Microaerophilic biodegradation of raw textile effluent by synergistic activity of bacterial community DR4

Rohit Rathour; Kunal Jain; Datta Madamwar; Chirayu Desai

doi:10.1016/j.jenvman.2019.109549

Microaerophilic biodegradation of raw textile effluent by synergistic activity of bacterial community DR4

J Environ Manage. 2019 Nov 15:250:109549. doi: 10.1016/j.jenvman.2019.109549. Epub 2019 Sep 17.

Authors

Rohit Rathour¹, Kunal Jain², Datta Madamwar², Chirayu Desai³

Affiliations

¹ P. D. Patel Institute of Applied Sciences, Charotar University of Science and Technology (CHARUSAT), CHARUSAT Campus, Changa, 388 421, Gujarat, India. Electronic address: rohitrrathour1918@gmail.com.
² Environmental Genomics and Proteomics Lab, Post Graduate Department of Biosciences, UGC Center of Advanced Study, Sardar Patel University, Satellite Campus, Vadtal Road, Bakrol, 388 315, Anand, Gujarat, India.
³ P. D. Patel Institute of Applied Sciences, Charotar University of Science and Technology (CHARUSAT), CHARUSAT Campus, Changa, 388 421, Gujarat, India. Electronic address: chirayudesai.bt@charusat.ac.in.

PMID: 31545178
DOI: 10.1016/j.jenvman.2019.109549

Abstract

Treatment of raw textile effluent (RTE) is very difficult, due to its inherent heterogeneous, low-biodegradable and toxic compositions. Pure and mixed microbial cultures have limited metabolic capabilities in effective mineralization of complex RTE. Therefore, in this study a novel bacterial community DR4 was enriched directly into a complex RTE consisting of 27 different dyes using textile dye polluted soil as an inoculum. The rigorous enrichment process resulted in acclimatization of a taxonomically distinct bacterial population, with an abundance of the genus Comamonas in the bacterial community DR4 as compared to the abundance of Pseudomonas in the RTE respectively, as revealed by high-throughput 16S rRNA gene (V3-V4 region) sequencing. Microaerophilic treatment of RTE by enriched bacterial community DR4, in the presence of optimized electron donor (sucrose) and nitrogen source (yeast extract) resulted in 88% of American Dye Manufacturer's Institute (ADMI) removal and 98% of Chemical oxygen demand (COD) reduction within 32 h at 37 °C. In silico prediction of the functional genes within bacterial community DR4 was made by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis. The PICRUSt analysis revealed high abundance of xenobiotic degradation and metabolism genes. The predicted functional genes and textile dye degradation pathways were further validated using Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR) spectroscopy and High Resolution Liquid Chromatography coupled with Mass Spectrometry (HR-LCMS) based characterization of textile dye degradation metabolites. The activity of azoreductases in the cell-free extracts (CFE) of the enriched bacterial community DR4 was induced by 1.83-7.81 folds in the presence of representative textile dyes as compared to uninduced samples, which confirmed their role in textile effluent decolourization. The degradation of four representative azo dyes present in RTE such as Disperse orange 30, Reactive red 152, Direct blue 2 and Acid brown 15 depicted symmetric degradation of azo bonds by bacterial community DR4.

Keywords: Azo dyes; Comamonas; Microcosms; Raw textile effluent.

MeSH terms

Azo Compounds
Biodegradation, Environmental
Coloring Agents
Phylogeny
RNA, Ribosomal, 16S
Spectroscopy, Fourier Transform Infrared
Textile Industry*
Textiles*

Substances

Azo Compounds
Coloring Agents
RNA, Ribosomal, 16S