Enzymatic Degradation of Azo Bonds and Other Functional Groups on Commercial Silk Dyes by Streptomyces coelicoflavus CS-29

Abstract

Azo dyes are used for silk textile manufacture, where their decolorization and detoxication are necessary after initial dying in the craft industry. The bio-decolorization efficiency of Streptomyces coelicoflavus CS-29 toward commercial azo blue and red dyes was investigated, analyzing the degradation and adsorption of dye molecules. S. coelicoflavus CS-29 showed reductions of 70% and 51% in red and blue dyes, respectively, after seven days. Morphological observation by light microscopy showed that dye molecules were adsorbed onto S. coelicoflavus CS-29 cell surface to form a dense cell pellet. Moreover, peroxidase and laccase activity were detected as extracellular enzymes, but no azo-reductase was detected. From the enzymatic activity, changes of dye profiles in HPLC showed differences between control dyes (untreated dyes) and metabolized products of dyes treated with S. coelicoflavus CS-29. The presence of main functional azo groups (-N=N-) in both blue and red silk dyes was indicated by FTIR analysis, in the untreated azo dyes. The azo bonds seemed to disappear in metabolites after S. coelicoflavus CS-29 treatment and other functional groups were changed compared to the control dyes. The treated dyes showed no significant effect on seed germination, root length, and shoot length of mung beans during phytotoxicity analysis. The red dyes showed a more negative effect on shoot lengths than the blue dyes. The overall results showed that S. coelicoflavus CS-29 is an effective and promising tool for the treatment of dye contaminated wastewater and the permanent elimination of recalcitrant commercial azo dye pollutants.

Whole Genome Analysis of Streptomyces spp. Strains Isolated from the Rhizosphere of Vitis vinifera L. Reveals Their Role in Nitrogen and Phosphorus Metabolism

“…Existing studies have instead focused on investigating their microbial capabilities in biocontrol through the production of secondary metabolites. For example, S. coelicoflavus has been utilized as a biological control agent [44], demonstrating its ability to inhibit quorum sensing [45] and produce extracellular enzymes such as peroxidase, laccase [46], and cellulases [47]. On the other hand, biosynthetic genes have been identified in the genome of S. achromogenes [48], some of which have been reported as potential sources of bioactive metabolites with antioxidant and anticancer activities [49].…”

Color Adsorption Performance of Bone Biocomponent for Textile Dyeing Effluent Treatment in Ethiopia

“…Te physicochemical methods such as photocatalysis [15], focculation/coagulation [16][17][18], sonication, sludge adsorption [19], ion exchange [20,21], activated carbon adsorption [22][23][24], ozonation [25,26], irradiation, and electrochemical oxidation [27,28] were well studied for small scale industries. Te biological approaches [29][30][31][32] of treatment using fungi [33], algae, yeast, bacteria, plants [34][35][36], and animal [37] wastes were considered as costefective, sustainable, and environmentally benefcial approach [38][39][40] while being specifc in use. Among animal wastes, bovine bones were abundantly available wastes which creates nonhealthy environment [41] and also increases with the increase of meat consumption [42].…”