Although significant literature and reports are available on microalgae growth, more work needs to be undertaken. Photobioreactors are expensive to scale, so direct secretion of fuel molecules from algae Dacomitinib has attracted interest as a way of reducing the cost of harvesting. Use of algal strains which naturally secrete lipids or algae engineered to secrete lipids from the direct photosynthetic conversion can help in decreasing the downstream processing costs . Both primary and secondary harvesting procedures are energy-intensive and expensive. Improving this aspect of algal processing will reduce costs associated with biogas and biodiesel production. Also, the development of more efficient and environmental friendly lipid extraction/transesterification processes is needed to improve the sustainability of algal biodiesel . At large scale applications the use of artificial media is not profitable or viable, therefore the use of wastewater and flue gas (or other waste streams) would be highly recommended for microalgae cultivation . The combination of wastewater treatment and other waste streams combined with anaerobic digestion of the microalgae after valuable lipids have been removed, improves the profitability of the plant considerably .