Phyto-bacterial biosorption of basic fuchsine: A self-sustainable approach towards biomitigation of contaminant of emerging concern

Basic fuchsine dye, a contaminant of emerging concern (CEC) is known for carcinogenicity and mutagenicity on humans and aquatic animals. Environmental persistence of basic fuchsine due to its structural stability is a concern due to its hideous effects on the eco-system. Among various methods of remediation, biological methods of dye adsorption are considered a potential tool and a self-sustainable approach of cleaning contaminated environments. In the current study, a non-pathogenic phyto-symbiotic bacteria, Enterobacter hormaechei subsp. Xiangfangensis strain KG₂16S isolated from Kaempferia pulchra L., was investigated for the reduction of basic fuchsine dye. One factor at a time (OFAT) studies revealed the optimal conditions for remediation was 20 mg/L of dye with 4 g/L of sucrose when introduced with 4 % v/v of the bacteria for 72 h. Adsorption kinetics demonstrated the biosorption design followed pseudo-first-order (PFO) kinetics as the R²value is 0.93, while the adsorption isotherms obey the Langmuir isotherm (R²value is 0.975). Analytical techniques like LCMS and FTIR analysis of bacterial biomass revealed the dye adsorption onto the bacterial surface. SEM-EDS analysis indicated the presence of Sodium (Na) and Chlorine (Cl) on the bacterial surface. Florescent microscopy of bacteria indicated duration-based dye accumulation and dye internalization and hence the current study is the first to report this phenomenon of biomitigation. In-silico toxicity assay predicted the dye as a probable causative agent of developmental toxicity. Cytogenotoxicity assay indicated reduced toxicity in comparison to the untreated sample. Through this study, we propose phyto-bacterial biosorption as a self-sustainable, eco-friendly approach to reduce the hideous effects on plants, humans, and the environment caused by the bioaccumulation of these carcinogenic dyes.