Batch and Continuous Studies of Chlorella Vulgaris in Photo-Bioreactors

Microalgae are unicellular, photosynthetic microorganisms, they have minimal nutrient requirements and are being used as source materials for a variety of products such as protein rich nutritional supplements, pharmaceutical chemicals and pigments (used in food and cosmetics). They also grow extremely fast, in comparison to plants and many microalgae strains are exceedingly rich in oil which makes them great candidates for the production of biodiesel. The strain Chlorella vulgaris, has shown a great promise as a source of oil and as being able to help in the treatment of wastewater. Despite all the advantages , the high cost of production in bioreactors still remains a limitation and much research is required. The production of microalgae (Chlorella vulgaris) in different photo-bioreactor configurations (4L flask, tubular and stirred tank reactor) was investigated, using different media formulations and in both batch and continuous operation (for PBR and CSTR). The effect of dilution rate and mixing speed were both studied in the case of CSTR. The highest overall specific growth rate (µ) was found when growing C. vulgaris in continuous operation in a tubular photo-bioreactor, µ = 0.7 d-1, which also reached the maximum biomass concentration of 0.79 g/L