Genetic engineering of algae

Nowadays, there is an increasing interest in the use of genetically engineered algae for industrial and biotechnological applications like wastewater treatment. Population overgrowth and industrial development has caused the release of organic pollutants and heavy metals into water bodies posing the ecosystem and human health at risk. Phycoremediation is seen as an effective way to reduce water pollution and producing algal biomass. Recently, algal biomass has been utilized as a sustainable and cost-effective feedstock for renewable biofuel production to decrease the negative environmental impact of fossil fuels. However, due to some limitations of algal native strains in cultivation, harvesting, and product extraction, which prevents reaching optimal biomass for phycoremediation and biofuel production at low costs, some investigation have been directed toward the genetic engineering of algae. Thus, some studies have shown the enhancement of phycoremediation systems using overexpression of enzymes involved in specific biochemical pathways to improve photosynthetic efficiency and growth in toxic concentrations of heavy metals. Also, in addition to using wastewater as a cheap and available nutrient supply for cultivation, genetic manipulation of algal biosynthetic pathways plays an important role in improving the growth and production rate of biofuel and reducing its cost. Therefore, finding and manipulating metabolic pathways of algae will elucidate some novel metabolically important genes which could enhance phycoremediation and its related byproducts. The present chapter is focused on genetic engineering of algae for improvement of phycoremediation and biofuel production. In addition, metabolic pathways and genetic engineering approaches are reviewed and discussed.