Su-Chiung Fang

Biotechnology Center in Southern Taiwan, Academia Sinica
Agricultural Biotechnology Research Center, Academia Sinica
Tainan, Taiwan R. O.C.

3.1 INTRODUCTION

Compared to other biofuel feedstocks, microalgae are the preferred option for many reasons:

1. They grow extremely fast and hence produce high biomass yield quickly.

2. Microalgae-based fuels do not compete with the food supply and hence present no food security concerns.

3. Biofuels generated from microalgae are renewable and can be carbon-reducing [generation of 100 tons of algal biomass is equivalent to removing roughly 183 tons of carbon dioxide from the atmosphere (Chisti, 2008)].

4. Microalgal farming does not require arable land and can utilize industrial flue gas as a carbon source.

5. Selected oleaginous microalgae do not require fresh water and can grow in seawater, brackish water, or waste water.

6. Biodiesel fuels derived from microalgae can be integrated into the current transportation infrastructure.

During the past few years, there have been significant advances in uncovering molecular components required for production of fuel molecules in microalgae. The availability of ge­nomic sequences in the model green alga Chlamydomonas reinhardtii has accelerated forward genetic analysis and allowed for the use of reverse genetic approaches to uncover molecular mechanisms associated with fuel production (Merchant et al., 2007). Moreover, tran — scriptomics, proteomics, and metabolomics studies have provided new insights into gene regulation networks and coordinated cellular activities governing physiological flexibility and metabolic adaptation of microalgae. Understanding the basis of microalgal biology is important in laying the foundation for innovative strategies and for ultimate development of fuel surrogates. This review summarizes recent progress in elucidating molecular and cellular mechanisms of cellular physiology that are relevant to fuel production in microalgal systems, with an emphasis on developing metabolic engineering strategies to increase fuel production.