Insight into biosorption of hexavalent chromium using isolated species Aspergillus Proliferans LA: A systemic and In silico studies

Background: The wastewater disposal into the water bodies without removing the toxic heavy metals and other industrial impurities is a major issue these days. These heavy metals cause serious health issues to the human and animal life and also harm the environment and reduce the productivity of crops. A potent microorganism resistant to hexavalent chromium was isolated. The activity of this isolated strain was analyzed using in silico studies. Methods: In this study, a chromium-resistant fungus was isolated from the soil of the dumping sites of the tanneries in Kanpur, UP, India, followed by isolation by serial dilution, plating method, and finally, genome sequencing. It was identified as Aspergillus proliferans LA that is submitted to the National Collection for Industrial Microorganisms (NCIM) database with accession no. NCIM-1473. In the current study, the comparative analysis of the protein sequence of A. proliferans (NCIM-1473) was done against the known 53 protein sequences of the fungus and bacterial strains already reported for their chromium-resistant nature. The physical and chemical parameters of the known and isolated chromium-resistant proteins were analyzed using the ProtParam tool. The comparative study on the sequence and structural alignment of known and isolated chromium-resistant protein was done using EMBOSS-NEEDLE and FATCAT, respectively. Results: In this analysis, the top 10 strains showing similarity with A. proliferans (NCIM-1473) were reported and among which ChrI, chromium regulatory protein Cupriavidus metallidurans CH34 was showing maximum similarity with isolated chromium resistant protein for all the analysis, namely ProtParam, sequence, and FATCAT analysis. This strain, Cupriavidus metallidurans CH34, has been reported resistant against eight heavy metals, one of which is chromate, and was first identified in the heavy-metal contaminated sludge in a settling tank of Belgium. Conclusion: These studies conclude that the strain isolated in our laboratory (accession no. NCIM-1473) is potentially chromium resistant and a unique strain.