Chapter 15 - The importance of microorganisms for biofuels production

Abstract

Microorganisms are fundamental and necessary to all living beings. Besides, they have relevant uses in a wide array of industrial processes and produce several metabolites. Concerning the production of biofuels, microorganisms are considered essential, whether for first, second, or third generation. In first-generation biofuels, the bioethanol production is based on the microbial fermentation of vegetable raw materials, whereas biodiesel can be obtained by using microbial enzymes. Similarly, second-generation bioethanol is also produced through fermentation, yet of lignocellulosic feedstock, which must be previously hydrolyzed by microbial enzymes. Microorganisms are also important in third-generation biofuels including bioethanol, biodiesel, biogas, and biohydrogen. Nowadays, a fourth generation of biofuels has emerged as an alternative; it is based on the metabolic engineering of microalgae aiming to improve and optimize biosynthesis. Thus, the use of microorganisms to produce renewable fuels is imperative to reduce environmental issues and ensure energy security.