Barboza Natália Rocha, Amorim Soraya Sander, Santos Pricila Almeida, Reis Flávia Donária, Cordeiro Mônica Mendes, Guerra-Sá Renata, Leão Versiane Albis
Laboratório de Bioquímica e Biologia Molecular, Departamento de Ciências Biológicas (DECBI) and Instituto de Ciências Exatas e Biológica (ICEB), Universidade Federal de Ouro Preto, 35400-000 Ouro Preto, MG, Brazil.
Laboratório de Bio&Hidrometalurgia, Departamento de Engenharia Metalúrgica e de Materiais (DEMET), Escola de Minas, Universidade Federal de Ouro Preto, 35400-000 Ouro Preto, MG, Brazil.
Biomed Res Int. 2015;2015:925972. doi: 10.1155/2015/925972. Epub 2015 Dec 1.
Manganese is a contaminant in the wastewaters produced by Brazilian mining operations, and the removal of the metal is notoriously difficult because of the high stability of the Mn(II) ion in aqueous solutions. To explore a biological approach for removing excessive amounts of aqueous Mn(II), we investigated the potential of Mn(II) oxidation by both consortium and bacterial isolates from a Brazilian manganese mine. A bacterial consortium was able to remove 99.7% of the Mn(II). A phylogenetic analysis of isolates demonstrated that the predominant microorganisms were members of Stenotrophomonas, Bacillus, and Lysinibacillus genera. Mn(II) removal rates between 58.5% and 70.9% were observed for Bacillus sp. and Stenotrophomonas sp. while the Lysinibacillus isolate 13P removes 82.7%. The catalytic oxidation of Mn(II) mediated by multicopper oxidase was not properly detected; however, in all of the experiments, a significant increase in the pH of the culture medium was detected. No aggregates inside the cells grown for a week were found by electronic microscopy. Nevertheless, an energy-dispersive X-ray spectroscopy of the isolates revealed the presence of manganese in Stenotrophomonas sp. and Lysinibacillus sp. grown in K medium. These results suggest that members of Stenotrophomonas and Lysinibacillus genera were able to remove Mn(II) by a nonenzymatic pathway.
锰是巴西采矿作业产生的废水中的一种污染物，由于Mn(II)离子在水溶液中的高稳定性，去除这种金属非常困难。为了探索一种去除过量水溶液中Mn(II)的生物学方法，我们研究了来自巴西锰矿的菌群和细菌分离株氧化Mn(II)的潜力。一个细菌菌群能够去除99.7%的Mn(II)。对分离株的系统发育分析表明，主要微生物是嗜麦芽窄食单胞菌属、芽孢杆菌属和赖氨酸芽孢杆菌属的成员。芽孢杆菌属和嗜麦芽窄食单胞菌属的Mn(II)去除率在58.5%至70.9%之间，而赖氨酸芽孢杆菌分离株13P的去除率为82.7%。未检测到多铜氧化酶介导的Mn(II)催化氧化；然而，在所有实验中，均检测到培养基的pH值显著升高。通过电子显微镜未发现培养一周的细胞内有聚集体。尽管如此，对分离株的能量色散X射线光谱分析显示，在K培养基中生长的嗜麦芽窄食单胞菌属和赖氨酸芽孢杆菌属中存在锰。这些结果表明，嗜麦芽窄食单胞菌属和赖氨酸芽孢杆菌属的成员能够通过非酶途径去除Mn(II)。
