title: Effect of prolonged hypoxia in autotrophic conditions in the hydrogen production by the green microalga Chlamydomonas reinhardtii in photobioreactor.
abstract: In the context of hydrogen production by the green alga Chlamydomonas reinhardtii, the control of light attenuation conditions is used to set-up anoxia under illuminated and autotrophic conditions, without affecting photosynthetic capacities of cells (as with sulphur deprivation or PSII inhibitors like DCMU). This paper presents a full description of the protocol where the incident photons flux density (PFD) is adapted during cultivation in order to obtain a sufficiently low illuminated fraction γ under 0.25 leading to anoxic hydrogen producing conditions during several days. The protocol is validated in a torus-shape photobioreactor (PBR) revealing after few days of anoxic conditions a peak of hydrogen production (1.44 ml H2/h/l of culture; [0.8-1.0] ml H2/h/g of dry weight biomass) concomitant with a decrease of biomass concentration, protein content and maximal photosynthetic yield. Effect of over-accumulating starch, as being known to increase hydrogen production by the PSII-independent pathway, is also investigated.
authors.affiliation: Université de Nantes, CNRS, GEPEA UMR-CNRS 6144, Bd de l'Université, CRTT-BP 406, 44602 Saint-Nazaire Cedex, France.
authors.forename: B
authors.initials: B
authors.lastname: Degrenne
authors.forename: J
authors.initials: J
authors.lastname: Pruvost
authors.forename: J
authors.initials: J
authors.lastname: Legrand
mesh_terms: D000693:Anaerobiosis; D052818:Autotrophic Processes; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D058086:Microalgae / Q000378:metabolism*; D058433:Photobioreactors / Q000382:microbiology*; D017785:Photons; D015203:Reproducibility of Results; D013213:Starch / Q000378:metabolism; D013997:Time Factors
chemical_list: D006859:Hydrogen; D013213:Starch