Community diversity metrics, interactions, and metabolic functions of bacteria associated with municipal solid waste landfills at different maturation stages

Abstract

Municipal landfills are hot spots of dynamic bioprocesses facilitated by complex interactions of a multifaceted microbiome, whose functioning in municipal landfills at different maturing stages is poorly understood. This study determined bacterial community composition, interaction conetworks, metabolic functions, and controlling physicochemical properties in two landfills aged 14 and 36 years. High throughput sequencing revealed a similar distribution of bacterial diversity, evenness, and richness in the 14‐ and 36‐year‐old landfills in the 0–90 cm depth. At deeper layers (120–150 cm), the 14‐year‐old landfill had significantly greater bacterial diversity and richness indicating that it is a more active microcosm than the 36‐year‐old landfill, where phylum Epsilonbacteraeota was overwhelmingly dominant. The taxonomic and functional diversity in the 14‐year‐old landfill was further reflected by the abundant presence of indicator genera Pseudomonas,Lutispora,Hydrogenspora, and Sulfurimonas coupled with the presence of biomarker enzymes associated with carbon (C), nitrogen (N), and sulfur (S) metabolism. Furthermore, canonical correspondence analysis revealed that bacteria in the 14‐year‐old landfill were positively correlated with high C, N, S, and phosphorus resulting in positive cooccurrence interactions. In the 36‐year‐old landfill, negative coexclusion interactions populated by members of N fixing Rhizobiales were dominant, with metabolic functions and biomarker enzymes predicting significant N fixation that, as indicated by interaction network, potentially inhibited ammonia‐intolerant bacteria. Overall, our findings show that diverse bacterial community in the 14‐year‐old landfill was dominated by copiotrophs associated with positive conetworks, whereas the 36‐year‐old landfill was dominated by lithotrophs linked to coexclusion interactions that greatly reduced bacterial diversity and richness.

Toxicity effects of aged refuse on Tagetes patula and rhizosphere microbes

“…Consistent with the findings of recent studies, we established that the microbial alpha diversity index of aged refuse from mature landfill was relatively lower than that of normal soil (Sekhohola Dlamini et al, 2021;B. Yadav et al, 2020).…”

Local Geomorphological Gradients and Land Use Patterns Play Key Role on the Soil Bacterial Community Diversity and Dynamics in the Highly Endemic Indigenous Afrotemperate Coastal Scarp Forest Biome

“…The other soil subset was air-dried, milled and sieved through a 2-mm mesh for soil geochemical analysis. Soil geochemical factors, including pH, electrical conductivity (EC), water content, total carbon (TC), soil organic matter (SOM), total nitrogen (TN), and metals (Al, Ca, Fe, K, Mg, Na, and Zn), were quantitatively measured as previously described by Sekhohola-Dlamini et al (2020).…”

Changes in the bacterial rare biosphere after permanent application of composted tannery sludge in a tropical soil

“…Some well-known bacterial phyla, i.e., Proteobacteria, and Actinobacteria, were found abundantly in both rare and dominant biosphere. It is expected since these phyla are usually found in soils with the application of solid wastes with high organic matter content (Zhang et al, 2018;Sekhohola-Dlamini et al, 2021), such as composted tannery sludge. However, Chloroflexi and Planctomycetes were found abundantly in the rare biosphere, suggesting a change in the bacterial composition.…”