A MINI-REVIEW ON BIOFUELS FROM CHLAMYDOMONAS REINHARDTII

Abstract

This bibliographic review gives a concise overview of cultivation of microalgae for the production of biofuel. Chlamydomonas reinhardtii is one of the best microalgae that can be used for producing biofuel because of its simplicity of genome that allows it to be easily manipulated by genetic engineering for abundant growth. C. reinhardtii produces lipids under nitrogen deficient condition, which contains many triacylglycerols (TAGs) that influences the metabolism to a great extent and used for membrane remodeling. Several genes such as citrate synthase and DGAT2 involved in this mechanism were manipulated by engineering metabolic pathways to maximize lipid production under nitrogen deprived conditions. Additionally, C. reinhardtii can be efficiently cultivated and grown in closed photobioreactors, flat plate, tubular or vertical column with protected CO2 rather than open pond systems. In addition, C. reinhardtii can be harvested by several methods including Tris-Acetate Phosphate Pluronic (TAPP) medium method. Compared to conventional diesel, microalgae based biofuel, which is produced by trans-esterfication reactions, has a higher pour point temperature but similar properties. Contrasting Energy-efficiency ratio (EER) values of C. reinhardtii with those of other crops (Jatropha, palm oil and sunflower) is a crucial process before commercialization. The environmental impacts of microalgae are also beneficial in a way it can treat wastewater containing large amounts of nutrients such as nitrogen and phosphorus, which are beneficial for algae cultivation and produce bio-oil. However, this is a risky proposition as it can cause eutrophication and hypoxia in the ponds. Nevertheless, further research on bio-fuel production from C. reinhardtii must be carried out.