Department of Biotechnology and Biosciences, State University of Milano-Bicocca, Milano, Italy.
Institute of Geotechnics of the Slovak Academy of Sciences, Watsonova 45, Kosice, 040 01, Slovakia.
Arch Microbiol. 2024 May 22;206(6):275. doi: 10.1007/s00203-024-04005-4.
In many European regions, both local metallic and non-metallic raw materials are poorly exploited due to their low quality and the lack of technologies to increase their economic value. In this context, the development of low cost and eco-friendly approaches, such as bioleaching of metal impurities, is crucial. The acidophilic strain Acidiphilium sp. SJH reduces Fe(III) to Fe(II) by coupling the oxidation of an organic substrate to the reduction of Fe(III) and can therefore be applied in the bioleaching of iron impurities from non-metallic raw materials. In this work, the physiology of Acidiphilium sp. SJH and the reduction of iron impurities from quartz sand and its derivatives have been studied during growth on media supplemented with various carbon sources and under different oxygenation conditions, highlighting that cell physiology and iron reduction are tightly coupled. Although the organism is known to be aerobic, maximum bioleaching performance was obtained by cultures cultivated until the exponential phase of growth under oxygen limitation. Among carbon sources, glucose has been shown to support faster biomass growth, while galactose allowed highest bioleaching. Moreover, Acidiphilium sp. SJH cells can synthesise and accumulate Poly-β-hydroxybutyrate (PHB) during the process, a polymer with relevant application in biotechnology. In summary, this work gives an insight into the physiology of Acidiphilium sp. SJH, able to use different carbon sources and to synthesise a technologically relevant polymer (PHB), while removing metals from sand without the need to introduce modifications in the process set up.
在许多欧洲地区，由于本地金属和非金属原材料的质量较低，且缺乏提高其经济价值的技术，这些原材料的开发利用程度较低。在此背景下，开发低成本和环保的方法至关重要，例如金属杂质的生物浸出。嗜酸菌属 SJH 可通过将有机基质的氧化与 Fe(III)的还原偶联来将 Fe(III)还原为 Fe(II)，因此可用于从非金属原材料中生物浸出铁杂质。在这项工作中，研究了嗜酸菌属 SJH 的生理学特性以及在补充了各种碳源的培养基中和在不同供氧条件下从石英砂及其衍生物中还原铁杂质的情况，突出了细胞生理学和铁还原之间的紧密联系。尽管已知该生物体为需氧生物，但在氧气限制下培养至生长指数期时，可获得最大的生物浸出性能。在碳源中，葡萄糖已被证明可支持更快的生物量生长，而半乳糖则允许实现最高的生物浸出率。此外，嗜酸菌属 SJH 细胞可以在该过程中合成和积累聚-β-羟基丁酸（PHB），这是一种在生物技术中有相关应用的聚合物。总之，这项工作深入了解了嗜酸菌属 SJH 的生理学特性，该菌能够利用不同的碳源并合成具有技术相关性的聚合物（PHB），同时无需对工艺设置进行修改即可从砂中去除金属。
