Hydrogen production in algal-bacterial cultures Dr. Gergely Ernő Lakatos 2016.10.27.

Stress induced algal hydorgen production methodes Stress induced algal hydrogen production methodes under illumination: Sulfur Nitrogen Phosphate Magnesium DEPRIVATION Disadvantages: Separated biomass and hydrogen production OR Precise addition of the deprived nutrient Slow hydrogen production initiation (1-8 days) Inhibited biomass growth

Setup of algal-bacterial hydrogen producing system Tris-Acetate-Phosphate media Carbon source: acetic acid. O2 CO2

Obtained results Establishing pure algal and bacterial cultures from infected algal cultures Determination of the algal and bacterial strains Algae: Chlamydomonas Chlorella Scenedesmus Bacteria: Wilde types (detected in the algae culture): Rhodcoccus sp. Brevundimonas sp. Leifsonia sp.

Obtained results Advantges: Mixed biomass production during hydrogen evolution Elevated algal biomass production by the addition of bacterial partner Cooperation: biogas production by the produced algal-bacterial biomass Fast oxygen consumption by the bacterial partner Fast initiation of hydrogen production in 1-4 hours Disadvantages: Short hydrogen production time length Low hydrogen ptoduction rates

Obtained results Elevation of hydrogen production rate by: the application of hydrogenase defficient bacterial partner Artificially added strains (wild and hydrogenase defficient): Esherichia coli Ralstonia eutropha the optimization of gas-to-liquid phase ratios the optimization of culture optical density the reduction of algal cell size Optimized hydrogen production for daily harvesting (~100 ml H2 L-1 culture day-1), comperable hydrogen yield with sulfur-deprived results

Short term aim Establishing a semi-continuous hydrogen and biomass producing system in small scale (40 ml). Hydrogen release by purging of the headspace 1 day H2 H2 ambient air H2 H2 H2 low biomass content high biomass content acetic acid addition 40 mL sealed bottles Biomass harvesting

Long term aim 1. Finding cheap carbon source: using carbon dioxide as a sole carbon source. Hydrogen release by air purging 1 day H2 H2 ambient air H2 H2 H2 low biomass content high biomass content CO2 addition 40 mL sealed bottles Biomass harvesting

Long term aim 2. Finding cheap carbon source: using diluted biogas sludge supernatant as a media for biomass and hydrogen production. biogas production biomass fermentation filtration biomass production hydrogen production dilution algae addition

Thank you for your attention Email: lakatos.gergely@brc.mta.hu