Biodegradation of Textile Wastewater by Naturally Attenuated Enterobacter sp.

The exponential increase in anthropogenic activities has led to the accumulation of xenobiotics into the environment, synthetic dyes being one of the culprits. Noteworthy is the fact that the textile industry utilizes enormous volumes of water for dyeing and printing unit operations thereby generating wastewater proportionately. Taking into consideration, implications of toxic textile effluents, a pilot study was planned to screen for naturally attenuated bacterial isolates capable of degrading textile effluents. Requisite effluent samples were collected from Kelki Printers Co-operative Society Limited, Sanganer, Jaipur and bacterial screening was carried out by bioaccumulation of Remazol Brilliant Blue R (RBRR) (formation of halo around colonies). Of the 19 bacterial isolates obtained, the most promiscuous isolate was biochemically characterized as Enterobacter sp. For biodegradative investigations, it was inoculated in sterilized textile effluent and incubated at 37°C for 7 days under agitating conditions. Pre and post bacterial inoculation (1% v/v), Physico-chemical parameters were analysed following standard procedures. A significant (p<0.05) lowering of pollution indicators was monitored when contrasted with abiotic control. The present study was aimed to explore the role of naturally attenuated and effluent adapted Enterobacter sp. screened from untreated textile effluent based on its colour (RBRR) removal efficacy under in vitro conditions. Furthermore, it was also explored for its biodegradative properties to minimize the level of potential pollution indicators through the microcosm approach. This pilot study based on a three-tier approach encompassing bioprospecting, bio enrichment and bioaugmentation plausibly provided insights for enhanced degradation of real dye wastewaters by unlocking the biochemical pathways of adapted microbes. INTRODUCTION Attainment of Sustainable Development Goals (SDGs) has become questionable in the current scenario, taking into account the ever-increasing concerns of environmental pollution. Industrial practices have contributed to socio-economic development but lack of sustained industrial practices aggravates bioaccumulation and persistence of toxicants. Synthetic dyes are extensively used by textile industries leading to the generation of enormous volumes of coloured effluents post dyeing and printing process (Sharma et al. 2019). Besides synthetic dyes, effluents are composed of heavy metals, bleaching agents, surfactants and other recalcitrant compounds (Mondal et al. 2017). Mainstream investigations have focused upon evaluation of physico-chemical profile of textile effluents and their potential toxicological implications (Bhatia et al. 2018). Catering to address toxicity hazards generated by textile effluents, biological interventions utilizing the role of indigenous microbes for biodegradation have been investigated in recent past (Chanwala et al. 2019, Vikrant et al. 2018). Majorly, bacteria have been explored for their metabolic potential to degrade synthetic dyes, heavy metals and chemical surfactants from dye house effluents. Different mechanisms have been explored for microbial mediated dye removal like biosorption (Solis et al. 2012), biodegradation by catalytic enzymes like azoreductase (Ehlfarash et al. 2017), laccase (Mirzadeh et al. 2014), peroxidase (Saroj et al. 2014). Considering the above-cited facts, we proposed an in situ bioremediation study wherein, the role of microbes native to dye house effluent was explored to biodegrade textile effluent based on its dye removal efficacy in synthetic medium. MATERIALS AND METHODS Study Area: Sanganer town with co-ordinates (26°49¢ to 26°51¢N latitude and 75°46¢ to 75°51¢ longitude) is located within outskirts of Jaipur, famous for its ethnic hues, handNat. Env. & Poll. Tech. Website: www.neptjournal. com Received: 06-08-2019 Accepted: 29-08-2019