【作者】 闫超；

【导师】 连宾；

【作者基本信息】 贵州大学 ， 微生物学， 2008， 硕士

【摘要】 我国可溶性钾矿资源极其缺乏,严重制约了钾肥生产和应用,国际钾肥市场被几个主要发达国家所垄断,钾肥价格连年上涨,这些因素使得我国农业生产中钾肥施用量严重不足,土壤缺钾情况日趋严重,影响了农业生产的快速发展。相反,我国低品位含钾矿物资源储量巨大,如果能够采用一定的方法有效地利用低品位含钾矿物,促使其释放活性钾素,那么对于缓解我国土壤缺钾问题会有所帮助。本文初步研究了一株兼性嗜热真菌烟曲霉(Aspergillus fumigatus)TH003菌株以及一株胶质芽胞杆菌(Bacillus mucilaginosus)BM03菌株对低品位含钾矿物的生物转化作用。采用固体培养方法研究了烟曲霉TH003菌株对低品位含钾矿物的生物转化作用,多种配方对比实验结果证明,以平菇栽培废料为主要基质并添加一定量其他有机质的培养基配方,微生物对含钾矿物的转化作用效果较好;通过单因子实验和正交实验优化,矿粉添加量60%、培养时间20d、培养温度40℃的实验条件组合,微生物作用含钾矿粉的释钾量较高,可达1965.079μg/g。利用硅酸盐细菌BM03菌株对含钾矿物进行生物浸出,钾释出量达到616.227μg/g。将两种作用方法组合起来开展对含钾矿物生物转化的研究,结果表明,矿粉钾的释出量最终能够达到2354.980μg/g。复合工艺对低品位含钾矿物的作用分为烟曲霉TH003菌株的微生物转化作用和硅酸盐细菌BM03菌株的生物浸出作用,因此,复合工艺的作用机理也包括这两个部分。烟曲霉TH003菌株的微生物转化作用机理,通过实验对比能够发现烟曲霉TH003菌株对低品位含钾岩石有解钾作用,这种作用的机理解释可以分为酸解作用、络解作用、离子交换吸附和微生物物理破坏作用等。硅酸盐细菌BM03菌株对含钾矿物的解钾作用机理分为直接作用、间接作用和协同作用三种,直接作用是指硅酸盐细菌对含钾矿物的直接磨蚀或溶蚀作用,间接作用是指硅酸盐细菌代谢产物对含钾矿物的化学降解作用,协同作用是指直接作用和间接作用中的多种作用形式同时存在;硅酸盐细菌能够与含钾矿物形成细菌-矿物复合体,这为细菌与矿物之间的相互作用提供了有利条件,在复合体这个微环境中细菌对含钾矿物的作用更为充分。与传统的含钾矿石加工工艺相比,生物转化方法对环境友好,无污染,且产物中富含多种可被植物吸收利用的营养成分,可用作进一步研制多功能有机肥料的基质。本文为研发新型低品位含钾矿物的生物加工技术提供了参考资料。更多还原

【Abstract】 In our country, the scarcity of soluble potassium mineral seriously affects the production and application of potassium fertilizer. What’s more, the international potassium market is monopolized by some developed countries, which results in the continuously rise of potassium’s price. All the above reasons result in seriously lack of use of potassium in the agricultural production. With the bad situation deteriorate day by day; the development of agriculture industry is restricted. Reversely, our country is full of low-grade potassium-bearing minerals. If some special methods on the low-grade potassium-bearing minerals could be used to get the released active potassium element, the potassium-shortage situation will somewhat be relieved. So, a preliminary research on the bioconversion effect of Aspergillus fumigatus TH003 and Bacillus mucilaginosus BM03 on low-grade potassium-bearing minerals were made in this article.Through the researchs on the bioconversion effect of A. fumigatus TH003 on low-grade potassium-bearing minerals by using solid cultivate method with using some different cultivate mediums. People obtained better effects if oyster mushroom’s cultivate waste material were added with some other organic elements as the cultivate medium. Under the conditions of mineral powder account for 60%, cultivate time 20d, cultivate temperature 40℃, the result of 1965.079μg/g potassium was received with single factor experiment and orthogonal experiment. And the potassium of 616.227μg/g was obtained when use B. mucilaginosus BM03 to bioleaching the potassium-bearing minerals. With the combination use of the two methods maintained above, the potassium released from the mineral powder reached 2354.980μg/g.The composite technology of potassium-bearing minerals divides into two steps. The first step was biotransformation by A. fumigatus TH003, and bioleaching of B. mucilaginosus BM03 in the second step. Therefore, the mechanism of composite technology includes two parts. The compared experiment showed that A. fumigatus TH003 can dissolution potassium mineral from low-grade potassium-bearing minerals. This mechanism could be realized as the combined effect of the hydrolyzation acid, complex hydrolyzation, iron exchange adsorption effect, microorganism physics destructive effect and the like. The mechanism of bacteria on release potassium from potassium-bearing minerals includes direct mechanism, indirect mechanism and combined mechanism. Direct mechanism means the dissolution or corrosion effect of silicate bacteria on minerals. Indirect mechanism means the chemical degradation effect of the metabolites of silicate bacteria on minerals. The effect of bacteria on potassium-bearing minerals will be more obvious under the bacteria-mineral complex condition.Compare with the traditional process of potassium-bearing minerals, the bioconversion method is environment friendly and pollution free. The offspring of the process contain lots of nutrient elements that could be absorbed by plants. The elements could also be processed to multifunction organic fertilizers. The article could be used as important reference on developing new process on low-grade potassium-bearing minerals.更多还原