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Directed Evolution of a Bacterial Laccase (CueO) for Enzymatic Biofuel Cells
Author(s) -
Zhang Lingling,
Cui Haiyang,
Zou Zhi,
Garakani Tayebeh Mirzaei,
NovoaHenriquez Catalina,
Jooyeh Bahareh,
Schwaneberg Ulrich
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201814069
Subject(s) - redox , laccase , chemistry , enzyme , oxidase test , multicopper oxidase , biophysics , biochemistry , inorganic chemistry , biology
Escherichia coli's copper efflux oxidase (CueO) has rarely been employed in the cathodic compartment of enzymatic biofuel cells (EBFCs) due to its low redox potential (0.36 V vs. Ag/AgCl, pH 5.5) towards O 2 reduction. Herein, directed evolution of CueO towards a more positive onset potential was performed in an electrochemical screening system. An improved CueO variant (D439T/L502K) was obtained with a significantly increased onset potential (0.54 V), comparable to that of high‐redox‐potential fungal laccases. Upon coupling with an anodic compartment, the EBFC exhibited an open‐circuit voltage ( V oc ) of 0.56 V. Directed enzyme evolution by tailoring enzymes to application conditions in EBFCs has been validated and might, in combination with molecular understanding, enable future breakthroughs in EBFC performance