BIOREMEDIATION OF CHROMIUM (VI) BY A MICROBIAL CONSORTIUM ISOLATED FROM TANNERY EFFLUENTS AND THEIR POTENTIAL INDUSTRIAL APPLICATION

Arghyadeep Bhattacharjee,Arup Kumar Mitra,Priyanshu Pandey,Rajarshi Chaudhuri

doi:10.3846/jeelm.2021.15762

Abstract

West Bengal has several leather industries and as such huge amount of leather are processed every year. The tannery effluents are discharged into the land and open water causing soil and water pollution respectively. Chromium is one of the most toxic inorganic contaminants which is well known for its carcinogenicity. Thus, our study focuses on investigating the bioremediation potential of common microflora isolated from tannery wastewater. In our study, Isolate 1 has the highest ability to reduce chromium (Cr6+) as compared to others. Isolate 4 has the highest protease, lipase and leather degradation activities. Isolate 1 shows the maximum keratinase activity making it an effective strain for keratinase production. Also, it has been found that pH 8 and temperature 40 °C was most suitable for keratinase production. Owing to the multidimensional ability of these two isolates, they were identified by 16S rRNA sequencing and it reveals that Isolate 1 and Isolate 4 belong to Bacillus cereus F4810/72 and Brevibacillus brevis F4810/72 respectively. Thus, this study establishes the role and efficiencies of these microorganisms in combatting pollution, particularly in the water bodies in which harmful chemicals leak regularly owing to improper waste management by various industries.

Highlights

Air-water-land, the three essential components of the environment is being rapidly contaminated gradually owing to rapid urbanization, a massive increase in population density, and developing industrialization (Saranraj &Sujitha, 2013)
The Tannery industry is considered to be a major source of pollution and tannery wastewater has become a potential environmental concern nowadays as it contains significant concentrations of toxic inorganic contaminants like chromium, dissolved organic matter, and salts (Sharma & Malaviya, 2014; Bharagava et al, 2018)
The selected isolates were designated as Isolate 1 (IS1) – Isolate 4 (IS4)

Summary

Introduction

Air-water-land, the three essential components of the environment is being rapidly contaminated gradually owing to rapid urbanization, a massive increase in population density, and developing industrialization (Saranraj &Sujitha, 2013). When the toxic contaminants mobilize into the environment, they tend to persist, circulate, and accumulate in different levels of the. Chromium is a refractory metal that mainly exhibits two inorganic states namely trivalent Cr (III)) and hexavalent Cr (VI)) These are considered the most stable oxidation states found in the environment that differ greatly in physical, chemical and biological activities (Sanjay et al, 2020). Plants exposed to environmental chromium cause oxidative metabolic stress (Srinath et al, 2001) that leads to the production of active free radicals Such active radicals play a crucial role in modulating various signal transduction pathways that lead to the distortion of cellular membranes and organelles in plants (Oliveira, 2012)

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Discussion

Conclusion