Growth Characteristics of Different Algal Species

Abstract

Algae are large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multi-cellular forms (Singh J, Gu S, Renew Sustain Energy Rev 14:2596–2610, 2010). Productivity of these photosynthetic microorganisms which converts CO2 into carbon-rich lipids is only a step or two away from biofuel which in turn is produced by several chemical, biochemical and thermochemical processes (Wijffels RH, Barbosa MJ, Science 329:796–799, 2010; Kirrolia A et al., Renew Sustain Energy Rev 20:642–656, 2013; Beneroso D et al., Bioresour Technol 144:240–246, 2013). Globally algal biofuel has been considered as 3rd and 4th generation biofuel based on its potential over 1st and 2nd generation crop based biofuels. Numerous scientists have discovered various applications of algal biomass apart from biofuel applications for the production of value added products to reduce its production cost towards bio-refinery approach (Rawat I et al., Appl Energy 103:444–467, 2013). Wijffels and Barbosa (Science 329:796–799, 2010) reported in Science about the broad prospect of microalgae over terrestrial crop based biofuel. In their report they mentioned how a 50-year-old concept came into focus during the oil crisis of 1970s. Since then over millions of algal species have been isolated, identified and studied towards its potential for biofuel and value added products. Table 3.1 represents microscopic view of some potential algal strains which has been studied as model organism at lab-scale and pilot-scale. Recent studies suggest that green algae are promising species bearing a substantial potential to obtain various products in a biorefinery concept (Suali E, Sarbatly R, Sustain Energy Rev 16:4316–4342, 2012). The algal oil can be transesterified to fatty acid methyl ester (FAME) and non-lipid components of algal biomass such as carbohydrates and proteins can be used for the production of bioethanol, biobutanol, neutraceuticals and animal feed (Kirrolia A et al., Renew Sustain Energy Rev 20:642–656, 2013). Moreover, the residue biomass cake can be used further to produce liquid fuel using the process of pyrolysis (Beneroso D et al., Bioresour Technol 144:240–246, 2013).