微生物分解钾长石的机理研究

Extracting potassium from potassium feldspar to produce potassium fertilizer is an effective approach for making up for the deficiency of potassium of potassium fertilizer production industry. Microorganism-based potassium extraction is a promising method for potassium production from potassium feldspar. The comprehension to molecular mechanism of decomposing potassium mineral by potassium-solubilized bacterium is pivotal to high-effectively extract potassium from potassium feldspar. The dissolution kinetics of silicon, aluminum and potassium from potassium feldspar, and the changes of surface structure and chemical composition of potassium feldspar in the process of potassium solution by potassium-solubilized bacteria will be investigated to find out the priority elements interacted with the active substances decomposing the potassium feldspar. At the same time, total DNA from potassium-solubized bacterium will be isolated, and then a DNA library will be constructed to screen the potassium-solubized related genes. Subsequently, the obtained potassium-solubized related genes will be expressed in E. coli. Finally, the active substances decomposing the potassium feldspar will isolated and identified from recombinant strain or bacterial culture. The characteristics of structure change of potassium feldspar plus the kowledge of the gene related to biosynthesis of the active substances decomposing the potassium feldspar will clarify molecular mechanism of decomposing potassium mineral by potassium-solubilized bacterium. This work will first uncover chemical nature of the active substances decomposing the potassium feldspar of microoganism. The construction of genetic engineering bacteria decomposing the potassium feldspar will provide technological support for potassium production using microbial fermentation method and also offer a theoretical basis for bionically decomposing potassium feldspar using isolated or synthesized activity substances.

从钾长石中提取钾来制造钾肥将是解决我国钾肥制造企业缺钾现状的有效途径。利用微生物法从钾长石中提取钾是最具前途的提钾方法。弄清解钾菌的解钾机理是从钾长石中高效提取钾的关键。通过对解钾菌解钾过程中钾、硅和铝的溶出动力学和钾长石表面结构变化、化学组成变化的研究，找出解钾活性物质与钾长石相互作用的优先元素。同时构建解钾菌DNA文库，筛选解钾活性物质相关基因，并在大肠杆菌中对活性物质合成相关基因进行表达，从重组菌株或其培养液中分离、鉴定解钾活性物质。结合钾长石被解钾菌分解过程中结构变化规律，阐明解钾菌解钾的分子机理。这项工作将首次揭示微生物解钾活性物质的化学本质，通过构建高效分解钾长石的工程菌为利用微生物发酵法从钾长石提取钾的工业生产提供技术支持，以及为用分离或合成的活性物质进行仿生分解钾长石提供理论依据。

从钾长石中提取钾来制造钾肥将是解决我国钾肥不足的有效途径，利用微生物法从钾长石提钾是最具有前途的方法。为此，本项目通过从钾长石矿区土壤中筛选得到一系列具有解钾功能的菌株，通过诱变，基因组改组等方法选育出高效解钾菌株。.通过对解钾菌解钾过程中钾、铝和硅的溶出动力学，钾长石表面化学组成变化的研究，发现优先溶出元素为铝。通过对解钾菌全DNA测序，DNA文库构建与筛选，已得到含解钾基因的大片段，并在大肠杆菌中进行表达，从培养液中分离得到解钾物质为羟基酸和聚羟基酸，从而提出解钾机理为有机酸对钾长石中铝进行配位溶出，使钾长石分解，使得钾溶出。