湿法冶金

生物冶金作为未来实现星际基地原位资源利用(ISRU)的一种有效手段，近年来引起了学界的关注。但在微重力效应下，链霉菌与矿物之间的相互作用机制尚不明晰。为探究这一问题，本研究利用回转器模拟了微重力效应下链霉菌Streptomyces sp.R76浸出矿物中的元素。结果表明：模拟微重力环境明显加速了Streptomyces sp.R76发育分化及代谢能力，主要表现在气生菌丝和孢子发育分化提前发生，同时有机酸产量有所提高；在模拟微重力效应下，Streptomyces sp.R76产生的乳酸和枸橼酸浓度分别为8.6、0.17 mmol/L,而在重力条件下，分别为5.8、0.04 mmol/L;当Streptomyces sp.R76与矿物共培养时，模拟微重力效应下的稀土元素浸出率为3‰,钙浸出率为0.11‰,而重力条件下的稀土元素浸出率仅为0.33‰,钙浸出率为0.08‰;Streptomyces sp.R76在微重力条件下产生的乳酸和枸橼酸是促进稀土、硅和钙元素从矿物中浸出的关键。

Biometallurgy has drawn the attention of the academic community in recent years as an effective way to achieve in-situ resource utilization(ISRU) in future interstellar bases.However, the mechanism of interaction between Streptomyces and minerals is still unclear under the effect of microgravity.To investigate this issue, simulating the leaching of elements from minerals by Streptomyces sp.R76 under microgravity using clinostats was studied.The results show that the simulated microgravity environment significantly accelerated Streptomyces sp.R76's development, differentiation, and metabolic capacity, which is primarily manifested in the early development and differentiation of aerial hyphae and spores, as well as the increase in organic acid. Streptomyces sp.R76 can produce lactic acid and citric acid at concentrations of 8.6 and 0.17 mmol/L under simulated microgravity and 5.8 and 0.04 mmol/L under gravity, respectively.When Streptomyces sp.R76 is co-cultured with minerals, the leaching rate of rare earth elements under simulated microgravity is 3‰,the leaching rate of calcium is 0.11‰.The leaching rate of rare earth elements under gravity is only 0.33‰ and the leaching rate of calcium is 0.08‰.The lactic acid and citric acid produced by Streptomyces sp.R76 under microgravity conditions are important factors in promoting the leaching of calcium, silicon, and rare earth elements from minerals.