• Trace gas microbiogeochemistry laboratory "Observation, exploitation and protection of biogeochemical functions"
  • Trace gas microbiogeochemistry laboratory "Observation, exploitation and protection of biogeochemical functions"
  • Trace gas microbiogeochemistry laboratory "Observation, exploitation and protection of biogeochemical functions"
  • Trace gas microbiogeochemistry laboratory "Observation, exploitation and protection of biogeochemical functions"
  • Trace gas microbiogeochemistry laboratory "Observation, exploitation and protection of biogeochemical functions"
  • Trace gas microbiogeochemistry laboratory "Observation, exploitation and protection of biogeochemical functions"
Research
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Sampling site where Streptomyces sp. PCB7 - the first microorganisms demonstrating the ability to oxidize atmospheric H2 - was isolated. 

 

Soil uptake of atmospheric H2 — discovery of the missing link

The isolation of several Streptomyces demonstrating the ability to oxidize atmospheric H2 constitutes a major breakthrough in the field of H2 biochemistry. This discovery challenged a controversial concept in microbiology since the soil uptake of atmospheric H2 was previously attributed to the occurrence of free soil hydrogenases. Microcosms will be deployed in the laboratory to analyze the environmental control on the expression and activity of high affinity [NiFe]-hydrogenases. Critical environmental parameters influencing high affinity H2 oxidation activity will be indentified in controlled environments, allowing the establishment of conceptual models to be tested by strategic field investigations realized in contrasting ecosystems. Support from the Joint Genome Institute (Community Sequencing Program) allows us to use metagenomic and metatranscriptomic approaches to study the interactions between H2-oxidizing bacteria and the other microorganisms involved in nutrient cycling in soil.


Long-term objective: Predict the impact of global change on the budget of atmospheric H2.
Funding: NSERC-Discovery and Joint Genome Institute (Community Sequencing Program) 

 


 

 

 

CARD-FISH to visualize the expression of high affinity hydrogenase in the spores of Streptomyces sp. PCB7.

Image: Jennifer Pratscher.

 

 

Characterization of a hydrogenase demonstrating unusual properties


We are currently employing Streptomyces avermitilis as a model microorganism to shed light on the physiological role, regulation and biochemical properties of high affinity [NiFe]-hydrogenases. An inducible over-expression system is being developed, allowing us to undertake the first biochemical characterization of high affinity [NiFe]-hydrogenase. The purified recombinant hydrogenase will be challenged to evaluate the optimal conditions and the potential limitations for the operation of the biocatalyst - a mandatory step to assess the biotechnological application of high affinity hydrogenases.

Long-term objective: Improve the yield of secondary metabolites production, biodegradation and other bioprocesses with the energy generated by a recombinant high affinity hydrogenase.

Funding: NSERC-Discovery

 

 

 

◄ Arrangement of the auxiliary and structural genes of the putative high affinity [NiFe]-hydrogenase in S. avermitilis.

 


 

 

Liliana measuring the soil uptake of atmospheric CO.

Identification of the microorganisms responsible for the soil sink of atmospheric CO


A new research project initiated in 2012 allowed us to demonstrate that influence of land-use on the soil uptake of atmospheric CO is due to an alteration of CO-oxidizing bacterial community structure. We have identified putative groups responsible for the activity and a combination of genetics and microbiological approaches is currently used to validate how hypothesis. This work will lead to the development of new generation model to predict how the soil sink of atmospheric CO will respond to global change. A first article describing our findings was published in the journal "Frontiers in Terrestrial Microbiology" in a special issue dedicated to "the impact of microorganisms on consumption of atmospheric trace gases".

Funding: FRQNT-New Researcher Start-Up program