Departamento de Ciencias del Agua y Medio Ambiente, Instituto Tecnológico de Sonora, 5 de Febrero 818 Sur, 85000, Ciudad Obregón, Sonora, México.
Environ Sci Pollut Res Int. 2019 Mar;26(7):6311-6318. doi: 10.1007/s11356-018-3963-1. Epub 2019 Jan 7.
The removal of heavy metals from acid mine drainage is a key factor for avoiding damage to the environment. The microalga Nannochloropsis oculata was cultured in an algal medium with 0.05, 0.1, 0.15, 0.2, and 0.25 mM copper under completely defined conditions to assess its removal capacity; the effects of copper on the cell density and lipid productivity of N. oculata were also evaluated. The results showed that N. oculata was able to remove up to 99.92 ± 0.04% of the copper content in the culture medium. A total of 89.29 ± 1.92% was eliminated through metabolism, and 10.70 ± 1.92% was removed by adsorption. These findings are favorable because they indicate that a large amount of copper was extracted due to the ability of the microalga to metabolize copper ions. The cell density, growth rate, and lipid content decreased with increased concentrations of copper in the culture medium. A positive effect on the fatty acid profile was found, as the saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) content improved when the copper concentration was higher than 0.1 mmol L, which can potentiate the production of high-quality biodiesel. N. oculata is a good option for the treatment of acid mine drainage due to its ability to eliminate a substantial percentage of the copper present. Moreover, combining different culture systems such that heavy metals are removed to non-toxic levels in the first stage and high cell densities, which promote lipid production, is obtained in the second stage would be an advantageous strategy.
从酸性矿山排水中去除重金属是避免环境破坏的关键因素。在完全定义的条件下，将微藻眼点拟微绿球藻培养在含有 0.05、0.1、0.15、0.2 和 0.25mM 铜的藻类培养基中，以评估其去除能力；还评估了铜对 N. oculata 细胞密度和产脂能力的影响。结果表明，N. oculata 能够去除培养基中高达 99.92±0.04%的铜含量。通过代谢总共去除了 89.29±1.92%，通过吸附去除了 10.70±1.92%。这些发现是有利的，因为它们表明由于微藻代谢铜离子的能力，大量的铜被提取出来。细胞密度、增长率和脂质含量随着培养基中铜浓度的增加而降低。发现对脂肪酸谱有积极影响，因为当铜浓度高于 0.1mmol L 时，饱和脂肪酸（SFA）和单不饱和脂肪酸（MUFA）的含量提高，这可以增强高质量生物柴油的生产。由于 N. oculata 能够去除大量存在的铜，因此它是处理酸性矿山排水的一种很好的选择。此外，将不同的培养系统结合起来，在第一阶段将重金属去除到无毒水平，并在第二阶段获得促进脂质生产的高细胞密度，将是一种有利的策略。
