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Syntrophic LCFA-degraders: “bacteria that can clean soap”

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Detalhes bibliográficos
Resumo:Wastewaters contain substantial amounts of long-chain fatty acids (LCFA) which, when in the form of sodium salts, are what we normally call soaps. These compounds, resulting from fats' hydrolysis, can be converted to high amounts of methane. Developing new technological solutions for LCFA methanation, but also understanding the physiology and microbiology of LCFA degradation is fundamental for the bioenergy valorization of fatty wastewaters. In this work we present an overview of our results on anaerobic LCFA microbial degradation. Molecular techniques were used to investigate the structure of microbial communities present in different LCFA-degrading communities, such as continuous oleate- and palmitate-fed bioreactors and several enrichment cultures degrading these two LCFA as well. Choice of oleate and palmitate as model substrates was due to their predominance in wastewaters and to the fact that they represent mono-unsaturated and saturated LCFA, respectively. DGGE fingerprinting and sequencing evidenced the importance of syntrophic bacteria, affiliated with the Syntrophomonas genus, in the degradation of these compounds. Enrichment on oleate or palmitate resulted in distinct bacterial communities, which might be related to LCFA chain-saturation differences. A new obligately syntrophic bacterium, Syntrophomonas zehnderi, was isolated from an oleate-degrading culture. The fact that S. zehnderi can degrade a wide range of fatty-acids with different chain length (C4-C18) and is also able to use unsaturated LCFA (e.g. oleate) makes it a destined and dedicated key for the anaerobic treatment of wastewaters, in which an assembly of different fatty-acids is normally present. Genome sequencing of S. zehnderi is currently undergoing.
Autores principais:Sousa, D. Z.
Outros Autores:Smidt, Hauke; Stams, Alfons Johannes Maria; Alves, M. M.
Ano:2008
País:Portugal
Tipo de documento:outro
Tipo de acesso:acesso aberto
Instituição associada:Universidade do Minho
Idioma:inglês
Origem:RepositóriUM - Universidade do Minho
Descrição
Resumo:Wastewaters contain substantial amounts of long-chain fatty acids (LCFA) which, when in the form of sodium salts, are what we normally call soaps. These compounds, resulting from fats' hydrolysis, can be converted to high amounts of methane. Developing new technological solutions for LCFA methanation, but also understanding the physiology and microbiology of LCFA degradation is fundamental for the bioenergy valorization of fatty wastewaters. In this work we present an overview of our results on anaerobic LCFA microbial degradation. Molecular techniques were used to investigate the structure of microbial communities present in different LCFA-degrading communities, such as continuous oleate- and palmitate-fed bioreactors and several enrichment cultures degrading these two LCFA as well. Choice of oleate and palmitate as model substrates was due to their predominance in wastewaters and to the fact that they represent mono-unsaturated and saturated LCFA, respectively. DGGE fingerprinting and sequencing evidenced the importance of syntrophic bacteria, affiliated with the Syntrophomonas genus, in the degradation of these compounds. Enrichment on oleate or palmitate resulted in distinct bacterial communities, which might be related to LCFA chain-saturation differences. A new obligately syntrophic bacterium, Syntrophomonas zehnderi, was isolated from an oleate-degrading culture. The fact that S. zehnderi can degrade a wide range of fatty-acids with different chain length (C4-C18) and is also able to use unsaturated LCFA (e.g. oleate) makes it a destined and dedicated key for the anaerobic treatment of wastewaters, in which an assembly of different fatty-acids is normally present. Genome sequencing of S. zehnderi is currently undergoing.