The path to next generation biofuels: successes and challenges in the era of synthetic biology

Abstract

Volatility of oil prices along with major concerns about climate change, oil supply security and depleting reserves have sparked renewed interest in the production of fuels from renewable resources. Recent advances in synthetic biology provide new tools for metabolic engineers to direct their strategies and construct optimal biocatalysts for the sustainable production of biofuels. Metabolic engineering and synthetic biology efforts entailing the engineering of native and de novo pathways for conversion of biomass constituents to short-chain alcohols and advanced biofuels are herewith reviewed. In the foreseeable future, formal integration of functional genomics and systems biology with synthetic biology and metabolic engineering will undoubtedly support the discovery, characterization, and engineering of new metabolic routes and more efficient microbial systems for the production of biofuels.

Triacylglycerol Production from Corn Stover Using a Xylose-Fermenting Rhodococcus opacus Strain for Lignocellulosic Biofuels

“…Nevertheless, microbial technologies for efficiently converting lignocellulosic biomass to sustainable biomaterials and biofuels have not yet been established [15,16]. One of the vital challenges is efficient fermentations of the sugar mixtures, which contain glucose and xylose as major components, present in all hydrolysates of lignocellulosic biomass [17][18][19][20][21].…”

Anaerobic fermentation of glycerol: a platform for renewable fuels and chemicals

“…The availability of diverse biomass resources, such as agricultural lignocellulosic residues and edible and non-edible crops, has resulted in significant advancements in the conversion of biomass into renewable fuels and chemicals through the implementation of different technologies capable of utilizing specific biomass feedstock constituents [3][4][5][6][7][8]. Although the production of biofuels such as bioethanol from the most commonly used feedstocks on an industrial scale (starches and simple sugars derived from sources such as sugar cane and corn) is highly efficient [5], these feedstocks are expensive and non-sustainable due to their concurrent integration as an essential component of the food-feed chain.…”

“…Although the production of biofuels such as bioethanol from the most commonly used feedstocks on an industrial scale (starches and simple sugars derived from sources such as sugar cane and corn) is highly efficient [5], these feedstocks are expensive and non-sustainable due to their concurrent integration as an essential component of the food-feed chain. Even lignocellulosic crops, although highly productive, sustainable, and renewable, are difficult to convert into sugars leading to higher feedstock and operating costs [4,5]. In addition, similar economic and political factors have led to an increase in the feedstock and operating costs for biodiesel production that, at times, result in feedstock and operating costs that nearly match the market price of biodiesel [9].…”

Theoretical and Practical Studies on the Metabolic Engineering of Streptomyces for Production of Butanols

“…To act as a feedstock, the cellulose and hemi-cellulose must first be digested to low molecular weight sugars, and these are fermented to alcohols ( Figure 1). Microbes make a significant contribution to the production of biofuels [6][7]. However, the yield of product by native microbes is uneconomic, which makes it necessary to develop and improve them through strategies of systems and synthetic biology [8][9].…”