title: Cell-free biosystems for biomanufacturing.
abstract: Although cell-free biosystems have been used as a tool for investigating fundamental aspects of biological systems for more than 100 years, they are becoming an emerging biomanufacturing platform in the production of low-value biocommodities (e.g., H(2), ethanol, and isobutanol), fine chemicals, and high-value protein and carbohydrate drugs and their precursors. Here we would like to define the cell-free biosystems containing more than three catalytic components in a single reaction vessel, which although different from one-, two-, or three-enzyme biocatalysis can be regarded as a straightforward extension of multienzymatic biocatalysis. In this chapter, we compare the advantages and disadvantages of cell-free biosystems versus living organisms, briefly review the history of cell-free biosystems, highlight a few examples, analyze any remaining obstacles to the scale-up of cell-free biosystems, and suggest potential solutions. Cell-free biosystems could become a disruptive technology to microbial fermentation, especially in the production of high-impact low-value biocommodities mainly due to the very high product yields and potentially low production costs.
authors.affiliation: Biological Systems Engineering Department, Virginia Tech, 304 Seitz Hall, Blacksburg, VA, 24061, USA.
authors.forename: Chun
authors.initials: C
authors.lastname: You
authors.forename: Y-H Percival
authors.initials: YH
authors.lastname: Zhang
mesh_terms: D055162:Biocatalysis; D001685:Biological Factors / Q000096:biosynthesis; D001709:Biotechnology / Q000295:instrumentation / Q000379:methods*; D000440:Butanols / Q000378:metabolism; D002458:Cell Fractionation; D048013:Acetivibrio thermocellus / Q000737:chemistry / Q000201:enzymology*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry / Q000201:enzymology*; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D007700:Kinetics; D009097:Multienzyme Complexes; D013347:Subcellular Fractions / Q000201:enzymology; D020124:Thermotoga maritima / Q000737:chemistry / Q000201:enzymology*
chemical_list: D001685:Biological Factors; D000440:Butanols; D004800:Enzymes, Immobilized; D009097:Multienzyme Complexes; D000431:Ethanol; C040507:isobutyl alcohol