Comparative study on Cronobacter sakazakii and Pseudomonas otitidis isolated from septic tank wastewater in microbial fuel cell for bioelectricity generation

Abstract

The potential of microbial isolates from septic tank wastewater to generate bioelectricity in microbial fuel cell was investigated. The isolates were identified as Cronobacter sakazakii AATB3 and Pseudomonas otitidis AATB4. The sterilized septic tank wastewater alone was used as an organic matter to study the exact role of the isolates in bioelectricity production and biodegradation of septic tank wastewater. P. otitidis AATB4 achieved the highest bioenergy generation (i.e., power density of 280 mW/m2 and current density of 800 mA/m2), highest COD removal (i.e., 79.1%), and maximum coulombic efficiency of 15.5% at pH 7. The biofilm of P. otitidis AATB4 at the anodic surface contained 49 µg/cm2 of protein and 57 µg/cm2 of carbohydrate. Scanning electron microscope and confocal laser scanning microscope revealed 46 µm biofilm thickness by P. otitidis AATB4 in the electrode for stable power generation. It is concluded that P. otitidis AATB4 can be used as a novel bioelectrogen in microbial fuel cell for sustainable energy production using septic tank wastewater.