Special Abstracts / Journal of Biotechnology 150S (2010) S1–S576 S19

[B.28]

Cloning and bioinformatic characterization of genes controllingkey steps of the fatty acid biosynthesis and lipid breakdown inseeds of Jatropha curcas L.

D.G. Ambrosi, G. Galla, S. Collani, G. Barcaccia ∗

Laboratory of Plant Genetics and Genomics, University of Padua, ItalyKeywords: Jatropha curcas; Gene cloning; Lipid metabolism; Bio-fuel

Jatropha curcas L. (2n = 2x = 22) is becoming a popular non-foodoleaginous crop in several developed countries for its proposedvalue in the biopharmaceutical industry. Despite the potentialsof its oil-rich seeds as a renewable source of biodiesel andan interest in large-scale cultivation, relatively little is knownwith respect to population genetics and plant genomics. Werecently performed genomic DNA markers and FCSS analysesto gain insights on ploidy variation and heterozygosity lev-els of multiple accessions, and genomic relationships amongcommercial varieties and locally dominant ecotypes grown indifferent geographical areas. Seeds commercialized worldwideseem to include a few closely related genotypes showing highdegrees of homozygosity for single varieties and very lowgenetic diversity between varieties. For a better understand-ing of oil production and accumulation in J. curcas seeds, itwould be useful to clone and characterize genes controlling keysteps of FA biosynthesis and lipid breakdown pathways. Genebank searches and bioinformatic analyses allowed us to select13 genes encoding for enzymes involved in lipid metabolism.Five of these genes were previously isolated in J. curcas (i.e.,acetyl-CoA carboxylase I, 3-ketoacyl-ACP I and III, acyl-ACP desat-urase, and acyl-ACP thioesterase II), and their nucleotide andamino acid sequences are available in the NCBI databases. Theremaining eight genes were cloned in the present study (i.e.,ATP-citrate lyase, acetyl-CoA carboxylase II, 3-ketoacyl-ACP II, 3-ketoacyl-ACP reductase, 3-hydroxyacyl-ACP dehydrase, enoyl-ACPreductase, acyl-ACP thioesterase I, and acyl-CoA dehydrogenase).Replicated cDNA samples were produced by retrotranscriptionof mRNAs isolated from mature seeds belonging to differentcommercial varieties and Mexican ecotypes. Gene expressionlevels were assayed by quantitative Real-Time PCR with gene-specific primer combinations. The haplotyping of single accessionswill be attempted using a worldwide collection of J. curcasmaterials to find out the most representative and discrimi-nant SNPs related to FA biosynthesis and lipid metabolismgenes.

doi:10.1016/j.jbiotec.2010.08.061

[B.29]

Development of innovative technologies for the optimal cultur-ing and characterization of microalgae as energy biomass

G. Carpani 1,2, F. Capuano 1,2, E. D’addario 1,2, F. de Ferra 1,2,∗

1 R&M Division - Downstream Process Technology (SDM-PROC), Italy2 Energy Env Processes and Technologies (PTEA), Italy

Microalgae represent a potentially interesting type of biomassto be used as a source of molecules that can be refined and upgradedto biofuels. In fact the biological characteristics of growth and lipidaccumulation make microalgal strains different enough from othervegetal species to offer new prospective scenarios of exploitation asenergy biomass in comparison to other plants and microorganisms.

Still significant scientific and technological issues at the basisof biomass productivity and economic fuel production have to bestudied and solved to achieve efficient processes and potentiallyeconomical production cycles.

Pilot sized experimental apparati located at a refinery site allowrecent experimentation at a scale necessary to evaluate some ofthe fundamental issues involved in the assessment of industrialapplicability and to refine the colturing and work up technologiesinvolved in the biomass to fuel production.

In this occasion recent results will be presented on the opti-mization of culturing processes, and the development of molecularmethods for the characterization of pond-grown microalgal con-sortia.

doi:10.1016/j.jbiotec.2010.08.062

[B.30]

Influences of CO2 concentrations and salinity on acceleration ofmicroalgal oil as raw material for biodiesel production

Prayoon Enmak 1,2,∗, Pakawadee Kaewkannetra 2,3

1 School of Khon Kaen University, Khon Kaen 40002, Thailand2 Centre for Alternative Energy Research and Development (AERD),Faculty of Engineering, Khon Kaen University, Khon Kaen 40002, Thai-land3 Department of Biotechnology, Faculty of Technology, Khon Kaen Uni-versity, Khon Kaen 40002, ThailandKeywords: CO2; Salinity; Microalgal oil; Scenedesmus obliquus;Biodiesel

In this work, several microalgae samples were collectedfrom natural water basins in northern area of Thailand usingmicropipette technique. The isolation step was investigated by reg-ular observation under microscope technique. The algal strainswere enriched in modified Chu 13 medium. The morphology of thealgal isolated strain showed in a green unicellular colony thereafteras identified as Scenedesmus obliquus. Then, growth monitoring wasperformed in 3L vertical tubular glass photo-reactors containingmodified Chu 13 medium under autotrophic cultivations (16:8 hof light dark cycle using cool white fluorescent at room temper-ature) coupling which injection of different CO2 concentrations(5, 10 and 15%) mixed with ambient air for achieving the maxi-mum algal biomass. The results revealed that the S. Obliquus canbe grown in all variations of CO2 concentrations. Moreover, it wasfound that the algal biomass yields increased as CO2 concentra-tions increase. The maximum biomass was obtained at 2.18 gL−1

(dry cell weight) when 15% CO2 concentration was used. Hereafter,the effect of salinity on the oil accumulation in the S. Obliquus wasconsidered. Sodium chloride (NaCl) solutions (0.1, 0.2 and 0.3 M)were prepared with deionized water and then were added into thecultures when the algal cells reached at early stationary phase (saltstress period). The algal biomass was harvested at day 5th, 10thand 15th after salt stress. Biodiesel was performed by in-situ acidictransesterification. The biodiesel property obtained was subjectedto American Society for Testing and Materials Standard (ASTM),such as flash point, pH, density and viscosity.

doi:10.1016/j.jbiotec.2010.08.063