Rapid Protocol for Screening of Biocatalyst for Application in Microbial Fuel Cell: A Study with Shewanella algae

Due to energy expansion and sustainable development of resources and systems, there has been an increasing demand for environmentally friendly alternative energy systems. Microbial fuel cells (MFCs) are considered one of the most promising alternative energy generation systems. The microorganism is one of the key limiting factors to enhance the performance efficiency of MFC. Therefore, proper evaluation of screening protocol is imperative benchmarks for selection of biocatalyst in MFC. In the present study, an attempt was taken for rapid evaluation of iron-reduction capacity and growth of Shewanella algae through optimization of process parameters using Taguchi methodology. Here, five process parameters, including lactose, trace element, inoculum percentage, pH, and temperature, were taken into consideration as imperative factors and were optimized for evaluation of iron-reduction analysis along with growth of bacteria. The main effect of each parameter, along with their interaction influence and optimal value, was determined using a signal-to-noise (S/N) ratio. The evaluation of quality characteristics of each parameter was also determined in Taguchi robust methodology using S/N ratio. Analysis of variance was performed to assess statistically important process parameters. Predicted results exhibited that enhanced bacterial growth (120%) and iron-reduction capacity (114%) can be achieved with 8 g/L of lactose, 2 mL of trace element solution, 7 of initial pH, 30 °C of temperature, and 4% (v/v) of inoculum percentage. It is evident from the results that Shewanella algae can be used as a promising catalyst for MFC.