Wastewater bioremediation potential

The textile industry is one of the major contributors to environmental pollution around the world [1]. The different stages of fabric processing require the use of large amounts of water to which are added various harmful chemicals. The dying process, during which colour is added to the fabric, results in the production of wastewater containing heavy metals, salts, surfactants, dyes, and high biochemical oxygen demand (BOD) levels [1]. Failure to treat the wastewater for the removal of toxic chemicals and metals has been documented for many textile processing facilities around the world [2], and has resulted in the contamination of soils, bodies of water, and other habitats in proximity to these facilities. Bioremediation of organic dyes and wastewater pollutants is an environmentally sustainable strategy for treatment prior to discharge. However, issues with cost, scalability, and the variable chemical content of textile wastewater have prevented widespread application [3]. Therefore, the search for novel microbial organisms or consortia capable of degrading a wide range of harmful chemicals is of great interest. In this study, we analysed the chemistry of an effluent obtained from a UK-based textile company, and enriched microbial strains for their bioremediation potential. Chemical analysis identified high concentrations of toxic trace metals (Zn, Fe, Ni) in the effluent. Microorganisms were successfully enriched on aerobic and anaerobic media, resulting in the isolation of 27 isolates spanning the Actinomycetota, Pseudomonadota, Bacillota, Thermodesulfobacteriota, and Bacteroidota phyla. The ability of these isolates to improve the colouration of the effluent were tested under incubation at 30°C. Nine representative isolates were chosen for genome sequencing, and their genomes were screened for pathways involved in the degradation of commonly used dyes (e.g., azo dyes) and the utilisation of trace metals. References: [1] Madhav S, Ahamad A, Singh P, Mishra PK. A review of textile industry: Wet processing, environmental impacts, and effluent treatment methods. Environ Qual Manage. 2018; 27: 31–41. https://doi-org.libezproxy.open.ac.uk/10.1002/tqem.21538 [2] Yaseen, DA, Scholz, M. Textile dye wastewater characteristics and constituents of synthetic effluents: a critical review. Int. J. Environ. Sci. Technol. 2019; 16: 1193–1226. https://doi.org/10.1007/s13762-018-2130-z [3] Ceretta MB, Nercessian D and Wolski EA. Current Trends on Role of Biological Treatment in Integrated Treatment Technologies of Textile Wastewater. Front. Microbiol. 2021; 12:651025. https://doi.org/10.3389/fmicb.2021.651025