Using genetic engineering technique in two species of microalgae in order to increase the quantity and quality of lipids for biofuel production

• Grant number: 12/16271-0
• Support type: Scholarships abroad - Research Internship - Master's degree
• Effective date (Start): January 03, 2013
• Effective date (End): July 02, 2013
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal researcher: Pio Colepicolo Neto
• Grantee: Helena Dias Muller Villela
• Supervisor abroad: Richard T. Sayre
• Home Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Research place: Los Alamos National Laboratory, United States
• Associated to the scholarship: 11/16072-5 - Use of genetic and biochemical engeneiring in Chlamydomonas reinhardtii aiming the increase of the lipid level for biofuel production., BP.MS

Abstract

Several eukaryotic organisms have the ability to synthesize large quantities of oil in the form of triacylglycerols (TAGs), which are stored in lipid bodies and can be used for the production of biodiesel. Among these organisms, a group that has been considered promising are the microalgae, which have a high natural capacity for lipid storage, high growth rate and tolerance to diverse environmental conditions. Moreover, it is not necessary to use arable land or potable water for irrigation, and harvesting is continuous and can be performed every three days. Despite these advantages, microalgae are not widely used for biodiesel production because biomass is insufficient to supply a market with a so high demand, as is the fuel industry. For this reason, studies have been developed in order to increase both the amount of TAGs produced by microalgae, as well as its quality and growth rate of the producing organisms. Within this context, our group has been using genetic engineering to increase the amount of oil of the strain CC424 of the microalgae Chlamydomonas reinhardtii. The method of genetic transformation of this strain has been implemented in our laboratory according to Kindle (1990). Several clones in order to increase the amount of TAGs have already been achieved and the experiments of quantification of lipids and fatty acid profiles are already underway. In this new project we intend to continue using the method of genetic engineering of microalgae not only aiming to increase the amount of oil, but also to change the fatty acid profile of the oil in order to produce an excellent quality of biodiesel. For this purpose, the enzyme fatty acid desaturase 3 (FAD3), an enzyme which increases the level of unsaturation of fatty acids increasing their susceptibility to oxidation, will be underexpressed in C. reinhardtii and in Nannochloropsis sp. Thus, we will acquire knowledge in new techniques of genetic transformation of microalgae, since the method for Nannochloropsis is totally different from the method for C. reinhardtii. As an additional experiment, we intend to use different growth conditions in closed bioreactors to compare the impact of certain abiotic factors on the algae growth rate. (AU)