Cell-based and cell-free biocatalysis for the production of d-glucaric acid

Abstract

Abstractd-Glucaric acid (GA) is a value-added chemical produced from biomass, and has potential applications as a versatile platform chemical, food additive, metal sequestering agent, and therapeutic agent. Marketed GA is currently produced chemically, but increasing demand is driving the search for eco-friendlier and more efficient production approaches. Cell-based production of GA represents an alternative strategy for GA production. A series of synthetic pathways for GA have been ported into Escherichia coli, Saccharomyces cerevisiae and Pichia pastoris, respectively, and these engineered cells show the ability to synthesize GA de novo. Optimization of the GA metabolic pathways in host cells has leapt forward, and the titer and yield have increased rapidly. Meanwhile, cell-free multi-enzyme catalysis, in which the desired pathway is constructed in vitro from enzymes and cofactors involved in GA biosynthesis, has also realized efficient GA bioconversion. This review presents an overview of studies of the development of cell-based GA production, followed by a brief discussion of potential applications of biosensors that respond to GA in these biosynthesis routes.

Photocatalytic Biorefinery to Lactic Acid: A Carbon Nitride Framework with O Atoms Replacing the Graphitic N Linkers Shows Fast Migration/Separation of Charge

“…Furthermore, the efficient application of biomass‐derived feedstocks for the supply of energy and chemical feedstocks is essential for a biobased economy [11,12] . The traditional methods for reforming biomass to chemicals include thermal catalysis, [13] pyrolysis [14] and bio‐catalysis [15] . Electrocatalysis and photocatalysis have recently emerged as biomass‐reforming processes with excellent activities [16–20] .…”

“…[11,12] The traditional methods for reforming biomass to chemicals include thermal catalysis, [13] pyrolysis [14] and bio-catalysis. [15] Electrocatalysis and photocatalysis have recently emerged as biomassreforming processes with excellent activities. [16][17][18][19][20] However, the former is energy-intensive, whereas the latter not only exhibits high-efficiency, low energy consumption, low cost, easy operation and mild reaction conditions but it also serves as an effective route for solar energy utilization.…”

(Chemo)biocatalytic Upgrading of Biobased Furanic Platforms to Chemicals, Fuels, and Materials: A Comprehensive Review

“…More efforts should be devoted to the development of biocompatible chemical catalytic systems for the production of biobased furans as well as robust biocatalysts (e.g., enzymes from extremophiles) , capable of effectively converting the crude furans in the complex reaction mixtures (likely containing chemical catalysts and organic solvents). Additionally, biocatalysis may be applied for the selective transformation of biomass feedstocks (e.g., glucose and galactose) to platform intermediates (e.g., aldaric acids), followed by subsequent upgrading to the furan-based products via chemocatalysis. , Given the fact that the productivities of most biocatalyst processes remain inadequate for industrial implementation, extensive process optimization (e.g., catalysts/their appropriate combinations (for multienzyme systems), solvent systems, and reaction conditions) coupled with product isolation (e.g., ISPR) is urgently required. In addition, the microbial production of biofuels via fermentation of lignocellulosic hydrolysates has been investigated for several decades; a variety of strategies for enhancing microbial tolerance to inhibitors such as furans and acids have been well established. − Some strategies such as tolerance and evolutionary engineering may be applied to improve the catalytic performances of biocatalysts in the furan field. …”

Alternative design strategies to help build the enzymatic retrosynthesis toolbox

“…However, these strategies are limited in industrial fermentation methods due to low conversion rates, unbalanced pathway fluxes, and issues of cellular acid toxicity. [48][49] Cell-free methods were similarly developed by Lou for the production of D-glucaric acid from sucrose whereby addition of a single NAD + regenerative enzyme was able to significantly increase the overall efficiency of this pathway. 41 Beyond the benefits and capabilities described here, such minimalist enzymatic systems also provide a potent format for implementing the next area of discussion.…”