Do waste management practices affect the internal microbiome dynamics? Let's dig inside

Municipal solid waste (MSW) disposal sites are hubs of dynamic bioprocesses supported by intricate interactions of a diverse microbiome, the role of which is poorly known at MSW disposal sites at varying ages. This study determined bacterial diversity composition and physico–chemical properties in two dumping sites aged NDS and ODS. Both the ODS and NDS have comparable bacterial richness and diversity, as determined by high throughput metagenomic amplicon sequencing. The ODS had significantly greater bacterial diversity and richness, than the NDS, where phylum Proteobacteria (31.61 %) was overwhelmingly dominant followed by Bacteroidota (11.06 %), Acidobacteriota (8.69 %), Actinobacteriota (8.30 %), and Planctomycetota (8.25 %). The abundant presence of indicator pathogenic genera Nocardia, Bacillus, Achromobacter, Enterobacter, Rhodococcus, Escherichia, etc. further reflected the taxonomic and functional diversity in the dumping site. Finally, redundancy analysis (RDA) (non–symmetric levels) was done to evaluate the relationship between the dominant genus communities (such as Marmoricola, Muricauda, Stenotrophobacter, Arenimonas, Acinetobacter, Truepera, and Thermomonas) and biochemical parameters (such as Mn, Zn, Cu, K₂O, organic carbon, nitrogen content, and electric conductivity), resulting in a negative correlating interaction. These findings will help to understand the bacterial diversity and its potential risk of contamination in formal and informal dumping sites with different dump age groups. Hence, it highlighted a significant knowledge gap about the environmental consequences of open dumping sites and will help in the development of disease prevention strategies and sustainable waste management.