Enhancing the Feasibility ofMicrocystis aeruginosaas a Feedstock for Bioethanol Production under the Influence of Various Factors

Abstract

Microcystis aeruginosa, a freshwater microalga, is capable of producing and accumulating different types of sugars in its biomass which make it a good feedstock for bioethanol production. Present study aims to investigate the effect of different factors increasing growth rate and carbohydrates productivity ofM. aeruginosa. MF media (modified BG11 media) and additional ingredients such as aminolevulinic acid (2 mM), lysine (2.28 mM), alanine (1 mM), and Naphthalene acetic acid (1 mM) as cytokine promotedM. aeruginosagrowth and sugar contents.Salmonellashowed growth-assisting effect onM. aeruginosa. Enhanced growth rate and carbohydrates contents were observed inM. aeruginosaculture grown at 25°C under red LED light of 90 μmolm−2s−1intensity. More greenish and carbohydrates richM. aeruginosabiomass was prepared (final OD660 nm= 2.21 and sugar contents 10.39 mM/mL) as compared to control (maximum OD660 nm= 1.4 and sugar contents 3 mM/mL). The final algae biomass was converted to algae juice through a specific pretreatment method. The resulted algae Juice was used as a substrate in fermentation process. Highest yield of bioethanol (50 mM/mL) was detected whenBrettanomyces custersainus,Saccharomyces cerevisiae, andPichia stipitiswere used in combinations for fermentation process as compared to their individual fermentation. The results indicated the influence of different factors on the growth rate and carbohydrates productivity ofM. aeruginosaand its feasibility as a feedstock for fermentative ethanol production.