草酸青霉对含钾矿物风化及钾溶出的影响

Bioweathering and K release of K-bearing minerals by Penicillium oxalicum

【目的】探讨含钾硅酸盐矿物在草酸青霉(Penicillium oxalicum)作用下的风化及钾溶出情况。【方法】利用等离子体发射光谱、X-射线能谱、X-射线光电子能谱分析了3种常见含钾硅酸盐矿物(钾长石、白云母和黑云母)在草酸青霉作用后浸出液和矿物表面元素含量的变化;通过X-射线衍射分析矿物晶相结构的变化;采用共聚焦激光扫描显微镜表征了草酸青霉在矿物表面形成的生物膜;测量了培养液中不同碳源与氮源组分对草酸青霉解钾的影响。【结果】草酸青霉对结构稳定的钾长石和白云母风化速率较低,相比而言黑云母容易被风化并释放可溶性钾元素;草酸青霉在矿物表面形成了网状结构的生物膜,有利于微环境的生成及有机酸在其内的富集,促进微环境内钾的释放,强化微生物对矿物的风化作用;草酸青霉对多种碳源及氮源都表现出较好的适用性。【结论】草酸青霉是一种能够促进多种含钾矿物风化和钾溶出的真菌,在堆肥和生物肥料领域具有广泛的应用前景。

[Objective] To study the effect of K release and weathering of K-bearing minerals by Penicillium oxalicum. [Methods] The element compositions in the liquid phase and on the mineral surface were determined by Inductively Coupled Plasma, X-ray Energy Dispersive Spectrometer and X-ray Photoelectron Spectroscopy. The crystal structure was analyzed by X-ray diffraction after the mineral was incubated with P. oxalicum. The biofilm formed onto K-bearing minerals was determined by Confocal Laser Scanning Microscope. The effect of carbon source and nitrogen source on K mobilization by P. oxalicum was also studied. [Results] Biotite showed less resistance to fungal bioweathering, compared with K-feldspar and muscovite, and P. oxalicum formed network structure biofilm where probably the organic acid was concentrated. Different carbon and nitrogen source could be used by P. oxalicum. [Conclusion] P. oxalicum can accelerate the bioweathering and K release of different K-bearing minerals and has application potential in compost and biofertilizer.