Unraveling community adaption and survival strategy of soil microbiome under vanadium stress in nationwide mining environments

<p class="Abstract"><span><span>The vanadium (V) smelters soil harbor wide ranges of microorganisms, whose survival relies on their metabolic activities under stress.</span><span> Nonetheless, the characteristics and functions of soil microbiome in V mining environments have not been recognized at a continental scale. This study investigates microbial diversity, community assembly and metabolic traits of soil microbiome across 90 V smelters in China. A decrease in alpha diversity is observed, along with community variation, which is also jointly explained by other environmental, climatic and geographic factors. Null model shows that V promotes homogeneous selection. V also mediates co-occurrence patterns, with increased positive interspecific associations under higher V concentrations (</span><span>&gt;</span><span>559.6 mg/kg)</span><span>, e.g., <em>f_Gemmatimonadaceae</em>, <em>Nocardioides</em>, <em>Micromonospora</em>, <em>Rubrobacter</em>.</span><span> In addition, 67 metagenome assembled genomes are retrieved via metagenomic analysis. The metabolic pathways of keystone taxa are disentangled to reveal their putative involvement in the V(V) reduction process. Nitrate and nitrite reductase (<em>nirK</em>, <em>narG</em>), and <em>mtrABC</em> are found to be taxonomically affiliated with <em>Micromonospora</em>. sp, <em>FEN-1250</em>. sp, <em>Nocardioides</em>. sp, etc. Additionally, reverse citric acid cycle (rTCA) serves the main carbon fixation pathway, synthetizing alternative energy for putative V reducers, highlighting a synergistic relationship between autotrophic and heterotrophic processes to support the microbial survival. Our findings comprehensively reveal the driving forces for soil community variation under V stress, suggesting the robust strategies adopted by indigenous microorganisms to alleviate V impact, which can be exploited for bioremediation application.</span></span></p>