Performance evaluation of isolated electrogenic microalga coupled with graphene oxide for decolorization of textile dye wastewater and subsequent lipid production

Microalgae are photosynthetically competent organisms that utilize solar energy to perform several metabolic activities. In this study, electrogenic microalga Desmodesmus sp. was isolated from discharge site of textile dyeing mill effluent and was explored for its potential for dye degradation and lipid production. Extracellular electron transfer (EET) by microbes displays their capability to associate with its surrounding environment. To attain an efficient alternative, a nanobiotechnological approach was applied, wherein; extracellular electrons of Desmodesmus sp. was coupled with graphene oxide (GO) nanosheets on its electron-rich draper region to form a GO/algae bionanocomposite. Electrochemical tests of the bionanocomposite revealed that amalgamation of GO sheets with Desmodesmus sp. enhanced its electron availability (redox potential) without affecting its viability, demonstrating a sustainable and efficient reduction of azo dye along with enhanced lipid production to be used for biodiesel generation. The current bionanocomposite, thus, offers an eco-friendly, reusable, economical and sustainable solution towards water remediation and subsequent biofuel production.