Biosynthesis of Fatty Alcohols in Engineered Microbial Cell Factories: Advances and Limitations

Abstract

Concerns about climate change and environmental destruction have led to interest in technologies that can replace fossil fuels and petrochemicals with compounds derived from sustainable sources that have lower environmental impact. Fatty alcohols produced by chemical synthesis from ethylene or by chemical conversion of plant oils have a large range of industrial applications. These chemicals can be synthesized through biological routes but their free forms are produced in trace amounts naturally. This review focuses on how genetic engineering of endogenous fatty acid metabolism and heterologous expression of fatty alcohol producing enzymes have come together resulting in the current state of the field for production of fatty alcohols by microbial cell factories. We provide an overview of endogenous fatty acid synthesis, enzymatic methods of conversion to fatty alcohols and review the research to date on microbial fatty alcohol production. The primary focus is on work performed in the model microorganisms, Escherichia coli and Saccharomyces cerevisiae but advances made with cyanobacteria and oleaginous yeasts are also considered. The limitations to production of fatty alcohols by microbial cell factories are detailed along with consideration to potential research directions that may aid in achieving viable commercial scale production of fatty alcohols from renewable feedstock.

Reconfiguring workup steps in multi-cycle extractive bioconversion for sustainable fatty alcohol production: a process engineering approach

“…1 The demand for fatty alcohols is forecasted to grow significantly in 2023. 1,2 The use of engineered cells possessing metabolically engineered pathways capable of producing fatty alcohols emerges as a sustainable route of production. This approach enables the production of fatty alcohols from sugars, which is an abundant resource, particularly in Asia.…”

“…The COVID-19 outbreak has greatly increased the demand for such products, with the global market size of fatty alcohols forecasted to skyrocket to 10 billion USD by 2023. 1,2 Fatty alcohols are produced largely from petro-based and bio-based feedstocks via the Ziegler process and catalytic hydrogenation, respectively. 3 These processes require metal catalysts and relatively high temperatures.…”

Recent Progress and Trends in the Development of Microbial Biofuels from Solid Waste—A Review

“…Recently, there has been a successful commercialization of farnesene production [47]. In addition, several authors have recently reported insights on using synthetic biology and engineered microorganisms and enzymes for the production of microbial fuels [9,17,22,42,49].…”

“…The microbial synthesis of fatty acids (FAs) and their conversion into phospholipids is a well understood metabolic process [49]. The cultivating microorganisms in nutrient media with limited nitrogen, phosphorous, or sulfur has been used to switch from a growth phase to a FA synthesis and storage phase [49].…”

“…The microbial synthesis of fatty acids (FAs) and their conversion into phospholipids is a well understood metabolic process [49]. The cultivating microorganisms in nutrient media with limited nitrogen, phosphorous, or sulfur has been used to switch from a growth phase to a FA synthesis and storage phase [49]. Despite the inability to utilize free FAs as drop-in fuels, their byproducts, such as fatty alcohols, fatty acid alkyl esters, fatty acid-derived alkanes, and alkenes, are high-value biofuel precursors for a number of reasons, such as low solubility in water, greater energy density, and reduced toxicity to the producing hosts [50,51].…”