Electrochemical monitoring of the bio-assimilation of 1,4-butanediol by Acetobacter aceti for bio-upcycling

The bioconversion of plastic-derived monomers, such as 1,4-butanediol (1,4-BD), into value-added chemicals is a promising strategy for sustainable bio-upcycling, yet its monitoring still relies on time-consuming and instrument-intensive techniques, such as chromatography. Here, we report a simple and effective electrochemical approach for time-course monitoring of 1,4-BD bio-assimilation in bacterial cultures. A wild-type strain of Acetobacter aceti isolated from the gut of Drosophila melanogaster, and capable of using 1,4-BD as the sole carbon source in the absence of glucose, is employed as a model system. Gold thin film electrodes fabricated via Print-Light-Synthesis are integrated into a 3D-printed miniaturized electrochemical microcell and applied directly to culturederived samples. The as-printed electrodes enable sensitive and linear quantification of 1,4-BD in complex bacterial media over a concentration range of 2–80 mmol L−1. The method requires less than 1 mL sample volumes, collected from larger-volume batch cultures at predefined time points for time-course analysis . The electrochemical monitoring of 1,4-BD consumption over nearly 100 h can be correlated with bacterial growth and metabolic activity, assessed in parallel through pH variation and optical density measurements. However, only the electrochemical detection method demonstrates sensitivity at the early stage of culture. The reliable operation of the gold electrodes in complex biological matrices is demonstrated, enabling straightforward tracking of bioconversion processes, providing a scalable and accessible platform for monitoring microbial transformations relevant to plastic bio-upcycling and industrial biotechnology.