Biological Absorpation And Degradation Of Potassium Bearing Minerals By Thermophilic Fungi

Microorganism was one of the life forms that has not only a large number of species but also the most widespread on the surface of the earth. It could transform our earth by diverse pathways. The interaction between microorganism and mineral occurs continually. One of the interactions is to accelerate the weathering mineral by the activities of microorganism. The research indicated that the mineral provides the energy sources, nutrient and electron acceptor to microorganism which is the indispensably survive condition. On the other hand, the metabolism of microorganism stimulates the dissolution and deposition of mineral.Potassium fertilizer is in short supply in China because of lack of soluble potash resources. However, there is a considerable resource of insoluble potassium in soil minerals or rocks. This type of potassium mainly exists in aluminum silicate minerals. This form of potassium can not be absorbed directly by plants. So it is very important in theory and practice to study how to release potassium from potassium-bearing soil minerals or rocks. Biological action is regarded as an effective method. Recently, a number of papers have been published about bacterial dissolution of potassium-bearing minerals but few have reported the effects of fungi on potassium release.In order to study degradation of potassic mineral by fungi, we isolated a thermophilic fungi strain TH003 from compost. The strain can use extract potassium from rocks as a nutrient. The strain was identified as Aspergillus fumigatus based on its morphological characteristics and molecular result. We studied mineral dissolution by this strain. The strain was able to dissolve mineral granules of potassium-bearing rocks in the growth medium apparently as a result of attachment of mycelium to mineral surfaces. Under scanning electron microscopy and atomic force microscopy, complex associations between mineral particles and mycelia and dissolutions were apparent. The layer silicate minerals were degraded easier than other silicates. Possible mechanisms of potassium release from soil mineral or rocks by fungi will be discussed.This paper focuses on mineral weathering by A. fumigatus. The results of this paper are shown below:In this research , two bacillus (TH001,TH002) and one fungi (TH003)was separated from compost. Through the experiment, it was found the fungi had great capacity of absorption and decomposition of mineral. It was identified as A. fumigatus. The strains are inoculation on the...