Howard P. Isermann Department of Chemical and Biological Engineering
and Center for Biotechnology and Interdisciplinary Studies
Rensselaer Polytechnic Institute
Troy, NY 12180, USA
Cell-free production of valuable molecules
​Cell-free production of valuable molecules is an exciting recent development. We focus here on biofuel production, a critical area of research for both a sustainable and a green future. The most popular approach for current biofuel production relies on fermentation and bioseparation. This procedure is limited by the toxicity of biofuels on cell viability and hence productivity. To avoid this, we have developed a cell-free system that can convert ketoisovaleric acid to isobutanol. Utilizing purified, mutant enzymes from different microbial sources, an optimized immobilized reaction was run. Immobilized reactions are favored for these processes as they better facilitate separation of the biofuel product from the reaction broth. Current research focus is on designing a separation scheme for the system and optimizing the enzymes further to improve yield.
(Left) Isobutanol synthesis pathway (Right) Wild type enzyme immobilized activity (l) vs free in solution (n) (A) MBP-KIVD normalized by initial absorbance (0.742), (B) ADH normalized by initial absorbance (1.82), and (C) FDH normalized by final free in solution absorbance (3.43).
Wong et al., (2019) Cell-Free Production of Isobutanol: A Completely Immobilized System. Bioresource Technology, 294, 122104.
Grimaldi et al., (2016) Towards cell-free isobutanol production: development of a novel immobilized enzyme system, Biotechnology progress, 32 (1) 66-73