Altered bacterial metabolism, not coenzyme Q content, is responsible for the lifespan extension in Caenorhabditis elegans fed an Escherichia coli diet lacking coenzyme Q

Ryoichi Saiki, Adam L. Lunceford, Tarra Bixler, Peter Dang, Wendy Lee, Satoru Furukawa, Pamela L. Larsen, Catherine F. Clarke

Research output: Contribution to journalArticle

45 Scopus citations


Coenzyme Qn is a fully substituted benzoquinone containing a polyisoprene tail of distinct numbers (n) of isoprene groups. Caenorhabditis elegans fed Escherichia coli devoid of Q8 have a significant lifespan extension when compared to C. elegans fed a standard 'Q-replete' E. coli diet. Here we examine possible mechanisms for the lifespan extension caused by the Q-less E. coli diet. A bioassay for Q uptake shows that a water-soluble formulation of Q10 is effectively taken up by both clk-1 mutant and wild-type nematodes, but does not reverse lifespan extension mediated by the Q-less E. coli diet, indicating that lifespan extension is not due to the absence of dietary Q per se. The enhanced longevity mediated by the Q-less E. coli diet cannot be attributed to dietary restriction, different Qn isoforms, reduced pathogenesis or slowed growth of the Q-less E. coli, and in fact requires E. coli viability. Q-less E. coli have defects in respiratory metabolism. C. elegans fed Q-replete E. coli mutants with similarly impaired respiratory metabolism due to defects in complex V also show a pronounced lifespan extension, although not as dramatic as those fed the respiratory deficient Q-less E. coli diet. The data suggest that feeding respiratory incompetent E. coli, whether Q-less or Q-replete, produces a robust life extension in wild-type C. elegans. We believe that the fermentation-based metabolism of the E. coli diet is an important parameter of C. elegans longevity.

Original languageEnglish (US)
Pages (from-to)291-304
Number of pages14
JournalAging cell
Issue number3
StatePublished - Jun 1 2008



  • Aging
  • Caenorhabditis elegans
  • Coenzyme Q or ubiquinone
  • clk-1
  • dietaryrestriction
  • respiratorydefective Escherichia coli

ASJC Scopus subject areas

  • Aging
  • Cell Biology

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