Metagenomic analysis revealed the bioremediation mechanism of lead and cadmium contamination by modified biochar synergized with Bacillus cereus PSB-2 in phosphate mining wasteland

The results indicated that the available phosphate content in the soil increased by 59.32%. The content of extractable state Pb^{2 +} and Cd^{2 +} decreased by 65.06 and 71.26%, respectively. And the soil nutrient conditions were significantly improved. Synergistic remediation can significantly increase the diversity and abundance of soil microbial communities (<i>p</i> < 0.05). <i>Janibacter</i>, <i>Lysobacter</i>, <i>Ornithinimicrobium</i>, <i>Bacillus</i>, and <i>Salinimicrobium</i> were the main functional flora during soil remediation, with significant correlations for the promotion of Pb^{2 +} and Cd^{2 +} immobilization and the increase of available phosphate and organic matter. <i>ZitB</i>, <i>czcD</i>, <i>zntA</i>, and <i>cmtR</i> are the major heavy metal resistance genes and regulate metabolic pathways to make microbial community function more stable after soil remediation in phosphate mining wasteland.