Bioelectrochemical detoxification of phenolic compounds during enzymatic pre-treatment of rice straw.

The use of lignocellulosic biomass such as rice straw can subsidize the economical operative cost in the production of value-added chemicals. However, inhibitory compounds, such as phenolics, produced during the pre-treatment of biomass, hamper the saccharification process. Laccase and electrochemical stimulus are both well known to reduce phenolic compounds. Therefore, in this study, we implemented a bioelectrochemical detoxification system (BEDS), a consolidated electrochemical and enzymatic process involving laccase, to enhance detoxification from phenolics, and thus achieve a higher saccharification efficiency. Saccharification of pretreated rice straw using BEDS at 1.5 V showed 90% phenolic reduction (Phr), thereby resulting in a maximum saccharification yield of 85%. In addition, the specific power consumption by BEDS (2.2 W/Kg Phr) was noted to be 24% lower than by the electrochemical process alone (2.89 W/kg Phr). To the best of our knowledge, this is the first study to implement BEDS for reduction of phenolic compounds in pretreated biomass.