16 documents found, page 1 of 2
Enhanced glycerol conversion by Thermoanaerobacter strains
Magalhães, Carla Isabel Pereira; Ribeiro, Joaquim Alfredo França Martins; Guedes, Ana P.; Arantes, Ana Luísa; Sousa, Diana Zita MachadoGlycerol-rich waste streams produced as a surplus by the biodiesel industry can be treated and valorized by anaerobic microbial communities to produce biogas. Glycerol is a highly reduced compound. Its complete degradation to methane and carbon dioxide requires a syntrophic cooperation of anaerobic bacteria and archaea, either directly or through propionate, lactate or ethanol as intermediates. The aim of this ...
Co-cultivation of Thermoanaerobacter strains with a methanogenic partner enhanc...
Magalhães, Carla Isabel Pereira; Ribeiro, Joaquim Alfredo França Martins; Guedes, Ana P.; Arantes, Ana Luísa; Sousa, Diana Zita MachadoGlycerolrich waste streams produced by the biodiesel, bioethanol and oleochemical industries can be treated and valorized by anaerobic microbial communities to produce methane. As current knowledge of the microorganisms involved in thermophilic glycerol conversion to methane is scarce, thermophilic glyceroldegrading methanogenic communities were enriched. A coculture of Thermoanaerobacter and Methanothermobacte...
Effect of sub-stoichiometric Fe(III) amounts on LCFA degradation by methanogeni...
Cavaleiro, Ana Júlia; Guedes, Ana P.; Silva, Sérgio Alves; Arantes, Ana Luísa; Costa, João Carlos Sequeira; Salvador, Andreia Filipa FerreiraLong-chain fatty acids (LCFA) are common contaminants in municipal and industrial wastewater that can be converted anaerobically to methane. A low hydrogen partial pressure is required for LCFA degradation by anaerobic bacteria, requiring the establishment of syntrophic relationships with hydrogenotrophic methanogens. However, high LCFA loads can inhibit methanogens, hindering biodegradation. Because it has bee...
Inhibition studies with 2-bromoethanesulfonate reveal a novel syntrophic relati...
Salvador, Andreia F.; Cavaleiro, Ana Júlia; Paulo, Ana M. S.; Silva, Sérgio Alves; Guedes, Ana P.; Pereira, M. Alcina; Stams, Alfons Johannes MariaDegradation of long-chain fatty acids (LCFAs) in methanogenic environments is a syntrophic process involving the activity of LCFA-degrading bacteria and hydrogen-utilizing methanogens. If methanogens are inhibited, other hydrogen scavengers are needed to achieve complete LCFA degradation. In this work, we developed two different oleate (C18:1 LCFA)-degrading anaerobic enrichment cultures, one methanogenic (ME) ...
Exploring syntrophic relationships in the anaerobic biodegradation of lipids an...
Cavaleiro, Ana Júlia; Ribeiro, J.; Guedes, Ana P.; Pereira, Ana Luísa Arantes Carvalho; Pereira, M. A.; Sousa, Diana Zita Machado; Alves, M. M.[Excerpt] Practical knowledge on anaerobic digestion of waste lipids has been improving for several decades, but the microbiology of these processes remains partially undisclosed, with non-cultivated taxonomic groups often detected in anaerobic communities degrading lipids. This work studies the diversity and physiology of anaerobic microorganisms involved in the metabolism of lipids and long chain fatty acids....
Conversion of Cn-unsaturated into Cn-2-saturated LCFA can occur uncoupled from ...
Cavaleiro, A. J.; Pereira, M. A.; Guedes, Ana P.; Stams, Alfons Johannes Maria; Alves, M. M.; Sousa, Diana Zita MachadoFat, oils, and grease present in complex wastewater can be readily converted to methane, but the energy potential of these compounds is not always recyclable, due to incomplete degradation of long chain fatty acids (LCFA) released during lipids hydrolysis. Oleate (C18:1) is generally the dominant LCFA in lipid-containing wastewater, and its conversion in anaerobic bioreactors results in palmitate (C16:0) accumu...
Energy production from lipids by novel anaerobes
Cavaleiro, A. J.; Duarte, M. S.; Silva, Sérgio Alves; Salvador, A. F.; Guedes, Ana P.; Ribeiro, J. A.; Sousa, Diana Zita Machado; Pereira, M. A.[Excerpt] Anaerobic microbial diversity encloses a very high potential that can be used for biotechnological applications. This potential is still largely unexplored, since the majority of the microorganisms in Nature are unknown or poorly characterized. This work is focused on the study of novel anaerobic microorganisms that participate in the metabolism of lipids, long chain fatty acids (LCFA) and glycerol, w...
Effect of sulfate and iron (III) on LCFA degradation by a methanogenic community
Guedes, Ana P.; Cavaleiro, A. J.; Silva, Sérgio Alves; Alves, M. M.; Stams, Alfons Johannes Maria; Sousa, Diana Zita Machado[Excerpt] Under anaerobic conditions long chain fatty acids (LCFA) can be converted to methane by syntrophic bacteria and methanogenic archaea. LCFA degradation was also reported in the presence of alternative hydrogenotrophic partners, such as sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB), which generally show higher affinity for H2 than methanogens and are more resistant to LCFA [1,2,3]. Th...
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...
Growth of sulfate reducing bacteria on the methanogenic inhibitor BES
Salvador, A. F.; Cavaleiro, A. J.; Silva, Sérgio Alves; Guedes, Ana P.; Pereira, M. A.; Stams, Alfons Johannes Maria; Sousa, Diana Zita MachadoThe metabolism of methanogenic archaea is inhibited by 2-bromoethanesulfonate (BES). Methane production is blocked because BES is an analog of methyl-coenzyme M and competes with this key molecule in the last step of methanogenesis. For this reason, BES is commonly used in several studies to avoid growth of acetoclastic and hydrogenotrophic methanogens [1]. Despite its effectiveness as methanogenic inhibitor, B...