Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/27460

TitleActivity and viability of methanogens in anaerobic digestion of unsaturated and saturated long-chain fatty acids
Author(s)Sousa, D. Z.
Salvador, Andreia Filipa Ferreira
Ramos, Juliana
Guedes, Ana P.
Barbosa, Sónia
Stams, Alfons Johannes Maria
Alves, M. M.
Pereira, M. A.
Issue dateJul-2013
PublisherAmerican Society for Microbiology (ASM)
JournalApplied and Environmental Microbiology
Abstract(s)Lipids can be anaerobically digested to methane, but methanogens are often considered to be highly sensitive to the long-chain fatty acids (LCFA) deriving from lipids hydrolysis. In this study, the effect of unsaturated (oleate [C18:1]) and saturated (stearate [C18:0] and palmitate [C16:0]) LCFA toward methanogenic archaea was studied in batch enrichments and in pure cultures. Overall, oleate had a more stringent effect on methanogens than saturated LCFA, and the degree of tolerance to LCFA was different among distinct species of methanogens. Methanobacterium formicicum was able to grow in both oleate- and palmitate-degrading enrichments (OM and PM cultures, respectively), whereas Methanospirillum hungatei only survived in a PMculture. The two acetoclastic methanogens tested, Methanosarcina mazei and Methanosaeta concilii, could be detected in both enrichment cultures, with better survival in PM cultures than inOMcultures. Viability tests using live/dead staining further confirmed that exponential growth-phase cultures of M. hungatei are more sensitive to oleate than are M. formicicum cultures; exposure to 0.5 mMoleate damaged 99% 1% of the cell membranes of M. hungatei and 53% 10% of the cell membranes of M. formicicum. In terms of methanogenic activity, M. hungatei was inhibited for 50% by 0.3, 0.4, and 1mMoleate, stearate, and palmitate, respectively. M. formicicum was more resilient, since 1mMoleate and>4mMstearate or palmitate was needed to cause 50% inhibition on methanogenic activity.
TypeArticle
URIhttp://hdl.handle.net/1822/27460
DOI10.1128/AEM.00035-13
ISSN0099-2240
e-ISSN1098-5336
Peer-Reviewedyes
AccessRestricted access (UMinho)
Appears in Collections:CEB - Publicações em Revistas/Séries Internacionais / Publications in International Journals/Series

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