The presence of cadmium (Cd) and chromium (Cr) contamination in soil poses an environmental risk to food safety. Microorganisms are crucial for biotransforming heavy metals, but their limited survival in contaminated soils hinders their application in bioremediation. Here, we isolated Lysinibacillus sp. OR-15, which effectively removed Cd(II) and reduced Cr(VI) from the culture. Proteomic analyses and heterologous expression assays showed that QueF, an NADPH-dependent reductase, enhanced bacterial resistance to Cd(II) and Cr(VI), enhancing metal removal capacity. The dry bacterial powder, produced through deep liquid fermentation and spray drying, contained 2.3 ×10¹⁰ viable cells per gram. It effectively reduced Cd and Cr levels in rice grains and maintained a concentration of 10⁵ per gram in soils even after 60 days of cultivation following one application. Scanning and microscopy analysis revealed that Lysinibacillus sp. OR-15 facilitated the formation of iron plaque on rice roots. The formation of iron plaque on the root surface serves as a protective barrier against the upward translocation of heavy metals. Our findings suggest that Lysinibacillus sp. OR-15 exhibits stable and effective properties as a factor for Cd and Cr adsorb on rice iron plaque, thus mitigating the levels of Cd and Cr in rice grains.

土壤中存在的镉 （Cd） 和铬 （Cr） 污染会对食品安全构成环境风险。微生物对于重金属的生物转化至关重要，但它们在受污染土壤中的生存有限，阻碍了它们在生物修复中的应用。在这里，我们分离了赖氨酸芽孢杆菌 OR-15，它有效地从培养物中去除了 Cd（II） 并减少了 Cr（VI）。蛋白质组学分析和异源表达测定表明，NADPH 依赖性还原酶 QueF 增强了细菌对 Cd（II） 和 Cr（VI） 的耐药性，增强了金属去除能力。通过深度液体发酵和喷雾干燥生产的干燥细菌粉末每克含有 2.3 ×10¹⁰ 个活细胞。它有效地降低了米粒中的 Cd 和 Cr 水平，即使在一次施用后耕作 60 天后，土壤中的浓度仍保持在每克 10⁵。扫描和显微镜分析显示，赖氨酸芽孢杆菌 （Lysinibacillus sp. OR-15） 促进了水稻根系铁斑块的形成。铁斑块在根表面形成，是防止重金属向上转移的保护屏障。我们的研究结果表明，赖氨酸芽孢杆菌 OR-15 作为 Cd 和 Cr 吸附在稻铁斑块上的因子表现出稳定有效的特性，从而降低了稻粒中 Cd 和 Cr 的水平。