0000000000464060
AUTHOR
Sarah Hahnke
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…
Complete Genome Sequence of a New Firmicutes Species Isolated from Anaerobic Biomass Hydrolysis
ABSTRACT A new Firmicutes isolate, strain HV4-6-A5C, was obtained from the hydrolysis stage of a mesophilic and anaerobic two-stage lab-scale leach-bed system for biomethanation of fresh grass. It is assumed that the bacterial isolate contributes to plant biomass degradation. Here, we report a draft annotated genome sequence of this organism.
Complete Genome Sequence of a New Clostridium sp. Isolated from Anaerobic Digestion and Biomethanation
Here, we present the genome sequence and annotation of the bacterial strain HV4-5-A1G, a potentially new Clostridium species. Based on its genomic data, this strain may act as a keystone microorganism in the hydrolysis of complex polymers, as well as in the different acidogenesis and acetogenesis steps during anaerobic digestion.
Complete Genome Sequence of a New Ruminococcaceae Bacterium Isolated from Anaerobic Biomass Hydrolysis
ABSTRACT A new Ruminococcaceae bacterium, strain HV4-5-B5C, participating in the anaerobic digestion of grass, was isolated from a mesophilic two-stage laboratory-scale leach bed biogas system. The draft annotated genome sequence presented in this study and 16S rRNA gene sequence analysis indicated the affiliation of HV4-5-B5C with the family Ruminococcaceae outside recently described genera.
Potential pitfalls of FISH microscopy as assessment method for anaerobic digesters
AbstractIn the present work we investigated how the state of a biogas reactor impacts the enumeration of prokaryotic cells by fluorescencein situhybridisation (FISH). Therefore, the correlation between gas production and FISH hybridisation rates was analysed in different anaerobic digester sludges. High gasification activity coincided with high hybridisation rates. Low hybridisation rates were especially achieved with reactor samples subjected to long starvation periods showing low biogas production.Based on our findings we conclude that samples for FISH analysis should be fixed as soon as possible to prevent a loss of microbial activity resulting in lower FISH signals. Furthermore, the loc…
Complete genome sequence of a new Bacteroidaceae bacterium isolated from anaerobic biomass digestion
Here, we present the genome sequence and annotation of HV4-6-C5C, a bacterial strain isolated from a mesophilic two-stage laboratory-scale leach bed biogas reactor system. Strain HV4-6-C5C may represent a new genus of the family Bacteroidaceae and may have a key role in acidogenesis and acetogenesis steps during anaerobic biomass digestion.