Departamento de Investigación y Posgrado en Alimentos, Microbiology and Micotoxins Laboratory, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Sonora, C.P., 83000, Hermosillo, Mexico.
Bioremediation Laboratory, Departamento de Ingeniería Química y Metalurgia, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Sonora, C.P., 83000, Hermosillo, Mexico.
Environ Sci Pollut Res Int. 2020 Aug;27(23):28545-28560. doi: 10.1007/s11356-020-07747-y. Epub 2020 Feb 13.
Heavy metals are toxic especially when they are introduced into the environment due to anthropogenic activities such as metallurgy, mining, and tanning. Removing these pollutants has become a worldwide concern since they cannot be degraded into nontoxic forms causing extended effects in the ecosystems. The use of an Aspergillus australensis was evaluated in order to remove Cu from simulated wastewater. The fungus was isolated from river sludges contaminated with heavy metals and was first evaluated for the determination of Cu tolerance levels. Microscopic fluorescence analysis was carried out to determine the effect of Cu presence on the viability, cellular components, polyhydroxyalkanoates production, and oxidative stress of the fungus, as a response to the stress caused by exposure to metal. In order to achieve copper removal, the A. australensis biomass was produced using batch cultures, and the mycelium was immobilized on a textile media in order to compare the copper-removal efficiency of live or dead biomass. The optimal values of pH and temperature for biomass production were established by using a surface response analysis. Live immobilized biomass was capable of removing Cu from 1.54 ± 0.19 to 2.66 ± 0.26 mg of copper/ g of dry biomass, while values of 1.93 ± 0.03 to 2.36 ± 0.29 mg of copper/g of dry biomass were observed when dead biomass was used. As was expected, copper removal using biomass varied depending on the pH and temperature used.
重金属具有毒性，尤其是当它们由于人为活动（如冶金、采矿和制革）而进入环境时。由于这些污染物不能降解为无毒形式，从而对生态系统造成长期影响，因此去除这些污染物已成为全球关注的焦点。为了去除模拟废水中的铜，评估了一株澳大利亚青霉（Aspergillus australensis）的去除效果。该真菌是从受重金属污染的河底淤泥中分离出来的，首先对其铜耐受水平进行了测定。采用荧光显微镜分析方法，研究了铜的存在对真菌活力、细胞成分、多羟基烷酸酯（PHA）产量和氧化应激的影响，以响应暴露于金属所带来的胁迫。为了实现铜的去除，采用分批培养生产了 A. australensis 生物量，并将菌丝体固定在纺织介质上，以比较活或死生物量的铜去除效率。采用曲面响应分析确定了生物量生产的最佳 pH 值和温度。活固定化生物量能够从 1.54±0.19 到 2.66±0.26 mg 铜/g 干生物量中去除铜，而使用死生物量时，观察到的铜去除值为 1.93±0.03 到 2.36±0.29 mg 铜/g 干生物量。正如预期的那样，生物量的铜去除率取决于使用的 pH 值和温度。
