Chapter 11
Biofuels from Microalgae: Bioethanol
Reinaldo Gaspar Bastos
Abstract The industrial potential of ethanol has been tested early in 1800 to be
used as an engine fuel after the invention of an internal combustion engine.
Currently, there are three generations of bioethanol that have been flourished based
on different feedstocks. The first-generation bioethanol is derived from fermentation
of glucose contained in starch and/or sugar crops. USA and Brazil are the main
producers of bioethanol worldwide utilizing corn and sugarcane, while potato,
wheat, and sugar beet are the common feedstocks for bioethanol in Europe. The
term “second-generation bioethanol” emerged as a boon to overcome the “food
versus fuel” that occurs by the first-generation bioethanol. The second generation
also referred to as “advanced biofuels” is produced by innovative processes mainly
using lignocellulosic feedstock and agricultural forest residues. The emergence of
the third-generation bioethanol provides more benefits as compared to the first and
second generations and is focused on the use of microalgae and cyanobacteria.
These organisms represent as a promising alternative feedstock due to its high lipid
and carbohydrate contents, easy cultivation in a wide variety of water environment,
relatively low land usage and carbon dioxide absorption. This chapter will discuss
the use of microalgae for the ethanol production and the main technological routes,
i.e., enzymatic hydrolysis and yeast fermentation of microalgal biomass, metabolic
pathways in dark conditions, and “photofermentation.”
Keywords Bioethanol Á Microalgae Á Carbohydrate accumulation
Hydrolysis–fermentation
R. G. Bastos (&)
Center of Agricultural Sciences (CCA), Federal University of São Carlos (UFSCar),
Via Anhanguera, km 174, Araras, SP 13600-970, Brazil
e-mail: reinaldo.bastos@ufscar.br
© Springer International Publishing AG 2018
E. Jacob-Lopes et al. (eds.), Energy from Microalgae, Green Energy
and Technology, https://doi.org/10.1007/978-3-319-69093-3_11
229
Biofuels from Microalgae: Bioethanol
Reinaldo Gaspar Bastos
Abstract The industrial potential of ethanol has been tested early in 1800 to be
used as an engine fuel after the invention of an internal combustion engine.
Currently, there are three generations of bioethanol that have been flourished based
on different feedstocks. The first-generation bioethanol is derived from fermentation
of glucose contained in starch and/or sugar crops. USA and Brazil are the main
producers of bioethanol worldwide utilizing corn and sugarcane, while potato,
wheat, and sugar beet are the common feedstocks for bioethanol in Europe. The
term “second-generation bioethanol” emerged as a boon to overcome the “food
versus fuel” that occurs by the first-generation bioethanol. The second generation
also referred to as “advanced biofuels” is produced by innovative processes mainly
using lignocellulosic feedstock and agricultural forest residues. The emergence of
the third-generation bioethanol provides more benefits as compared to the first and
second generations and is focused on the use of microalgae and cyanobacteria.
These organisms represent as a promising alternative feedstock due to its high lipid
and carbohydrate contents, easy cultivation in a wide variety of water environment,
relatively low land usage and carbon dioxide absorption. This chapter will discuss
the use of microalgae for the ethanol production and the main technological routes,
i.e., enzymatic hydrolysis and yeast fermentation of microalgal biomass, metabolic
pathways in dark conditions, and “photofermentation.”
Keywords Bioethanol Á Microalgae Á Carbohydrate accumulation
Hydrolysis–fermentation
R. G. Bastos (&)
Center of Agricultural Sciences (CCA), Federal University of São Carlos (UFSCar),
Via Anhanguera, km 174, Araras, SP 13600-970, Brazil
e-mail: reinaldo.bastos@ufscar.br
© Springer International Publishing AG 2018
E. Jacob-Lopes et al. (eds.), Energy from Microalgae, Green Energy
and Technology, https://doi.org/10.1007/978-3-319-69093-3_11
229