Effects of biopolymers, cork, and Rhizobium tropici-derived extracellular polymeric substances on soil microbial communities

Amplicon sequencing of the 16S rRNA gene identified 62,996 amplicon sequence variants (ASVs), with 513 ASVs shared across all time points and 467 ASVs shared among the different treatments. The microbial community was primarily composed of <i>Actinobacteria, Proteobacteria</i>, and <i>Acidobacteria</i>, with <i>Actinobacteria</i> being the most abundant phylum. <i>Actinobacteria, Alphaproteobacteria, Bacilli</i>, and <i>Betaproteobacteria</i> contributed to microbial diversity at the class level. Notable families such as <i>Bacillaceae, Gaiellaceae, Micromonosporaceae</i>, and <i>Streptomycetaceae</i> showed treatment-dependent variations. Core microbiome analysis revealed <i>Bacillus</i> and <i>Gaiella</i> as the dominant genera, which play vital roles in soil ecosystem stability and nutrient cycling. These microbes contribute to carbon sequestration, nitrogen fixation, and phosphorus solubilization, improving soil fertility and plant-microbe interactions. These findings offer valuable insights into microbial dynamics in amended soils, providing information that can improve soil quality and agricultural productivity.