title: Cooperative growth of Geobacter sulfurreducens and Clostridium pasteurianum with subsequent metabolic shift in glycerol fermentation.
abstract: Interspecies electron transfer is a common way to couple metabolic energy balances between different species in mixed culture consortia. Direct interspecies electron transfer (DIET) mechanism has been recently characterised with Geobacter species which couple the electron balance with other species through physical contacts. Using this mechanism could be an efficient and cost-effective way to directly control redox balances in co-culture fermentation. The present study deals with a co-culture of Geobacter sulfurreducens and Clostridium pasteurianum during glycerol fermentation. As a result, it was shown that Geobacter sulfurreducens was able to grow using Clostridium pasteurianum as sole electron acceptor. C. pasteurianum metabolic pattern was significantly altered towards improved 1,3-propanediol and butyrate production (+37% and +38% resp.) at the expense of butanol and ethanol production (-16% and -20% resp.). This metabolic shift was clearly induced by a small electron uptake that represented less than 0.6% of the electrons consumed by C. pasteurianum. A non-linear relationship was found between G. sulfurreducens growth (i.e the electrons transferred between the two species) and the changes in C. pasteurianum metabolite distribution. This study opens up new possibilities for controlling and increasing specificity in mixed culture fermentation.
authors.affiliation: LBE, INRA, 102 Avenue des étangs, 11100 Narbonne, France.
authors.forename: Roman
authors.initials: R
authors.lastname: Moscoviz
authors.affiliation: LBE, INRA, 102 Avenue des étangs, 11100 Narbonne, France.
authors.forename: Florence
authors.initials: F
authors.lastname: de Fouchécour
authors.affiliation: LBE, INRA, 102 Avenue des étangs, 11100 Narbonne, France.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Santa-Catalina
authors.affiliation: LBE, INRA, 102 Avenue des étangs, 11100 Narbonne, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bernet
authors.affiliation: LBE, INRA, 102 Avenue des étangs, 11100 Narbonne, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Trably
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods; D002087:Butyrates / Q000378:metabolism; D003013:Clostridium / Q000254:growth & development / Q000378:metabolism*; D004579:Electron Transport; D005285:Fermentation; D045302:Geobacter / Q000254:growth & development / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism*; D056265:Microbial Interactions; D011409:Propylene Glycols / Q000378:metabolism
chemical_list: D002087:Butyrates; D011409:Propylene Glycols; C041787:1,3-propanediol; D005990:Glycerol