Project description:There is a wide diversity of potential applications for direct electron transfer from electrodes to microorganisms, which might be better optimized if the mechanisms for this novel electrode-biofilm interaction were better understood. Geobacter sulfurreducens is one of the few microorganisms available in pure culture that is known to be capable of directly accepting electrons from a negatively poised electrode. A microarray comparison of cells accepting electrons from the electrode versus cells donating electrons to the electrode reveals that the genes previously observed to be upregulated in current-producing biofilms are not highly expressed in current-consuming biofilms.
2010-11-23 | GSE19150 | GEO
Project description:Enhanced methane production in microbial electrolysis cell coupled anaerobic digestion system with MXene accelerants
Project description:Investigation of whole genome gene expression level changes in a Shewanella oneidensis MR-1 to Fe nanoparticle decorated anodes, compared to the carbon plate anodes in microbial electrolysis cells. Whole genome microarray analysis of the gene expression showed that the encoding biofilm formation genes were significantly up-regulated as response to nanoparticle decorated anodes which indicated thickness improvements contributed to enhance current density. The increased expression genes related to nanowire, flavins and c-type cytochromes also have partially contributed to enhance current density by Fe nanoparticle decorated anode. The majority of additional differentially expressed genes associated with electron transport, anaerobic metabolism in response to the nanostructured anodes possibly play roles in current density enhancement.
Project description:Anaerobic digestion is a popular and effective microbial process for waste treatment. The performance of anaerobic digestion processes is contingent on the balance of the microbial food web in utilizing various substrates. Recently, co-digestion, i.e., supplementing the primary substrate with an organic-rich co-substrate has been exploited to improve waste treatment efficiency. Yet the potential effects of elevated organic loading on microbial functional gene community remains elusive. In this study, functional gene array (GeoChip 5.0) was used to assess the response of microbial community to the addition of poultry waste in anaerobic digesters treating dairy manure. Consistent with 16S rRNA gene sequences data, GeoChip data showed that microbial community compositions were significantly shifted in favor of copiotrophic populations by co-digestion, as taxa with higher rRNA gene copy number such as Bacilli were enriched. The acetoclastic methanogen Methanosarcina was also enriched, while Methanosaeta was unaltered but more abundant than Methanosarcina throughout the study period. The microbial functional diversity involved in anaerobic digestion were also increased under co-digestion.
Project description:There is a wide diversity of potential applications for direct electron transfer from electrodes to microorganisms, which might be better optimized if the mechanisms for this novel electrode-biofilm interaction were further understood. Geobacter sulfurreducens is one of the few microorganisms available in pure culture that is known to be capable of directly accepting electrons from a negatively poised electrode. Gene transcript abundance in cells of G. sulfurreducens using electrons delivered from a graphite electrode as the sole electron donor for fumarate reduction was compared with transcript abundance in cells growing on the same graphite material, but without an electrical connection and acetate as the electron donor.
Project description:Investigation of whole genome gene expression level changes in a Shewanella oneidensis MR-1 to Fe nanoparticle decorated anodes, compared to the carbon plate anodes in microbial electrolysis cells. Whole genome microarray analysis of the gene expression showed that the encoding biofilm formation genes were significantly up-regulated as response to nanoparticle decorated anodes which indicated thickness improvements contributed to enhance current density. The increased expression genes related to nanowire, flavins and c-type cytochromes also have partially contributed to enhance current density by Fe nanoparticle decorated anode. The majority of additional differentially expressed genes associated with electron transport, anaerobic metabolism in response to the nanostructured anodes possibly play roles in current density enhancement. A six chip study using total RNA recovered from three separate replicates of biofilm on Fe Nanoparticle decorated anode of Shewanella oneidensis MR-1 and three separate replicates of carbon plate control. Each chip measures the expression level of 4,295 genes .
Project description:This project focust on proteogenomic characterization of a robust low complexity biocathode community which was enriched from, and cultivated on, the cathode of a microbial solar cell (MSC). This consortium forms a multi-cell layer thick biofilm on the poised electrode surface (+310 mV SHE) and can directly use electrical current as an electron donor to fix CO2 and reduce O2.