Harnessing the bioremediation potential of indigenous Pseudomonas stutzeri for textile effluent treatment: a mechanistic insight.

Textile industrial effluent is a significant source of environmental pollution, posing serious risks to human health and ecosystem. Also, textile industry is a major consumer of water, a finite and critical natural resource thereby further aggravating environmental challenges. Current effluent treatment methodologies predominantly rely on chemical processes, which are often hazardous and generate copious amount of sludge as secondary waste which eventually contaminate environment. While microbial bioremediation has been explored in previous studies, these efforts have been largely restricted to laboratory-scale applications, with limited success at industrial-scale implementation. This study focuses on the isolation and characterization of an indigenous bacterial strain, Pseudomonas stutzeri, from textile industries, followed by its optimization for enhanced efficacy. Optimization experiments were conducted to evaluate the effects of key physicochemical parameters, including pH, temperature, carbon, and nitrogen sources, on the strain's performance under in vitro conditions. Proteomic analysis of Pseudomonas stutzeri under control and effluent-stressed conditions revealed differential protein expression, elucidating the molecular mechanisms underlying its response to stressful conditions. The optimized strain was employed for the treatment of the textile effluent at laboratory scale, followed by industrial-scale trials across multiple sites in Rajasthan, India. Effluent samples collected from in vitro and industrial trials were analyzed using high throughput analysis (UV-Vis and AAS). Comparative analysis indicated that the industrial-scale application achieved significantly higher rates of decolorization, degradation, detoxification and mitigation of hazardous components, including dyes, chemicals, and heavy metal contaminants, compared to laboratory-scale experiments. After on-site industrial trials, the pre- and post-treated effluent was analyzed using FT-IR and GC-MS. The observations from the study provided insights into the functional group transformations and identified degraded metabolites, confirming the biodegradation potential of the screened isolate. This study highlights the untapped potential of Pseudomonas stutzeri as a robust and scalable technology for the bioremediation of dye/chemical/heavy metal loaded textile effluents at industrial scale, hence can be used to promote sustainable development by water upcycling.