterization of lignocellulolytic aerobic and anaerobic fungi in one- and two-phase biogas plants. Bioresource Technology, 268, 470-479. doi:https://doi.org/10.1016/j.biortech.2018.07.103