A Newly Isolated Stress-Resistant Bacterial Strain with Potential Use in Bioremediation of Dyeing Effluents

The issue of water pollution is one of the hot topics of global concern, which requires us to efficiently treat pollutants in water, especially printing and dyeing sewage. There are varieties of dyestuffs and intermediates, which are complex and difficult to degrade, and they even contain heavy metals. In this study, a bacterial strain named Q3-6 with potential for sewage treatment was isolated and its physiological, biochemical, and genomic characteristics, and potential application value, were further investigated. The genome sequence confirmed that it belongs to Bacillus thuringiensis. Strain Q3-6 has a significant decolorization effect on the dyes. The decolorization rate for Brilliant blue G-250 (0.1 g/L) and Congo Red (0.1 g/L) can reach 93.9% and 91.9%, respectively. In addition, strain Q3-6 is resistant to many kinds of antibiotics and heavy metals. Further, it has strong heat resistance, and heating at 80 °C can promote the biomass of the strain. Genomic analysis revealed the presence of genes related to heat shock proteins (GroES, GrpE, DnaJ, GroEL, DnaK, ClpB, and ClpA) in strain Q3-6. These results suggest the strain’s exceptional resilience and adaptability to intricate environments with heavy metals, antibiotics, or high-temperature environments, suggesting its pivotal role in the bioremediation of complex contaminated effluents.