Bioethanol from microalgae

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Miguel G. Guerrero del Instituto de Bioqiímica Vegetal y Fotosíntesis de la Universidad de Sevilla-CSIC, presenta el mercado de producción de Bioethanol de microalgas y las ventajas de usar microalgas a la hora de producir BIoethanol. 8_04_2010

Text of Bioethanol from microalgae

  • 1.Bioethanol from microalgae?Miguel G. GuerreroInstituto de Bioqumica Vegetal y Fotosntesis Universidad de SevillaConsejo Superior de Investigaciones CientficasSevilla, Spain

2. Total EU27 biodiesel production for 2008 was over 7.7 Mton (~8,600ML)EEB: European Biodiesel Board 3. World ethanol production eBIO: European Bioethanol Fuel Associations 4. EU Ethanol production (ML) EU MEMBER STATE 2008 20072006 2005 2004Austria 8915 Belgium 51 Czech Republic7633 15 Finland 50133 France 950 539293144101 Germany581 394431165 25 Hungary15030 34 35Total imports of Ireland 10 7 bioethanol in EU: Italy 60601288 1900 ML in 2008 Latvia1518 12 12 12 Lithuania 2120 188 Netherlands914 158 14 Poland 200 155120 64 48 Slovakia9430 Spain346 348402303254 Sweden78 120140153 71 eBIO: European Bioethanol UK7520Fuel Associations TOTAL 28551803 1608913528 5. Raw materials for ethanol production in Europe (2008)eBIO: European Bioethanol Fuel Associations 6. MicroalgaEukaryotic microalgae and prokaryotic cyanobacteria are the major representatives of oxygen-evolving photosyntheticmicroorganisms COLLECTIVELYREFERRED TO ASMICROALGAE U.S. Department of Energy Genome Programs 7. Claimed advantages of microalgae overcrop plants for biofuel production Faster growth Higher productivity Use saline, brackish, waste water Do not compete with food/feed agriculture Can have very high carbohydrate/oil content Lower water consumption? Lower costs of production/processing? 8. Ethanol yields for various crops CROP PRODUCTIVITY (liters per hectare) Wheat2,500Corn 3,500Sugar beet 6,000Microalgae (projection) 20,000 9. Products from microalgae BiomassPigments (phycobiliproteins, carotenoids)Essential fatty acids (long-chain PUFAs)Bioactive compounds (diverse chemical nature and biological activity)ExopolysaccharidesMajor cell components (triglycerides, starch, glycogen) as feedstock for biofuels (biodiesel, bioethanol)Simple molecules with high energy contentAmmoniaHydrogenAlcoholsFatty acids 10. Biofuel generation from CO2 Through photosynthesis, at the expense of sunlight energy, energy-richcompounds are synthesized from oxidized, low energy substrates. The generation of an organic fuel entails besides CO2 removal CARBOHYDRATESALCOHOLSH2LIPIDS -0.4 VFdHYDROCARBONSH+ CO2 e +0.8 V H2OTHYLAKOIDS O2LIGHT 11. Choosing the microalga for producing bioethanols feedstock Factors to be considered in the selectionGrowth rate (); productivity (P= Cb)Selective advantages: tolerance to temperature, pH, and radiation extremes; secretion of allelopatic metabolites; ability to fix N2High yield in fermentable carbohydrates (starch, glycogen, EPS?)Easy (cheap) harvesting 12. Microalgae as potential source ofcarbohydrates Strain of Chlorella Carbohydrates (% of dry weight) +N -N C. ellipsoidea SK15,021,0 C. pyrenoidosa 8224,037,3 C. pyrenoidosa 82T 31,867,9 C. pyrenoidosaTKh-7-11-05 10,044,2 C. sp. K 18,454,5 C. vulgaris 15710,344,0Data from Vladimirova et al (1979) & Zhukova et al (1969) in Soviet Plant Physiology 13. Cyanobacteria as potential source ofcarbohydrates (Vargas et al. 1998, J. Phycol. 34, 812)Strain Carbohydrates (% of dry weight)________________________________________________Anabaena sp. ATCC 3304728.0 2.0Anabaena variabilis22.3 2.5Anabaenopsis sp. 16.3 1.5Nodularia sp. (Chucula)16.9 2.6Nostoc commune 37.6 2.5Nostoc paludosum 26.6 1.9Nostoc sp. (Albufera)26.8 4.0Nostoc sp. (Caquena) 23.3 1.7Nostoc sp. (Chile) 23.3 2.0Nostoc sp. (Chucula) 15.7 1.8Nostoc sp. (Llaita)20.2 1.5Nostoc sp. (Loa) 32.1 1.2 14. Marine strain of Anabaena (ATCC 33047, CA) High rate of CO2 fixation into organicmatterHigh productivityNo requirement for combined N (N2-fixer)Easy harvestingWide tolerance to: temperature (optimum 40C; 30-45) pH (optimum 8.5; 6.5-9.5) irradiance saltCarbohydrate content: 23-34% of dry biomass in actively growing cultures 15. Simultaneous to growth and biomass increase, Anabaena sp. ATCC 33047 releases to the medium substantial amounts of an exopolysaccharide (EPS) The EPS exhibits interesting rheological properties, and contributes to easy harvesting of biomass The EPS can find different applications, including fermentation 16. Anabaena cultures outdoorsPRODUCTIVITY0.050.6 g organic matter (biomass+EPS) L-1 d-1equivalent to 0.11.0 g CO2 fixed L-1 d-1YIELD OF FLAT PANEL REACTOR 0.1 (winter) to 0.35 (summer) g biomass L-1 d-1= ~35 g biomass m-2 d-1(8-11 g carbohydrates m-2 d-1) 17. ELECTRICITY POWER PLANT POWER PLANTFLUE FOSSIL FUEL FOSSIL FUEL(combustion)(combustion)PURIFICATIONPURIFICATIONCO2-RICH GAS GASES SUNLIGHT SUNLIGHT HEAT PHOTOBIOREACTORPHOTOBIOREACTOR(INOCULATED CULTURE)(INOCULATED CULTURE) BIOMASS BIOMASS DIVERSE OTHER ORGANIC COMPOUNDS OTHER ORGANIC COMPOUNDS APPLICATIONS 18. Establishing a production process for microalgaeas source of bioethanols feedstockFactors to be considered (and optimized) Organism - natural isolate (production site) - strain from culture collection - carbohydrate overproducing mutant (?) Culture system - open, closed, semi? Operating conditions- batch, semi-continuous, continuous?- nutrient limitation(s)?- one-stage, two-stage? 19. A plausible (although ambitious) objective, considering present state of art (highinsolation area) Reactors of ~50 L m-2 operating at mean volumetric productivity of ~0.7 g biomass L-1 day-1 (or of 140 L m-2 at 0.25 g L-1 day-1). Productivity = 35 g biomass m-2 day-1 For a carbohydrate content of ~30% = 10.5 g carbohydrate m-2 day-1 Surface extrapolation = 0.35 ton biomass (0.105 ton carbohydrate) ha-1 day-1 Surface + time extrapolation (effective operation 300 days per annum) =105 ton biomass (31.5 ton carbohydrate) ha-1 year-1 ~(19,000 L ethanol) ha-1 year-1 20. Microalgal metabolic pathways that can be leveraged for biofuel productionRadakovits et al. (2010) Eukaryotic Cell 9: 486-501 21. Starch metabolism in green microalgae Radakovits et al. (2010) Eukaryotic Cell 9:486-501 22. Fermentative production of bioethanol Raw materials Sugar cane (Brazil) Corn (USA) Wheat, corn, sugar beet (Europe) Alternatives: lignocellulosic materials; microalgaeCO2 emissionsAlcoholic fermentation (yeasts)C6H12O62 CH3CH2OH + 2 CO2(16 kJ g-1) (30 kJ g-1) 23. Ethanol photoproduction from CO2 LIGHT 2 CO2 + 3 H2O CH3CH2OH + 3 O2CO2 fixationEthanol photosynthesis CO2Calvincycle 3-PGAPYRUVATE ACETALDEHYDE ETHANOL PDC ADH 24. Synechocystis sp. PCC6803 (Sectionn I , Rippka et al., 1979) Fast growth Easy culture Model cyanobacterium Growth on glucose Full genomic sequence available ( Transformable (chromosome and plamid) Homologous recombination 25. Strategy for obtaining Synechocystis strains able to synthesizeethanol1. Insertion in Synechocystis genome of Zymomonas genes involved in ethanolsynthesis through homologous recombinationPpdc-adh Secuence homologous toSynechocystis DNA (needed for reombination) P Endogenous promotor (externally inducible) Pyruvate decarboxylase and alcohol dehydrogenase genes Antibiotic-resistance cassette2. Analysis of proper integration in genome, and of full segregation, by SouthernBlot 3. Expression analysis of genes in a single RNAm under inducing conditions, byNorthern Blot 4. Measurement of enzyme activities in cell extracts under inducing conditions 5. Verification of ethanol presence in outer medium