Abstract Carbonate mineralization based on urea hydrolysis by bacteria has a significant implication in the remediation of heavy metals polluted environment, but a huge quantity of ammonium released due to the addition of urea may lead to non-point source pollution. In this study, a lead-resistant strain ZN5, identified as Brevibacillus laterosporus, which could induce different carbonate precipitations of Pb (II) through ammonification and nitrate assimilation processes without the addition of urea, was isolated. The maximum of pH values of bacterial fermentation suspensions were 9.07 and 9.22 during ammonification and nitrate assimilation processes, respectively. The minimum inhibitory concentrations of Pb (II) to strain ZN5 in two processes were 150 and 100 mg/L, respectively. Strain ZN5 could rapidly remove 94% and 70% of Pb (II) at an initial concentration of 15 mM through two processes, respectively. Furthermore, the induced carbonate precipitates of Pb (II) in ammonification and nitrate assimilation processes were dense spherical crystal of Pb3(CO3)2(OH)2 and loose irregular crystal of PbCO3, respectively, based on XRD and SEM-EDS. Besides, these two biominerals were relatively stable in dilute acid solution, especially the biomineral formed during nitrate assimilation process. These results showed that strain ZN5 had promising application in remediation of Pb-contaminated environment.

中文翻译：

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侧孢短芽孢杆菌 ZN5 在氨化和硝酸盐同化过程中诱导铅的不同碳酸盐沉淀

摘要 基于细菌水解尿素的碳酸盐矿化对重金属污染环境的修复具有重要意义，但由于尿素的加入释放出大量的铵盐，可能导致面源污染。在这项研究中，分离出一种耐铅菌株 ZN5，被鉴定为侧孢短芽孢杆菌，它可以在不添加尿素的情况下通过氨化和硝酸盐同化过程诱导不同的 Pb (II) 碳酸盐沉淀。在氨化和硝酸盐同化过程中，细菌发酵悬浮液的最大pH值分别为9.07和9.22。两种工艺中Pb(II)对菌株ZN5的最低抑菌浓度分别为150和100mg/L。菌株 ZN5 可以通过两个过程分别在 15 mM 的初始浓度下快速去除 94% 和 70% 的 Pb (II)。此外，基于 XRD 和 SEM-EDS，在氨化和硝酸盐同化过程中诱导的 Pb (II) 碳酸盐沉淀分别为致密的 Pb3(CO3)2(OH)2 球形晶体和松散的 PbCO3 不规则晶体。此外，这两种生物矿物在稀酸溶液中相对稳定，尤其是硝酸盐同化过程中形成的生物矿物。这些结果表明菌株ZN5在铅污染环境的修复中具有广阔的应用前景。基于XRD和SEM-EDS，在氨化和硝酸盐同化过程中诱导的Pb(II)碳酸盐沉淀分别为致密的Pb3(CO3)2(OH)2球形晶体和松散的PbCO3不规则晶体。此外，这两种生物矿物在稀酸溶液中相对稳定，尤其是硝酸盐同化过程中形成的生物矿物。这些结果表明菌株ZN5在铅污染环境的修复中具有广阔的应用前景。基于XRD和SEM-EDS，在氨化和硝酸盐同化过程中诱导的Pb(II)碳酸盐沉淀分别为致密的Pb3(CO3)2(OH)2球形晶体和松散的PbCO3不规则晶体。此外，这两种生物矿物在稀酸溶液中相对稳定，尤其是硝酸盐同化过程中形成的生物矿物。这些结果表明菌株ZN5在铅污染环境的修复中具有广阔的应用前景。