Biodegradation of reactive textile dye Novacron Super Black G by free cells of newly isolated Alcaligenes faecalis AZ26 and Bacillus spp obtained from textile effluents

Al Hakim,Md Nizam Uddin,Md Eleus Hussain,Md Zobaidul Hossen,Abul Kalam Azad,Kamrul Islam

doi:10.1016/j.heliyon.2019.e02068

Abstract

Bacteria were isolated from effluents of textile industries and screened by their capability to decolorize at least one of eight reactive dyes used in the textile industries. Three isolates having the capability to decolorize the highest number of dyes with more than 25% of decolorization were identified as Alcaligenes faecalis AZ26, Bacillus cereus AZ27 and Bacillus sp. AZ28 based on morphological, cultural, biochemical characteristics, and 16S rDNA sequence analysis. The decolorization capability of these three bacterial isolates was optimized under different physicochemical conditions by using Novacron Super Black G (NSB-G), one of the eight reactive dyes commonly used in textile industries. These bacterial isolates grew well in the presence of up to 500 mg L−1 of NSB-G and showed decolorization of approximately 90% at 200 mg L−1 of NSB-G after 96 h of cultivation at 37 °C and pH 8.0 under static condition. Decolorization of NSB-G by the bacterial isolates was investigated using UV-VIS spectrophotometry and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The UV-visible absorbance spectra and the FTIR spectrum of the decolorized NSB-G significantly differed from those of the parent dye, indicating that the NSB-G was degraded by the bacterial isolates. High decolorization extent supports the notion that the bacterial isolates reported herein might have potential in the biological treatment of dyeing mill effluents.

Highlights

Textile, pharmaceutical, cosmetic, paper and food industries use synthetic dyes widely (Pandey et al, 2007; Kant, 2012)
To obtain bacterial isolates with a high decolorizing capability, eight textile reactive dyes—namely Novacron Yellow S3R (NY-S3R), Novacron Blue SGL (NB-SGL), Novacron Ruby S3B (NR-S3B), Novacron Navy FNBN (NN-FNBN), Novacron Super Black G (NSB-G), Novacron Turquise HGN (NT-HGN), Novacron Dark Blue WR (NDB-WR), Novacron BR Blue FNG (NBRB-FNG)—were collected from a textile industry located at Kalarpool, Patia, Chittagong, Bangladesh
Morphological, cultural and biochemical characteristics indicated that these fourteen bacterial isolates were distributed among the bacterial genera of Aeromonas (1 isolate), Alcaligenes (1 isolate), Bacillus (4 isolates), Citrobacter (1 isolate), Morganella (1 isolate), Pseudomonas (4 isolates) and Serattia (2 isolates)

Summary

Introduction

Pharmaceutical, cosmetic, paper and food industries use synthetic dyes widely (Pandey et al, 2007; Kant, 2012). About 10,000 different dyes and pigments are used in textile industries and over 7 Â 105 tons are produced worldwide per annum (Aksu and Tezer, 2005; Daneshvar et al, 2007; Celia and Suruthi, 2016). The usage of dyestuff is increasing tremendously due to the rapid increase of industrialization and man's urge for color (Mohan et al, 2002). Due to their wide variety of color shades, high wet fastness profiles, ease of application, brilliant colors and minimal energy consumption, reactive dyes are widely used in the textile industries (Shah et al, 2013). Reactive dyes have high tinctorial value and less than 1 ppm of the dye produces obvious coloration (Gupta et al, 2003)

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Conclusion