Abstract:
Indigenous microbial consortia are closely associated with soil inherent components including nutrients and minerals. Although indigenous microbial consortia present great prospects for bioremediation of vanadate [V(V)] contaminated soil, influences of some key components, such as available phosphorus (AP), on V(V) biodetoxification are poorly understood. In this study, surface soils sampled from five representative vanadium smelter sites were employed as inocula without pretreatment. V(V) removal efficiency ranged from 81.7 ± 1.4% to 99.5 ± 0.2% in batch experiment, and the maximum V(V) removal rates were positively correlated with AP contents. Long-term V(V) removal was achieved under fluctuant hydrodynamic and hydrochemical conditions in column experiment. Geobacter and Bacillus, which were found in both original soils and bioreactors, catalytically reduced V(V) to insoluble tetravalent vanadium. Phosphate-solubilizing bacterium affiliated to Gemmatimonadaceae were also identified abundantly. Microbial functional characterization indicated the enrichment of phosphate ABC transporter, which could accelerate V(V) transfer into intercellular space for efficient reduction due to the structural similarity of V(V) and phosphate. This study reveals the critical role of AP in microbial V(V) decontamination and provides promising strategy for in situ bioremediation of V(V) polluted soil.
摘要:
土著微生物聚生体与土壤固有成分(包括养分和矿物质)密切相关。尽管土著微生物联盟在钒酸盐[V(V)]污染土壤的生物修复方面具有广阔的前景,一些关键部件的影响,如有效磷(AP),对V(V)的生物脱毒了解甚少。在这项研究中,从五个具有代表性的钒冶炼厂现场取样的表层土壤被用作接种物,无需预处理。批量实验中V(V)去除效率为81.7±1.4%~99.5±0.2%,最大V(V)去除率与AP含量呈正相关。在色谱柱实验中,在波动的流体力学和水化学条件下实现了长期V(V)去除。Geobacter和Bacillus,在原始土壤和生物反应器中都有发现,将V(V)催化还原为不溶性四价钒。还大量鉴定了隶属于Gemmatimonadaceae的溶解磷酸盐的细菌。微生物功能表征表明磷酸盐ABC转运蛋白的富集,由于V(V)和磷酸盐的结构相似性,可以加速V(V)转移到细胞间隙以有效还原。这项研究揭示了AP在微生物V(V)净化中的关键作用,并为V(V)污染土壤的原位生物修复提供了有希望的策略。