Recently, bio-fuels receive extensive attention as a renewable and environmental friendly alternative energy source due to the global issues of both greenhouse effects and conventional fossil fuels shortage. Microalgae, with the merits of environmental adaptability, high photosynthetic efficiency, neutral net carbon value and high lipid content, has become one of the most important raw materials for bio-fuels production, especially for the biodiesel production. In this paper, the advances of technology in microalgal culture with high lipid content are reviewed worldwide. The selection of high-lipid microalgae species, high-density culture of high-lipid microalgae and approaches to increase both the microalgal lipid content and the lipid production rate are discussed. The feasibility of microalgal lipid metabolism regulated by genetic engineering technology is then elaborated. The intensified microalgal culture modes using the membrane bioreactor integrated with CO2 exhaust gas as the carbon source are finally introduced. The integrated technology will further reduce the cost for microalgal lipid production and whilst making this process to be economical for the production of biodiesel.

Contents
1 Screening and Culture of High-lipid Microalgae
1.1 Screening of High-lipid Microalgae Species
1.2 High-density Culture of High-lipid Microalgae
2 Mechanism of Carbon Sequestration and Lipid Production by Microalgae
2.1 Carbon Sequestration by Microalgae and Its Connection with Lipid Metabolism
2.2 Mechanism of Microalgal Lipid Biosynthesis
3 Transfromation of Microalgae by Genetic Engineering Methodsv
3.1 Acetyl-coenzyme A Carboxylase (ACCase)
3.2 Diacylglycerol Acyl-transferase (DGAT) 3.3 Phosphoenolpyruvate Carboxylase (PEPC)
3.4 Problems Remained in Microalgae Transfromation by Genetic Engineering Methods
4 Culture Technology for Microalgal Lipid Content and Productivity Enhancement
5 Intensified Microalgal Culture by Membrane Bioreactor
6 Outlook