K-Extraction from Muscovite by the Isolated Fungi

Abstract

The aim of this work was to isolate and identify the muscovite-solubilizing microorganisms, and then to exploit the mechanism of K-extraction by the isolated microorganisms. Ten strains of microorganisms were isolated from soil sample in K-bearing mineral area (Anhui province, China) using Aleksandov agar medium, which had different degrees of muscovite-solubilizing in the K-extraction experiments. After 15-day incubation, the K-extraction ability was evaluated through dissolved structural element of muscovite in aqueous medium (K, Al, Si) by Inductively Coupled Plasma. Four best muscovite-solubilizing microorganisms were identified by 18S rDNA analysis as Penicillium purpurogenum, Talaromyces radicus, Aspergillus fumigatus and Aureobasidium pullulans, respectively. Furthermore, organic acids in the medium were determined by high performance liquid chromatography, and the surface morphology and composition of original and leached muscovite were evaluated using scanning electron microscopy and energy dispersive spectroscopy. According to these analytical results, it was deducted that the interactions between fungi and muscovite, along with excreted organic acids and K-adsorption by the fungal hyphae contribute to muscovite weathering and K-release.

Keywords:

• fungi
• K-extraction
• mineral weathering and dissolution
• muscovite
• Penicillium purpurogenum

Acknowledgments

We thank Chairman Li of the Anhui Huayue Mineral Materials Company, Limited for permission and help to obtain the soil samples.

Funding

The authors wish to acknowledge National Natural Science Foundation of China (No. 21376085) and China Postdoctoral Science Foundation (No. 2012M510809) for their financial support.