100 documents found, page 1 of 10
Hydrogenotrophic activity under increased H₂/CO₂ pressure: effect on methane pr...
Lopes, Marlene; Alves, J. I.; Pereira, A.; Belo, Isabel; Sousa, D. Z.; Alves, M. M.H2 and CO2 are main compounds of synthesis gas. Efficient conversion of syngas to biomethane is a straightforward strategy to integrate the energy value of syngas into existing natural gas grid infrastructures. In this study, the effect of initial H2/CO2 (80/20, v/v) pressure on methane production rate and microbial community diversity was assessed in a hyperbaric bioreactor inoculated with anaerobic granular s...
Anaerobic co-digestion of cork based oil sorbent and cow manure or sludge
Cavaleiro, A. J.; Neves, T. M.; Guedes, Ana P.; Alves, M. M.; Pinto, P.; Silva, S. P.; Sousa, D. Z.Cork, a material with great economic, social and environmental importance in Portugal, is also a good oil sorbent that can be used in the remediation of oil spills. The oil-impregnated cork can be easily removed, but requires further treatment. In the case of vegetable oil spills, anaerobic digestion may be a potential solution. This study aims to evaluate the effect of adding cork contaminated with sunflower o...
Enrichment of carbon monoxide utilising microorganisms from methanogenic biorea...
Pereira, Ana Luísa; Stams, Alfons Johannes Maria; Alves, M. M.; Sousa, D. Z.Conversion of CO is the rate limiting step during anaerobic conversion of syngas (a gaseous mixture mainly composed of CO, CO2 and H2). In this work we study the microbial diversity in anaerobic sludge submitted to extended contact to syngas in a multi-orifice baffled bioreactor (MOBB). Methane was the main product resulting from syngas conversion in the MOBB. Enrichment cultures started with this sludge produc...
Meta-omics approaches to understand and improve wastewater treatment systems
Rodríguez, Elisa; García-Encina, Pedro A.; Stams, Alfons Johannes Maria; Maphosa, Farai; Sousa, D. Z.Biological treatment of wastewaters depends on microbial processes, usually carried out by mixed microbial communities. Environmental and operational factors can affect microorganisms and/or impact microbial community function, and this has repercussion in bioreactor performance. Novel high-throughput molecular methods (metagenomics, metatranscriptomics, metaproteomics, metabolomics) are providing detailed know...
Characterization of an anaerobic thermophilic glycerol-degrading enrichment cul...
Cavaleiro, A. J.; Sousa, D. Z.; Alves, M. M.; Stams, Alfons Johannes MariaBackground: The glycerol market was totally changed by the biodiesel industry, which resulted in the production of an excess of this compound as an industrial by-product. As a consequence, the price of glycerol dropped and a huge interest in alternatives for its valorisation emerged since then. In the field of Biotechnology research, glycerol is an attractive compound for the microbial production of chemical bu...
Methanogens, sulphate and heavy metals: a complex system
Paulo, Lara M.; Stams, Alfons Johannes Maria; Sousa, D. Z.Anaerobic digestion (AD) is a well-established technology used for the treatment of wastes and wastewaters with high organic content. During AD organic matter is converted stepwise to methane-containing biogasa renewable energy carrier. Methane production occurs in the last AD step and relies on methanogens, which are rather sensitive to some contaminants commonly found in wastewaters (e.g. heavy metals), or ea...
Pathways and bioenergetics of anaerobic carbon monoxide fermentation
Diender, Martijn; Stams, Alfons Johannes Maria; Sousa, D. Z.Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the potential of converting CO-rich gas, such as synthesis gas, into bio-based products. Three main types of fermentative CO m...
Proteomics of Syntrophomonas zehnderi and Methanobacterium formicicum growing o...
Salvador, A. F.; Strepis, N.; Bize, A.; Stams, Alfons Johannes Maria; Schaap, Peter J.; Alves, M. M.; Bouchez, T.; Sousa, D. Z.Background: Conversion of long-chain fatty acids (LCFA) in anaerobic digesters relies on syntrophic relationship between acetogenic bacteria and methanogenic archaea. Conversion of unsaturated- and saturated-LCFA has been previously shown by a coculture of Syntrophomonas zehnderi and Methanobacterium formicium. Degradation of unsaturated-LCFA is rare among Syntrophomonas species; the best studied fatty acid oxi...
Novel anaerobe obtained from a hexadecane-degrading consortium
Alves, J. I.; Salvador, A. F.; Langenhoff, A. A. M.; Stams, Alfons Johannes Maria; Alves, M. M.; Sousa, D. Z.; Cavaleiro, A. J.Background: Aliphatic hydrocarbons (AHC) are abundant in crude oil and fuels, and are frequent contaminants of water, soil and sediments. There is potential for AHC bioremediation using sulfate as electron acceptor, due to its abundance in marine environments and natural presence in soils and groundwater. Objectives: In this work sulfate-reducing anaerobic microorganisms involved in AHC biodegradation were stud...
Enrichment of carbon monoxide utilising microorganisms from methanogenic biorea...
Pereira, Ana Luísa; Stams, Alfons Johannes Maria; Alves, M. M.; Sousa, D. Z.Conversion of CO is the rate limiting step during anaerobic conversion of syngas (a gaseous mixture mainly composed of CO, CO2 and H2). In this work we study the microbial diversity in anaerobic sludge submitted to extended contact to syngas in a multi-orifice baffled bioreactor (MOBB). Methane was the main product resulting from syngas conversion in the MOBB. Enrichment cultures started with this sludge produc...