Sustainable syntrophic growth of Dehalococcoides ethenogenes strain 195 with Desulfovibrio vulgaris Hildenborough and Methanobacterium congolense: global transcriptomic and proteomic analyses

ISME J. 2012 Feb;6(2):410-21. doi: 10.1038/ismej.2011.111. Epub 2011 Sep 1.

Abstract

Dehalococcoides ethenogenes strain 195 (DE195) was grown in a sustainable syntrophic association with Desulfovibrio vulgaris Hildenborough (DVH) as a co-culture, as well as with DVH and the hydrogenotrophic methanogen Methanobacterium congolense (MC) as a tri-culture using lactate as the sole energy and carbon source. In the co- and tri-cultures, maximum dechlorination rates of DE195 were enhanced by approximately three times (11.0±0.01 μmol per day for the co-culture and 10.1±0.3 μmol per day for the tri-culture) compared with DE195 grown alone (3.8±0.1 μmol per day). Cell yield of DE195 was enhanced in the co-culture (9.0±0.5 × 10(7) cells per μmol Cl(-) released, compared with 6.8±0.9 × 10(7) cells per μmol Cl(-) released for the pure culture), whereas no further enhancement was observed in the tri-culture (7.3±1.8 × 10(7) cells per μmol Cl(-) released). The transcriptome of DE195 grown in the co-culture was analyzed using a whole-genome microarray targeting DE195, which detected 102 significantly up- or down-regulated genes compared with DE195 grown in isolation, whereas no significant transcriptomic difference was observed between co- and tri-cultures. Proteomic analysis showed that 120 proteins were differentially expressed in the co-culture compared with DE195 grown in isolation. Physiological, transcriptomic and proteomic results indicate that the robust growth of DE195 in co- and tri-cultures is because of the advantages associated with the capabilities of DVH to ferment lactate to provide H(2) and acetate for growth, along with potential benefits from proton translocation, cobalamin-salvaging and amino acid biosynthesis, whereas MC in the tri-culture provided no significant additional benefits beyond those of DVH.

MeSH terms

  • Animals
  • Chloroflexi / genetics
  • Chloroflexi / growth & development
  • Chloroflexi / metabolism
  • Chloroflexi / physiology*
  • Coculture Techniques
  • Desulfovibrio vulgaris / genetics
  • Desulfovibrio vulgaris / growth & development
  • Desulfovibrio vulgaris / metabolism
  • Desulfovibrio vulgaris / physiology*
  • Gene Expression Profiling
  • Gene Expression Regulation, Bacterial
  • Lactates / metabolism
  • Methanobacterium / genetics
  • Methanobacterium / metabolism
  • Methanobacterium / physiology*
  • Proteomics*
  • Stress, Physiological
  • Transcriptome*

Substances

  • Lactates