title: Functional integration of the HUP1 hexose symporter gene into the genome of C. reinhardtii: Impacts on biological H(2) production.
abstract: Phototrophic organisms use photosynthesis to convert solar energy into chemical energy. In nature, the chemical energy is stored in a diverse range of biopolymers. These sunlight-derived, energy-rich biopolymers can be converted into environmentally clean and CO(2) neutral fuels. A select group of photosynthetic microorganisms have developed the ability to extract and divert protons and electrons derived from water to chloroplast hydrogenase(s) to produce molecular H(2) fuel. Here, we describe the development and characterization of C. reinhardtii strains, derived from the high H(2) production mutant Stm6, into which the HUP1 (hexose uptake protein) hexose symporter from Chlorella kessleri was introduced. The isolated cell lines can use externally supplied glucose for heterotrophic growth in the dark. More importantly, external glucose supply (1mM) was shown to increase the H(2) production capacity in strain Stm6Glc4 to approximately 150% of that of the high-H(2) producing strain, Stm6. This establishes the foundations for a new fuel production process in which H(2)O and glucose can simultaneously be used for H(2) production. It also opens new perspectives on future strategies for improving bio-H(2) production efficiency under natural day/night regimes and for using sugar waste material for energy production in green algae as photosynthetic catalysts.
authors.affiliation: Department of Biology, Algae Biotech Group, University Bielefeld, Bielefeld, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Doebbe
authors.forename: Jens
authors.initials: J
authors.lastname: Rupprecht
authors.forename: Julia
authors.initials: J
authors.lastname: Beckmann
authors.forename: Jan H
authors.initials: JH
authors.lastname: Mussgnug
authors.forename: Armin
authors.initials: A
authors.lastname: Hallmann
authors.forename: Ben
authors.initials: B
authors.lastname: Hankamer
authors.forename: Olaf
authors.initials: O
authors.lastname: Kruse
mesh_terms: D000818:Animals; D050260:Carbohydrate Metabolism / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D016825:Chlamydomonas reinhardtii / Q000166:cytology / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D003624:Darkness; D005822:Genetic Vectors; D018503:Genome, Protozoan / Q000235:genetics*; D005947:Glucose / Q000494:pharmacology; D052836:Heterotrophic Processes / Q000187:drug effects; D006859:Hydrogen / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000235:genetics*; D027981:Symporters / Q000235:genetics*; D014170:Transformation, Genetic / Q000187:drug effects
chemical_list: D009004:Monosaccharide Transport Proteins; D027981:Symporters; D006859:Hydrogen; D005947:Glucose