Bioaugmentation by enriched hydrogenotrophic methanogens into trickle bed reactors for H₂/CO₂ conversion.

Area of Science:

• Biotechnology
• Environmental Science
• Microbiology

Background:

• Biomethanation is key for biomethane production, with trickle bed reactors (TBRs) showing high efficiency.
• Maintaining stable performance in TBRs is challenging, prompting research into bioaugmentation strategies.
• Hydrogenotrophic methanogens are crucial for converting CO2 and H2 into methane.

Purpose of the Study:

• To evaluate the impact of bioaugmentation with hydrogenotrophic methanogens on TBR performance.
• To analyze microbial community dynamics in bioaugmented TBRs.
• To assess the potential for establishing specific methanogen populations in biofilms.

Main Methods:

• Bioaugmentation of TBRs using inocula enriched with hydrogenotrophic methanogens.
• Metagenomic analysis to identify dominant microbial species and community structure.
• Monitoring of biogas production and composition (methane content).
• Assessment of hydrogen (H2) consumption.

Main Results:

• Successful colonization of TBR biofilms by the hydrogenotrophic genus Methanobacterium after bioaugmentation.
• Biogas production consistently exceeded 96% methane.
• Increased consumption of H2 in the bioaugmented reactor, suggesting diverse CO2 reduction pathways.
• Demonstrated potential for establishing targeted microbial species.

Conclusions:

• Bioaugmentation is a viable strategy for enhancing biomethane production in TBRs by introducing specific methanogenic communities.
• The study highlights the dominance of Methanobacterium and increased H2 utilization.
• Further research is needed to optimize microbial interactions and manage H2 consumption for improved process stability.