Heavy metal pollution of soil, particularly by mercury (Hg), is a problem that can seriously affect the environment and human health. For this reason, it is necessary to take steps to remediate these environments, prevent potential adverse effects, and restore these areas for subsequent use in agriculture, industry, ranching, and forestry. The present study has selected 40 bacterial strains from rhizosphere and bulk soil that grow naturally in high Hg-contaminated soils from the Almadén mining district in Ciudad Real, Spain. With the objective of evaluating the potential use of these strains in phyto-rhizoremediation, an evaluation and statistical analysis of their PGPR (Plant-Growth-Promoting Rhizobacteria) activity at different levels of Hg was carried out as the first condition of selection for their potential use in bioremediation. In addition, a Hg MBC (Maximum Bactericidal Concentration) was performed with the aim of selecting the strains with high Hg tolerance. Finally, strains with potential biotechnological use have been proposed according to the Bio-Mercury Remediation Suitability Index (BMRSI) criteria, which consider indole-3-acetic acid (IAA) production, acid 1- aminocyclopropane-1-carboxylic deaminase (ACCd) activity, phosphates solubilization, and siderophore production measured in the presence of Hg, as well as its MBC to Hg. The strains selected for further in vivo and in situ processes must reach at least an MBC (Hg) > 100 μg/mL and BMRSI ≥ 6.5.

中文翻译：

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使用 BMRSI 选择抗汞 PGPR 菌株用于生物修复目的

土壤重金属污染，尤其是汞（Hg）污染，是一个严重影响环境和人类健康的问题。出于这个原因，有必要采取措施修复这些环境，防止潜在的不利影响，并恢复这些区域以供随后的农业、工业、牧场和林业使用。本研究从西班牙雷亚尔城阿尔马登矿区的高汞污染土壤中自然生长的根际和大块土壤中选择了 40 种细菌菌株。为了评估这些菌株在植物根际修复中的潜在用途，对其在不同汞水平下的 PGPR（促进植物生长的根际细菌）活性进行了评估和统计分析，作为选择其潜力的首要条件用于生物修复。此外，进行汞 MBC（最大杀菌浓度）的目的是选择具有高汞耐受性的菌株。最后，根据生物汞修复适宜性指数 (BMRSI) 标准提出了具有潜在生物技术用途的菌株，该标准考虑了吲哚-3-乙酸 (IAA) 的产生、酸 1-氨基环丙烷-1-羧基脱氨酶 (ACCd) 的活性、磷酸盐溶解和铁载体产生在 Hg 存在下测量，以及它的 MBC 与 Hg。选择用于进一步体内和原位过程的菌株必须至少达到 MBC (Hg) > 100 μg/mL 和 BMRSI ≥ 6.5。根据生物汞修复适宜性指数 (BMRSI) 标准提出了具有潜在生物技术用途的菌株，该标准考虑了吲哚-3-乙酸 (IAA) 生产、酸 1-氨基环丙烷-1-羧基脱氨酶 (ACCd) 活性、磷酸盐在 Hg 存在下测量的增溶和铁载体产生，以及其 MBC 与 Hg。选择用于进一步体内和原位过程的菌株必须至少达到 MBC (Hg) > 100 μg/mL 和 BMRSI ≥ 6.5。根据生物汞修复适宜性指数 (BMRSI) 标准提出了具有潜在生物技术用途的菌株，该标准考虑了吲哚-3-乙酸 (IAA) 生产、酸 1-氨基环丙烷-1-羧基脱氨酶 (ACCd) 活性、磷酸盐在 Hg 存在下测量的增溶和铁载体产生，以及其 MBC 与 Hg。选择用于进一步体内和原位过程的菌株必须至少达到 MBC (Hg) > 100 μg/mL 和 BMRSI ≥ 6.5。