Methanogenesis from acetate and propionate by thermophilic down-flow anaerobic packed-bed reactor

Tatara, Masahiro; Makiuchi, Takashi; Ueno, Yoshiyuki; Goto, Masafumi; Sode, Koji

doi:10.1016/j.biortech.2007.09.069

Cited by 71 publications

(28 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Recently, several culture-independent molecular studies have indicated that microbes which are phylogenetically related to previously isolated syntrophic acetate-oxidizing bacteria are present in some environments including methanogenic reactors [70][71][72][73] , leachate 24) , and an oil reservoir 44) . Also, applications of a functional gene for formyl-THF synthetase implied the presence of phylogenetically diverse acetogens in several natural habitats 34,35,46,48,49,54) .…”

Section: Discussionmentioning

confidence: 99%

Syntrophic Acetate-Oxidizing Microbes in Methanogenic Environments

2008

View full text Add to dashboard Cite

Acetate is one of the most important intermediates for methanogenesis in the anaerobic mineralization of organic materials. Methanogenic acetate degradation is carried out by either an aceticlastic reaction or an anaerobic acetateoxidizing reaction. In contrast to the former reaction, the latter is energetically extremely unfavorable. However, the oxidation of acetate can occur with syntrophic interaction between certain bacteria and methanogenic archaea. The bacteria, namely syntrophic acetate-oxidizing bacteria, can oxidize acetate to produce hydrogen/CO2 only when their products are subsequently utilized by the hydrogen-scavenging methanogens. Surprisingly, some of these bacteria can also axenically grow on hydrogen/CO2 to produce acetate. This means that the bacteria can utilize both substrates and products reversibly. This review describes current studies of these curious and fascinating microbes.

show abstract

Section: Discussionmentioning

confidence: 99%

Syntrophic Acetate-Oxidizing Microbes in Methanogenic Environments

2008

View full text Add to dashboard Cite

show abstract

“…One of the materials that has shown promise is carbon cloth (Sasaki et al, 2007(Sasaki et al, , 2009(Sasaki et al, , 2010Tatara et al, 2008;Zhang et al, 2012;Zhao et al, 2013). In these studies the enhanced methane production in the presence of carbon cloth was attributed to its ability to promote microbial attachment.…”

Section: Introductionmentioning

confidence: 99%

“…This study aimed to reveal if carbon cloth, often used in rector design, presumably because of its biomass retention properties (Sasaki et al, 2007(Sasaki et al, , 2009(Sasaki et al, , 2010Tatara et al, 2008;Zhang et al, 2012;Zhao et al, 2013) would rather serve as an electrical conduit to promote DIET. As control we tested non-conductive cotton cloth with similar biomass retention properties.…”

Section: Introductionmentioning

confidence: 99%

Carbon cloth stimulates direct interspecies electron transfer in syntrophic co-cultures

Chen

Rotaru

Liu

et al. 2014

Bioresource Technology

346

150

View full text Add to dashboard Cite

h i g h l i g h t sConductive carbon cloth stimulated syntrophic metabolism in DIET co-cultures. Carbon cloth did not stimulate metabolism in a co-culture that relied on H 2 transfer. Non-conductive cotton cloth did not facilitate DIET. Carbon cloth restored DIET in Geobacter strains missing pili or OmcS cytochrome. a r t i c l e i n f o t r a c tThis study investigated the possibility that the electrical conductivity of carbon cloth accelerates direct interspecies electron transfer (DIET) in co-cultures. Carbon cloth accelerated metabolism of DIET co-cultures (Geobacter metallireducens-Geobacter sulfurreducens and G. metallireducens-Methanosarcina barkeri) but did not promote metabolism of co-cultures performing interspecies H 2 transfer (Desulfovibrio vulgaris-G. sulfurreducens). On the other hand, DIET co-cultures were not stimulated by poorly conductive cotton cloth. Mutant strains lacking electrically conductive pili, or pili-associated cytochromes participated in DIET only in the presence of carbon cloth. In co-cultures promoted by carbon cloth, cells were primarily associated with the cloth although the syntrophic partners were too far apart for cell-to-cell biological electrical connections to be feasible. Carbon cloth seemingly mediated interspecies electron transfer between the distant syntrophic partners. These results suggest that the ability of carbon cloth to accelerate DIET should be considered in anaerobic digester designs that incorporate carbon cloth.

show abstract

“…Similar to biochar and activated carbon, carbon fibers have been used as a supporting medium for bacterial growth in bioreactors. Biofilms can easily form on the surfaces of carbon fibers and help in increasing biomass retention time inside the reactors, resulting in improved AD performance [71,72]. However, recent studies have suggested the possibility of using carbon fibers as DIET promoters.…”

Section: Carbon Fibersmentioning

confidence: 99%

Role and Potential of Direct Interspecies Electron Transfer in Anaerobic Digestion

et al. 2018

View full text Add to dashboard Cite

Anaerobic digestion (AD) is an effective biological treatment for stabilizing organic compounds in waste/wastewater and in simultaneously producing biogas. However, it is often limited by the slow reaction rates of different microorganisms' syntrophic biological metabolisms. Stable and fast interspecies electron transfer (IET) between volatile fatty acid-oxidizing bacteria and hydrogenotrophic methanogens is crucial for efficient methanogenesis. In this syntrophic interaction, electrons are exchanged via redox mediators such as hydrogen and formate. Recently, direct IET (DIET) has been revealed as an important IET route for AD. Microorganisms undergoing DIET form interspecies electrical connections via membrane-associated cytochromes and conductive pili; thus, redox mediators are not required for electron exchange. This indicates that DIET is more thermodynamically favorable than indirect IET. Recent studies have shown that conductive materials (e.g., iron oxides, activated carbon, biochar, and carbon fibers) can mediate direct electrical connections for DIET. Microorganisms attach to conductive materials' surfaces or vice versa according to particle size, and form conductive biofilms or aggregates. Different conductive materials promote DIET and improve AD performance in digesters treating different feedstocks, potentially suggesting a new approach to enhancing AD performance. This review discusses the role and potential of DIET in methanogenic systems, especially with conductive materials for promoting DIET.

show abstract

Methanogenesis from acetate and propionate by thermophilic down-flow anaerobic packed-bed reactor

Cited by 71 publications

References 29 publications

Syntrophic Acetate-Oxidizing Microbes in Methanogenic Environments

Syntrophic Acetate-Oxidizing Microbes in Methanogenic Environments

Carbon cloth stimulates direct interspecies electron transfer in syntrophic co-cultures

Role and Potential of Direct Interspecies Electron Transfer in Anaerobic Digestion

Contact Info

Product

Resources

About