The presence of manganese (Mn) in drinking water causes aesthetic, operational, and health problems. Removal of Mn(II) by the use of Mn oxidizing microorganisms in biofiltration processes has been studied leading to a more economical and environmentally friendly process than conventional treatments with chemical products. There are multiple reports in temperate regions, but little information under tropical conditions, concerning Mn(II) removal by microorganisms. In this study, 13 autochthonous culturable manganese oxidizing bacteria isolated from water of two wells with ∼0.6 mg L⁻¹ and ∼0.2 mg L⁻¹ Mn(II), respectively, were evaluated in vitro to determine their potential as inoculums for application in biofiltration processes. The oxidation capacity of Mn(II) was evaluated by a qualitative test with Leucoberbelin blue I and the Mn(II) removal was quantified by measurements of the residual Mn(II) in a culture broth with an initial concentration of 5.9 mg L⁻¹. The biofilm formation capacity of the strains was also determined by crystal violet staining and by quantification of polysaccharides of extracellular polymeric substances. Three strains showed the highest percentage of Mn(II) removal in the culture in broth, two belonging to the genus Aeromonas (HAC-12 and RUE-1), with removal values of 42.5% and 40.1%, respectively, and one belonging to the genus Stenotrophomonas (S-3), with 40.3% removal. Besides, HAC-3B and RUE-6A showed the highest production of exopolysaccharides. These results allowed the selection of an Aeromonas strain (HAC-12) and one Stenotrophomonas strain (S-3) as possible candidates to be used as inoculums in biofilters for the removal of Mn(II) from groundwater.

中文翻译：

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锰（II）氧化和去除中涉及的本地热带热带细菌

饮用水中的锰（Mn）会引起美学，操作和健康问题。已经研究了在生物过滤过程中使用Mn氧化微生物去除Mn（II）的方法，该方法比传统的化学产品处理方法更加经济和环境友好。在温带地区有许多报道，但是在热带条件下有关微生物去除Mn（II）的信息很少。在这项研究中，从两个井中分别分离出约0.6 mg L ^-1和〜0.2 mg L ^-1 Mn（II）的水中分离出的13种自生可培养锰氧化细菌进行了体外评估。确定它们作为生物过滤过程中接种物的潜力。锰（II）的氧化能力通过亮白铁蛋白蓝I的定性测试进行评估，并且锰（II）的去除通过测量初始浓度为5.9 mg L ^-1的培养液中残留的锰（II）来量化。菌株的生物膜形成能力还通过结晶紫染色和细胞外聚合物质的多糖定量来确定。在肉汤培养物中，三种菌株显示出最高的Mn（II）去除率，其中两种属于气单胞菌属（HAC-12和RUE-1）的去除率分别为42.5％和40.1％，其中一个属于甜食单胞菌属（S-3），去除率为40.3％。此外，HAC-3B和RUE-6A的胞外多糖产量最高。这些结果允许选择一种气单胞菌菌株（HAC-12）和一种嗜单胞菌菌株（S-3）作为可能的候选物，以用作生物过滤器中的接种物，以从地下水中去除Mn（II）。