Microalgae lipid fuel production

Background

The use of photosynthetic microorganisms as sources of renewable energy has recently been the subject of much research and debate. Notably, microalgae lipid production has been considered as a potential source of biofuels that would not compete with food products. Other advantages include the atmospheric capture CO2 by algae, which might help neutralize the effects of later hydrocarbon combustion. Algae biofuel is also non-toxic and biodegradable and renewable.

Research Problem and Goals

There are many limitations to producing and extracting oil from algae, such as optimizing algae growth in bioreactors; lipid production and characteristics; extraction efficiency; and economic sustainability. We would like to improve the efficiency of algae energy production. Specifically, we will focus on the up-regulation of lipid biosynthesis, leading to increased fuel yield. High yields might help dispel initial cost worries. By using available genome sequence information from a variety of algae, as discoveries from other microorganism systems, we could select a point in the micro-algae lipid synthesis pathway to modify. Some options would be to increase expression of anabolic enzymes, or decrease inhibitory regulation mechanisms. Another possibility could be to add transform algae strains so as to extend the biosynthetic pathway of lipids in such a way that the biomass produced contains lipids that are closer to those that are used for combustion.

Societal Impact

• Making algae biofuels a more economically feasible source of biofuels
• Alternative to other biofuels sources that compete with food consumption

Sources

• Genetic Engineering of Algae for Enhanced Biofuel Production

Radakovits R, Jinkerson RE, Darzins A, Posewitz1 MC. Eukar Cell 2010 (9,4):486–501.

This review collects the current research regarding algae biofuels and summarizes the challenges that need to be addressed in order to make algae a viable source of biofuels. Some of the approaches proposed in this paper include: upgrading the direct biosynthesis of lipids, altering lipid characteristics so as to make them a more relevant fuel source, optimizing the conversion of carbohydrates to lipids, and improving photosynthetic efficiency. From this paper, which was just published this month, we gathered that there is great interest in developing algae biofuels as an energy source. As a consequence of this, there is ample opportunity for innovation and genetic optimization. This paper also contains numerous references that can serve as starting points for research ideas and tools

• Eichler-Stahlberg A, Weisheit W, Ruecker O, Heitzer M. Strategies to facilitate transgene expression in Chlamydomonas reinhardtii. Planta 229: 873-883.

• Vigeolas H, Waldeck P, Zank T, Geigenberger P. Increasing seed oil content in oil-seed rape (Brassica napus L.) by over-expression of yeast glycerlo-3-phosphate dehydrogenase under the control of a seed-specific promoter. Plant biotechnol. J. 5: 431-441.

• Some interesting presentations:

Engineering Challenges in Algae Energy

• Useful webpages:

UCSD Center for Algae Techology

• Potentially useful articles:

-Lu X, Vora H, Chaitan K. Overproduction of free fatty acids in E. coli: Implications for biodiesel production. Metab Eng 2008 (10;6): 333-339.

-Hu, Q., M. Sommerfeld, E. Jarvis, M. Ghirardi, M. Posewitz, M. Seibert, and A. Darzins. 2008. Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances. Plant J. 54:621–639.