0000000000299158
AUTHOR
Claudia Simeonov
Shedding light on biogas: a transparent reactor triggers the development of a biofilm dominated by Rhodopseudomonas faecalis that holds potential for improved biogas production
AbstractConventional anaerobic digesters intended for the production of biogas usually operate in complete darkness. Therefore, little is known about the effect of light on microbial communities operating in anaerobic digesters. In the present work, we have studied through 16S rRNA gene amplicon Nanopore sequencing and shotgun metagenomic sequencing the taxonomic and functional structure of the microbial community forming a biofilm on the inner wall of a lab-scale transparent anaerobic biodigester illuminated with natural sunlight. The biofilm was composed of microorganisms involved in the four metabolic processes needed for biogas production. The biofilm proved surprisingly rich in Rhodops…
Microbial communities involved in biogas production exhibit high resilience to heat shocks
We report here the impact of heat-shock treatments (55 and 70 °C) on the biogas production within the acidification stage of a two-stage reactor system for anaerobic digestion and biomethanation of grass. The microbiome proved both taxonomically and functionally very robust, since heat shocks caused minor community shifts compared to the controls, and biogas yield was not decreased. The strongest impact on the microbial profile was observed with a combination of heat shock and low pH. Since no transient reduction of microbial diversity occured after the shock, biogas keyplayers, but also potential pathogens, survived the treatment. All along the experiment, the heat-resistant bacterial prof…
MOESM7 of From grass to gas: microbiome dynamics of grass biomass acidification under mesophilic and thermophilic temperatures
Additional file 7: Table S7. Number of reads and mean length of reads for bacteria from the methane stages.
MOESM8 of From grass to gas: microbiome dynamics of grass biomass acidification under mesophilic and thermophilic temperatures
Additional file 8: Table S8. Number of reads and mean length of reads for archaea from the methane stages.
Liquid co-substrates repower sewage microbiomes
AbstractA range of parameters are known to shape the methanogenic communities of biogas-producing digesters and to strongly influence the amount of biogas produced. In this work, liquid and solid fractions of grass biomass were used separately for semicontinuous batch methanation using sewage sludge as seed sludge. During 6 months of incubation, the amount of input COD was increased gradually, and the underlying methanogenic microbiome was assessed by means of microscopy-based automated cell counting and full-length 16S rRNA high-throughput sequencing. In this sense, we prove for the first time the suitability of the ONT™MinION platform as a monitoring tool for anaerobic digestion systems. …
MOESM3 of From grass to gas: microbiome dynamics of grass biomass acidification under mesophilic and thermophilic temperatures
Additional file 1: Figure S3. SDS-PAGE displaying the protein profiles.
Shedding light on biogas: Phototrophic biofilms in anaerobic digesters hold potential for improved biogas production
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…
MOESM2 of From grass to gas: microbiome dynamics of grass biomass acidification under mesophilic and thermophilic temperatures
Additional file 5: Table S2. Overview of reaction stages and reactor performance.
MOESM1 of From grass to gas: microbiome dynamics of grass biomass acidification under mesophilic and thermophilic temperatures
Additional file 4: Table S1. Description of the used seed sludge.
MOESM6 of From grass to gas: microbiome dynamics of grass biomass acidification under mesophilic and thermophilic temperatures
Additional file 6: Table S6. Number of sequences and mean length for bacteria from the acidification stages.
From grass to gas: microbiome dynamics of grass biomass acidification under mesophilic and thermophilic temperatures
Background Separating acidification and methanogenic steps in anaerobic digestion processes can help to optimize the process and contribute to producing valuable sub-products such as methane, hydrogen and organic acids. However, the full potential of this technology has not been fully explored yet. To assess the underlying fermentation process in more detail, a combination of high-throughput sequencing and proteomics on the acidification step of plant material (grass) at both mesophilic and thermophilic temperatures (37 and 55 °C, respectively) was applied for the first time. Results High-strength liquor from acidified grass biomass exhibited a low biodiversity, which differed greatly depen…
MOESM4 of From grass to gas: microbiome dynamics of grass biomass acidification under mesophilic and thermophilic temperatures
Additional file 2: Table S4. Mascot results.
MOESM5 of From grass to gas: microbiome dynamics of grass biomass acidification under mesophilic and thermophilic temperatures
Additional file 3: Table S5. Differentially expressed proteins.