Biotechnological Interventions for Strain Improvement in Scenedesmus dimorphus Scenedesmus quadricauda and Chlorella spp

Abstract

Increasing energy demand and potential fossil fuel depletion has become most important concern for people throughout the world. In addition, global warming and climatic changes possibly caused due to the emission of green house gases are becoming contemporary issues [1– 3]. Possible solution is use of renewable energy sources like biomass, wind, solar, geothermal and hydropower. These are considered to decrease consumption of fossil fuels. Biomass is a renewable, carbon dioxide neutral and biodegradable source of energy with ample of resources, for instance, agricultural residue and waste, municipal solid waste, forestry waste, industrial waste, aquatic plants and terrestrial crops[4] . Among the available biofuel products from oil produced by terrestrial crops, biodiesel is at present an extensively used alternative fuel for transportation. However limited availability of land restricts the quantity of plant-based oil that can be generated for biodiesel production. Several microalgae as well as fungi species have capability of accumulating high lipid content that can be converted to many different forms of “drop-in” fuels like biodiesel [5–7]. Unlike conventional oilseed crops, microalgae show immense potential due to their wide range of applications. The algae biomass has potential to produce a variety of biofuels. Lipids from the algae biomass could be extracted and refined to fatty acids; the fatty acids can be further processed to produce biodiesel by transesterification. Gasification of the algal biomass by anaerobic digestion or thermal cracking can produce biogas. Carbohydrate fraction can be used for bioethanol production by direct fermentation. Pyrolysis or thermal degradation of biomass produces solid, liquid, and gaseous products. Anaerobic fermentation of biomass produces methane gas and direct combustion of biomass is used to generate power or syngas.