Methods in Molecular Biology (2020) 1980: 153–172
DOI 10.1007/7651_2018_205
© Springer Science+Business Media New York 2019
Published online: 22 January 2019
Metabolic Engineering of Microalgae for Biofuel Production
Mohammad Pooya Naghshbandi, Meisam Tabatabaei,
Mortaza Aghbashlo, Muhammad Nauman Aftab, and Irfana Iqbal
Abstract
Microalgae are considered as promising cell factories for the production of various types of biofuels,
including bioethanol, biodiesel, and biohydrogen by using carbon dioxide and sunlight. In spite of unique
advantages of these microorganisms, the commercialization of microalgal biofuels has been hindered by
poor economic features. Metabolic engineering is among the most promising strategies put forth to
overcome this challenge. In this chapter, metabolic pathways involved in lipid and hydrogen production
by microalgae are reviewed and discussed. Moreover, metabolic and genetic engineering approaches
investigated for improving the rate of lipid (as a feedstock for biodiesel production) and biohydrogen
synthesis are presented. Finally, genetic engineering tools and approaches employed for engineering
microalgal metabolic pathways are elaborated. A thorough step-by-step protocol for reconstructing the
metabolic pathway of various microorganisms including microalgae is also presented.
Keywords Microalgae, Biodiesel, Biohydrogen, Genetic engineering, Metabolic engineering
1 Introduction
Microalgae are photosynthetic cell factories and have been the
center of research activities aimed at producing a wide array of
bioproducts including biofuels [1]. In spite of the fact that the
economic feasibility of algal fuels has been seriously questioned
recently [2, 3], the unique features of these organisms such as fast
growth rate, high lipid and/or carbohydrate content, growing in
unconventional water resources, and being capable of photobiological production of biohydrogen are still motivating [4, 5]. In addition to that, it is generally believed that algal fuels could be regarded
as solution to the growing environmental concerns, i.e., global
warming and climate change, mainly caused by the widespread
combustion of fossil fuels. It has been estimated that the combustion of biofuels of microalgae origin could potentially mitigate CO 2 ,
SO x , and particulate matters (PMs) by 78%, 98%, and 50%, respectively [6, 7]. It should also be mentioned that microalgae possess
another environmental-related benefit associated with their capability in fixing a large amount of atmospheric CO 2 (i.e., 183 tons of
CO 2 /100 tons of microalgal biomass) [8]. Therefore, it could be
153
DOI 10.1007/7651_2018_205
© Springer Science+Business Media New York 2019
Published online: 22 January 2019
Metabolic Engineering of Microalgae for Biofuel Production
Mohammad Pooya Naghshbandi, Meisam Tabatabaei,
Mortaza Aghbashlo, Muhammad Nauman Aftab, and Irfana Iqbal
Abstract
Microalgae are considered as promising cell factories for the production of various types of biofuels,
including bioethanol, biodiesel, and biohydrogen by using carbon dioxide and sunlight. In spite of unique
advantages of these microorganisms, the commercialization of microalgal biofuels has been hindered by
poor economic features. Metabolic engineering is among the most promising strategies put forth to
overcome this challenge. In this chapter, metabolic pathways involved in lipid and hydrogen production
by microalgae are reviewed and discussed. Moreover, metabolic and genetic engineering approaches
investigated for improving the rate of lipid (as a feedstock for biodiesel production) and biohydrogen
synthesis are presented. Finally, genetic engineering tools and approaches employed for engineering
microalgal metabolic pathways are elaborated. A thorough step-by-step protocol for reconstructing the
metabolic pathway of various microorganisms including microalgae is also presented.
Keywords Microalgae, Biodiesel, Biohydrogen, Genetic engineering, Metabolic engineering
1 Introduction
Microalgae are photosynthetic cell factories and have been the
center of research activities aimed at producing a wide array of
bioproducts including biofuels [1]. In spite of the fact that the
economic feasibility of algal fuels has been seriously questioned
recently [2, 3], the unique features of these organisms such as fast
growth rate, high lipid and/or carbohydrate content, growing in
unconventional water resources, and being capable of photobiological production of biohydrogen are still motivating [4, 5]. In addition to that, it is generally believed that algal fuels could be regarded
as solution to the growing environmental concerns, i.e., global
warming and climate change, mainly caused by the widespread
combustion of fossil fuels. It has been estimated that the combustion of biofuels of microalgae origin could potentially mitigate CO 2 ,
SO x , and particulate matters (PMs) by 78%, 98%, and 50%, respectively [6, 7]. It should also be mentioned that microalgae possess
another environmental-related benefit associated with their capability in fixing a large amount of atmospheric CO 2 (i.e., 183 tons of
CO 2 /100 tons of microalgal biomass) [8]. Therefore, it could be
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