Coexistence of two distinct Sulfurospirillum populations respiring tetrachloroethene - genomic and kinetic considerations

Géraldine Florence Buttet, Alexandra Marie Murray, Tobias Goris, Mélissa Burion, Biao Jin, Massimo Rolle, Christof Holliger, Julien Maillard*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

232 Downloads (Pure)

Abstract

Two anaerobic bacterial consortia, each harboring a distinct Sulfurospirillum population, were derived from a ten year old consortium, SL2, previously characterized for the stepwise dechlorination of tetrachloroethene (PCE) to cis-dichloroethene (cis-DCE) via accumulation of trichloroethene (TCE). Population SL2-1 dechlorinated PCE to TCE exclusively, while SL2-2 produced cis-DCE from PCE without substantial TCE accumulation. The reasons explaining the long-term coexistence of the populations were investigated. Genome sequencing revealed a novel Sulfurospirillum species, designated 'Candidatus Sulfurospirillum diekertiae', whose genome differed significantly from other Sulfurospirillum spp. (78-83% ANI). Genome-wise, SL2-1 and SL2-2 populations are almost identical, but differences in their tetrachloroethene reductive dehalogenase sequences explain the distinct dechlorination patterns. An extended series of batch cultures were performed at PCE concentrations of 2-200 μM. A model was developed to determine their dechlorination kinetic parameters. The affinity constant and maximal growth rate differ between the populations: the affinity is 6- to 8-fold higher and the growth rate 5-fold lower for SL2-2 than SL2-1. Mixed cultivation of the enriched populations at 6 and 30 μM PCE showed that a low PCE concentration could be the driving force for both functional diversity of reductive dehalogenases and niche specialization of organohalide-respiring bacteria with overlapping substrate ranges.
Original languageEnglish
Article numberfiy018
JournalFEMS Microbiology Ecology
Volume94
Issue number5
Number of pages18
ISSN0168-6496
DOIs
Publication statusPublished - 2018

Keywords

  • Organohalide respiration
  • Sulfurospirillum
  • Reductive Dehalogenase
  • Tetrachloroethene
  • Kinetics
  • Numerical modeling

Fingerprint

Dive into the research topics of 'Coexistence of two distinct Sulfurospirillum populations respiring tetrachloroethene - genomic and kinetic considerations'. Together they form a unique fingerprint.

Cite this