Centre for Microbial Electrosynthesis, The University of Queensland, Level 4, Gehrmann Laboratories Building (60), Brisbane, QLD, 4072, Australia. f.kracke@uq.edu.au.|Centre for Microbial Electrosynthesis, The University of Queensland, Level 4, Gehrmann Laboratories Building (60), Brisbane, QLD, 4072, Australia. j.kromer@uq.edu.au.