- Email: [email protected]
Influences of CO2 concentrations and salinity on acceleration of microalgal oil as raw material for biodiesel production
Special Abstracts / Journal of Biotechnology 150S (2010) S1–S576
[B.28] Cloning and bioinformatic characterization of genes controlling key steps of the fatty acid biosynthesis and lipid breakdown in seeds of Jatropha curcas L. D.G. Ambrosi, G. Galla, S. Collani, G. Barcaccia ∗ Laboratory of Plant Genetics and Genomics, University of Padua, Italy Keywords: Jatropha curcas; Gene cloning; Lipid metabolism; Biofuel Jatropha curcas L. (2n = 2x = 22) is becoming a popular non-food oleaginous crop in several developed countries for its proposed value in the biopharmaceutical industry. Despite the potentials of its oil-rich seeds as a renewable source of biodiesel and an interest in large-scale cultivation, relatively little is known with respect to population genetics and plant genomics. We recently performed genomic DNA markers and FCSS analyses to gain insights on ploidy variation and heterozygosity levels of multiple accessions, and genomic relationships among commercial varieties and locally dominant ecotypes grown in different geographical areas. Seeds commercialized worldwide seem to include a few closely related genotypes showing high degrees of homozygosity for single varieties and very low genetic diversity between varieties. For a better understanding of oil production and accumulation in J. curcas seeds, it would be useful to clone and characterize genes controlling key steps of FA biosynthesis and lipid breakdown pathways. Gene bank searches and bioinformatic analyses allowed us to select 13 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 desaturase, and acyl-ACP thioesterase II), and their nucleotide and amino acid sequences are available in the NCBI databases. The remaining eight genes were cloned in the present study (i.e., ATP-citrate lyase, acetyl-CoA carboxylase II, 3-ketoacyl-ACP II, 3ketoacyl-ACP reductase, 3-hydroxyacyl-ACP dehydrase, enoyl-ACP reductase, acyl-ACP thioesterase I, and acyl-CoA dehydrogenase). Replicated cDNA samples were produced by retrotranscription of mRNAs isolated from mature seeds belonging to different commercial varieties and Mexican ecotypes. Gene expression levels were assayed by quantitative Real-Time PCR with genespecific primer combinations. The haplotyping of single accessions will be attempted using a worldwide collection of J. curcas materials to find out the most representative and discriminant SNPs related to FA biosynthesis and lipid metabolism genes. doi:10.1016/j.jbiotec.2010.08.061 [B.29] Development of innovative technologies for the optimal culturing 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 2
R&M Division - Downstream Process Technology (SDM-PROC), Italy Energy Env Processes and Technologies (PTEA), Italy
Microalgae represent a potentially interesting type of biomass to be used as a source of molecules that can be refined and upgraded to biofuels. In fact the biological characteristics of growth and lipid accumulation make microalgal strains different enough from other vegetal species to offer new prospective scenarios of exploitation as energy biomass in comparison to other plants and microorganisms.
S19
Still significant scientific and technological issues at the basis of biomass productivity and economic fuel production have to be studied and solved to achieve efficient processes and potentially economical production cycles. Pilot sized experimental apparati located at a refinery site allow recent experimentation at a scale necessary to evaluate some of the fundamental issues involved in the assessment of industrial applicability and to refine the colturing and work up technologies involved in the biomass to fuel production. In this occasion recent results will be presented on the optimization of culturing processes, and the development of molecular methods for the characterization of pond-grown microalgal consortia. doi:10.1016/j.jbiotec.2010.08.062 [B.30] Influences of CO2 concentrations and salinity on acceleration of microalgal oil as raw material for biodiesel production Prayoon Enmak 1,2,∗ , Pakawadee Kaewkannetra 2,3 1
School of Khon Kaen University, Khon Kaen 40002, Thailand Centre for Alternative Energy Research and Development (AERD), Faculty of Engineering, Khon Kaen University, Khon Kaen 40002, Thailand 3 Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand Keywords: CO2 ; Salinity; Microalgal oil; Scenedesmus obliquus; Biodiesel 2
In this work, several microalgae samples were collected from natural water basins in northern area of Thailand using micropipette technique. The isolation step was investigated by regular observation under microscope technique. The algal strains were enriched in modified Chu 13 medium. The morphology of the algal isolated strain showed in a green unicellular colony thereafter as identified as Scenedesmus obliquus. Then, growth monitoring was performed in 3L vertical tubular glass photo-reactors containing modified Chu 13 medium under autotrophic cultivations (16:8 h of light dark cycle using cool white fluorescent at room temperature) coupling which injection of different CO2 concentrations (5, 10 and 15%) mixed with ambient air for achieving the maximum algal biomass. The results revealed that the S. Obliquus can be grown in all variations of CO2 concentrations. Moreover, it was found that the algal biomass yields increased as CO2 concentrations 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 was considered. Sodium chloride (NaCl) solutions (0.1, 0.2 and 0.3 M) were prepared with deionized water and then were added into the cultures when the algal cells reached at early stationary phase (salt stress period). The algal biomass was harvested at day 5th, 10th and 15th after salt stress. Biodiesel was performed by in-situ acidic transesterification. The biodiesel property obtained was subjected to American Society for Testing and Materials Standard (ASTM), such as flash point, pH, density and viscosity. doi:10.1016/j.jbiotec.2010.08.063
[B.28] Cloning and bioinformatic characterization of genes controlling key steps of the fatty acid biosynthesis and lipid breakdown in seeds of Jatropha curcas L. D.G. Ambrosi, G. Galla, S. Collani, G. Barcaccia ∗ Laboratory of Plant Genetics and Genomics, University of Padua, Italy Keywords: Jatropha curcas; Gene cloning; Lipid metabolism; Biofuel Jatropha curcas L. (2n = 2x = 22) is becoming a popular non-food oleaginous crop in several developed countries for its proposed value in the biopharmaceutical industry. Despite the potentials of its oil-rich seeds as a renewable source of biodiesel and an interest in large-scale cultivation, relatively little is known with respect to population genetics and plant genomics. We recently performed genomic DNA markers and FCSS analyses to gain insights on ploidy variation and heterozygosity levels of multiple accessions, and genomic relationships among commercial varieties and locally dominant ecotypes grown in different geographical areas. Seeds commercialized worldwide seem to include a few closely related genotypes showing high degrees of homozygosity for single varieties and very low genetic diversity between varieties. For a better understanding of oil production and accumulation in J. curcas seeds, it would be useful to clone and characterize genes controlling key steps of FA biosynthesis and lipid breakdown pathways. Gene bank searches and bioinformatic analyses allowed us to select 13 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 desaturase, and acyl-ACP thioesterase II), and their nucleotide and amino acid sequences are available in the NCBI databases. The remaining eight genes were cloned in the present study (i.e., ATP-citrate lyase, acetyl-CoA carboxylase II, 3-ketoacyl-ACP II, 3ketoacyl-ACP reductase, 3-hydroxyacyl-ACP dehydrase, enoyl-ACP reductase, acyl-ACP thioesterase I, and acyl-CoA dehydrogenase). Replicated cDNA samples were produced by retrotranscription of mRNAs isolated from mature seeds belonging to different commercial varieties and Mexican ecotypes. Gene expression levels were assayed by quantitative Real-Time PCR with genespecific primer combinations. The haplotyping of single accessions will be attempted using a worldwide collection of J. curcas materials to find out the most representative and discriminant SNPs related to FA biosynthesis and lipid metabolism genes. doi:10.1016/j.jbiotec.2010.08.061 [B.29] Development of innovative technologies for the optimal culturing 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 2
R&M Division - Downstream Process Technology (SDM-PROC), Italy Energy Env Processes and Technologies (PTEA), Italy
Microalgae represent a potentially interesting type of biomass to be used as a source of molecules that can be refined and upgraded to biofuels. In fact the biological characteristics of growth and lipid accumulation make microalgal strains different enough from other vegetal species to offer new prospective scenarios of exploitation as energy biomass in comparison to other plants and microorganisms.
S19
Still significant scientific and technological issues at the basis of biomass productivity and economic fuel production have to be studied and solved to achieve efficient processes and potentially economical production cycles. Pilot sized experimental apparati located at a refinery site allow recent experimentation at a scale necessary to evaluate some of the fundamental issues involved in the assessment of industrial applicability and to refine the colturing and work up technologies involved in the biomass to fuel production. In this occasion recent results will be presented on the optimization of culturing processes, and the development of molecular methods for the characterization of pond-grown microalgal consortia. doi:10.1016/j.jbiotec.2010.08.062 [B.30] Influences of CO2 concentrations and salinity on acceleration of microalgal oil as raw material for biodiesel production Prayoon Enmak 1,2,∗ , Pakawadee Kaewkannetra 2,3 1
School of Khon Kaen University, Khon Kaen 40002, Thailand Centre for Alternative Energy Research and Development (AERD), Faculty of Engineering, Khon Kaen University, Khon Kaen 40002, Thailand 3 Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand Keywords: CO2 ; Salinity; Microalgal oil; Scenedesmus obliquus; Biodiesel 2
In this work, several microalgae samples were collected from natural water basins in northern area of Thailand using micropipette technique. The isolation step was investigated by regular observation under microscope technique. The algal strains were enriched in modified Chu 13 medium. The morphology of the algal isolated strain showed in a green unicellular colony thereafter as identified as Scenedesmus obliquus. Then, growth monitoring was performed in 3L vertical tubular glass photo-reactors containing modified Chu 13 medium under autotrophic cultivations (16:8 h of light dark cycle using cool white fluorescent at room temperature) coupling which injection of different CO2 concentrations (5, 10 and 15%) mixed with ambient air for achieving the maximum algal biomass. The results revealed that the S. Obliquus can be grown in all variations of CO2 concentrations. Moreover, it was found that the algal biomass yields increased as CO2 concentrations 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 was considered. Sodium chloride (NaCl) solutions (0.1, 0.2 and 0.3 M) were prepared with deionized water and then were added into the cultures when the algal cells reached at early stationary phase (salt stress period). The algal biomass was harvested at day 5th, 10th and 15th after salt stress. Biodiesel was performed by in-situ acidic transesterification. The biodiesel property obtained was subjected to American Society for Testing and Materials Standard (ASTM), such as flash point, pH, density and viscosity. doi:10.1016/j.jbiotec.2010.08.063