2024

Lak, Mandana; Marchlewicz, Ariel; Nojoumi, Seyed Ali; Ramezani, Mohadasseh; Harirchi, Sharareh

Currently, renewable resources are promising feedstocks for advanced biofuels (drop-in biofuels) production that can be directly used for the transportation sector in the world to overcome climate change and air pollution and contribute to the conservation of biodiversity. These renewable feedstocks, including agriculture residues, oily wastes, animal manures, or forest residues, can be utilized by various types of microorganisms from microalgae to bacteria to produce biofuels. Presently, existing biofuels cannot be directly employed into the engines and require specific infrastructures and modified engines, and this issue multiplies the importance of using drop-in biofuels. These advanced biofuels which have well-defined chemical constituents can be easily used in the existing fuel infrastructures. Different processes are used for the production of advanced biofuels, while the biochemical approach seems to be more effective as pure molecular streams of functionalized molecules can be manufactured. The heart of biochemical approach is microorganisms including yeasts, fungi, bacteria, and algae that hold the main answer for drop-in biofuels production. Among various microorganisms, bacteria are more likely to be well-matched for industrial production of advanced biofuels. In this chapter, after a short introduction to these biofuels, various feedstocks for bacterial utilization are explained, and latterly, technological frameworks and essential bacterial pathways for drop-in biofuels are discussed. Moreover, engineered bacterial pathways are included and in conclusion future perspectives of bacterial production approaches for drop-in biofuels are stated.