Modification of bacterial cell membrane to accelerate decolorization of textile wastewater effluent using microbial fuel cells: role of gamma radiation

Abstract

The aim of the present work was to increase bacterial adhesion on anode via inducing membrane modifications to enhance textile wastewater treatment in Microbial Fuel Cell (MFC). Real textile wastewater was used in mediator-less MFCs for bacterial enrichment. The enriched bacteria were pre-treated by exposure to 1 KGy gamma radiation and were tested in MFC setup. Bacterial cell membrane permeability and cell membrane charges were measured using noninvasive dielectric spectroscopy measurements. The results show that pre-treatment using gamma radiation resulted in biofilm formation and increased cell permeability and exopolysaccharide production; this was reflected in both MFC performance (average voltage 554.67 mV) and decolorization (96.42%) as compared to 392.77 mV and 60.76% decolorization for non-treated cells. At the end of MFC operation, cytotoxicity test was performed for treated wastewater using a dermal cell line, the results obtained show a decrease in toxicity from 24.8 to 0 (v/v%) when cells were exposed to gamma radiation. Fourier-transform infrared (FTIR) spectroscopy showed an increase in exopolysaccharides in bacterial consortium exposed to increasing doses of gamma radiation suggesting that gamma radiation increased exopolysaccharide production, providing transient media for electron transfer and contributing to accelerating MFC performance. Modification of bacterial membrane prior to MFC operation can be considered highly effective as a pre-treatment tool that accelerates MFC performance.

Valorization of frying oil waste for biodetergent production using Serratia marcescens N2 and gamma irradiation assisted biorecovery

“…Screening of biosurfactant production using different S. marcescens strains was performed as an initial step. S. marcescens N2 with the highest production was identified as prodigiosin hyper producing strain in a previous study [ 16 ]. Variation between S. marcescens isolates could be intrinsic within every strain capable of biosurfactant production.…”

Valorization of Oil Waste for Biodetergent Production Using Serratia Marcescens N2 and Gamma Irradiation Assisted Biorecovery

“…In a previous study, 1000 Gy was enough to induce permeability of Bacillus sp. producing biosurfactant (Selim et al, 2020) their results showed that this dose is enough to induce changes without compromising the bacterial viability. The obtained results con rm that low dose gamma radiation can be used for enhancing biorecovery without affecting biosurfactant structure and characteristics.…”

“…From this stand point; gamma radiation can be considered an effective tool for release of biosurfactant from bacterial cells. Gamma radiation was previously used to permeabilize the cell wall of gram positive bacteria to help release biomolecules to the media (Selim et al, 2020).…”