Molecular assessment of shift in bacterial community in response to Congo red

Pollutants are known to have significant impact on bacterial community. In present study, influence of diazo dye, Congo red on soil bacterial population was monitored. Molecular analysis of shift in community after different time intervals was monitored by using PCR–DGGE targeting V3 region of bacterial 16S rRNA gene. UPGMA was performed to determine coherence in community structure at different time intervals. Natural microbial community from dye contaminated site belonged to alpha, gamma proteobacteria, Sphingobacteria and some uncultured bacteria. Significant shift in bacterial population was observed upon Congo red exposure. Presence of number of uncultured bacteria indicates their sustainability in dye environment and involvement in dye degradation.

► Metagenomic approach for studying bacterial population from dye contaminated site.
► First report on tolerance of bacterial community for hazardous, complex diazo dye.
► Employed nested PCR–DGGE strategy is suitable to predict shift in bacterial population.
► Optimized silver staining protocol is ideal for denaturating polyacrylamide gels.