Nannochloropsis Oculata Algae As Biofuels: A Review On Two-Stage Culture

Nannochloropsis oculata, a unicellular green microalgae has become a new prospective for biofuel feedstock which offers a long term of sustainability and energy security. N. oculata accumulate high oil content which is about 28.7-29% oil by biomass weight with the daily oil production of 25.8 mg/day. To enhance the economic feasibility of microalgal-based biofuel production, it is necessary to improve both biomass productivity and lipid content. This paper reviews previous works on microalgae undergo mixotrophic conditions and nitrogen deficient conditions in order to observe the biomass productivity and lipid content for biofuel production. Many microalgae are capable of using many types of metabolism, such as photoautotrophic, heterotrophic, and mixotrophic. In heterotrophic condition, microalgae growth in the absence of sunlight derives energy completely from outsource organic carbon. While in mixotrophic condition, microalgae obtain energy from both photosynthesis reaction in the presence of sunlight and outsource organic carbon. Two stage culture system, is proposed where N. oculata will be grown in various carbon sources such as glucose, glycerol and starch in the first stage and nitrogen deficient condition in the second stage for lipid accumulation.