title: Investigation and modeling of biomass decay rate in the dark and its potential influence on net productivity of solar photobioreactors for microalga Chlamydomonas reinhardtii and cyanobacterium Arthrospira platensis.
abstract: Biomass decay rate (BDR) in the dark was investigated for Chlamydomonas reinhardtii (microalga) and Arthrospira platensis (cyanobacterium). A specific setup based on a torus photobioreactor with online gas analysis was validated, enabling us to follow the time course of the specific BDR using oxygen monitoring and mass balance. Various operating parameters that could limit respiration rates, such as culture temperature and oxygen deprivation, were then investigated. C. reinhardtii was found to present a higher BDR in the dark than A. platensis, illustrating here the difference between eukaryotic and prokaryotic cells. In both cases, temperature proved an influential parameter, and the Arrhenius law was found to efficiently relate specific BDR to culture temperature. The utility of decreasing temperature at night to increase biomass productivity in a solar photobioreactor is also illustrated.
authors.affiliation: Université de Nantes, CNRS, GEPEA UMR-CNRS 6144, boulevard de l'Université, CRTT-BP 406, 44602 Saint-Nazaire Cedex, France. francois.leborgne@algosource.com
authors.forename: François
authors.initials: F
authors.lastname: Le Borgne
authors.forename: Jérémy
authors.initials: J
authors.lastname: Pruvost
mesh_terms: D018533:Biomass; D016825:Chlamydomonas reinhardtii / Q000378:metabolism* / Q000528:radiation effects; D000458:Cyanobacteria / Q000378:metabolism* / Q000528:radiation effects; D058086:Microalgae / Q000378:metabolism* / Q000528:radiation effects; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism; D058433:Photobioreactors / Q000382:microbiology*; D013472:Sunlight; D013696:Temperature; D013997:Time Factors
chemical_list: D010100:Oxygen