AUTHOR=Kopp Dominik , Willows Robert D. , Sunna Anwar TITLE=Cell-Free Enzymatic Conversion of Spent Coffee Grounds Into the Platform Chemical Lactic Acid JOURNAL=Frontiers in Bioengineering and Biotechnology VOLUME=7 YEAR=2019 URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2019.00389 DOI=10.3389/fbioe.2019.00389 ISSN=2296-4185 ABSTRACT=
The coffee industry produces over 10 billion kg beans per year and generates high amounts of different waste products. Spent coffee grounds (SCG) are an industrially underutilized waste resource, which is rich in the polysaccharide galactomannan, a polysaccharide consisting of a mannose backbone with galactose side groups. Here, we present a cell-free reaction cascade for the conversion of mannose, the most abundant sugar in SCG, into L-lactic acid. The enzymatic conversion is based on a so far unknown oxidative mannose metabolism from