Mycoremediation of reactive red HE7B dye by Aspergillus salinarus isolated from textile effluents.

Reactive dyes are widely utilized in the textile industry due to their advantageous properties of vivid color, water-fastness, and simple application procedures with minimal energy usage. The toxicity of most azo dyes is a significant environmental concern, as effluents from dye processing and manufacturing sectors are known to be carcinogenic and mutagenic to numerous species. These issues are more grievous in Bangladesh, one of the largest exporters of apparel. This study aimed to isolate and identify potential fungal strains from textile effluent that are capable of degrading Reactive Red HE7B dye (a sulphonated reactive azo dye), a widely used dye in local thread dyeing industries. Dye degradation assay was performed in potato dextrose broth supplemented with 50 mg/l Reactive Red HE7B and the degradation rate was measured by a UV spectrophotometer. DNA extraction, quantification, PCR, internal transcribed spacer (ITS) sequencing, and phylogenetic analysis were performed to identify the selected fungi. Among the isolates, the three best performing strains TEF -3, TEF -4, and TEF -5 showed 97.41%, 93.12%, and 82.89% dye degrading efficacy after 96 h of incubation, respectively. All three strains, TEF-3, TEF-4, and TEF-5 showed similarity with Aspergillus salinarus (accession no. NR_157473.1) and the similarity percentages were 97.02, 96.95, and 95.28 respectively. Interestingly, this study probably the very first indication of textile dye degradation by Aspergillus salinarus strains. Thus, these fungal strains possess the prospectiveness to be utilized in the textile wastewater treatment plants, since the isolates demonstrated the substantial capacity (>80%) to degrade Reactive Red dye after 96 h of incubation.

Bioremediation of malachite green dye by two bacterial strains isolated from textile effluents.

Globally, water pollution from the textile industries is an alarming issue. Malachite Green dye of the triphenylmethane group is an extensively used dye in the fabric industries that is emitted through textile wastewater. This study aimed to isolate and characterize potential Malachite Green (MG) dye degrading bacteria from textile effluents. Different growth and culture parameters such as temperature, pH and dye concentration were optimized to perform the dye-degradation assay using different concentrations of MG dye in the mineral salt medium. A photo-electric-colorimeter was used to measure the decolorizing activity of bacteria at different time intervals after aerobic incubation. Two potential bacterial strains of Enterobacter spp. CV-S1 (accession no: MH450229) and Enterobacter spp. CM-S1 (accession no: MH447289) were isolated from textile effluents exhibiting potential MG dye decoloring efficiency. Further, the RAPD analysis and 16S rRNA sequencing confirmed the genetic differences of the isolated strains. Enterobacter sp CV-S1 and Enterobacter sp CM-S1 can completely decolor MG dye up to 15 mg/L under shaking condition without any requirement of sole carbon source. Thus, these two bacteria have the potency to be utilized in the textile wastewater treatment plant.