【作者】 袁向利；

【导师】 吕早生；

【作者基本信息】 武汉科技大学 ， 生物化工， 2010， 硕士

【摘要】 本研究以湖北省铜禄山铜山口矿区的酸性矿坑水为材料,进行At.f菌的分离纯化,并对其生长特性、浸矿效果、浸出机理进行了初步研究。用9K液体培养基对采集的水样进行富集培养和分离纯化,纯化后的菌株经16S rDNA鉴定后为嗜酸氧化亚铁硫杆菌,命名为C1。C1菌的最适生长pH为2.0、生长温度为30℃、接种量为10%和摇床转速为150 r/min。在温度为30℃、初始pH为1.5、摇床转速为135 r/min、接种量为2%、矿石粒度为74-97μm、加入的FeSO4·7H2O为44.7 g/L、黄铁矿为15 g/L和磷矿为10 g/L的条件下,经过28 d的浸出,浸磷率达77.19%。选取初始pH,接种量,转速,矿石粒度4个因素进行正交实验,各因素对实验结果影响的显著性顺序为pH>接种量>转速>矿石粒度。在浸矿培养基中加入吐温类表面活性剂后,可有效地提高浸磷率,当吐温20,40,60,80用量分别为10 g/m3、10 g/m3、10 g/m3和50 g/m3时效果最佳,此时浸磷率分别提高了31.00%,36.48%,45.19%和41.91%。采用普通浸矿法时,经过4 d的浸出,9K,9K+S及Waksman培养基中,浸磷率分别为57.07%,76.75%,58.13%,而在这三种培养基中采用批浸矿法经过22 d的浸出,浸磷率分别为48.41%,58.89%,25.16%。在以黄铁矿为能源的培养基中,紫外线照射诱变C1菌3 min,当用此诱变菌株对磷矿粉经过14 d的浸出,浸磷率达20.07%,比未处理的原始菌株提高了31.69%;微波辐射诱变C1菌10 s,用此诱变菌株对磷矿粉经过14 d的浸出,浸磷率达21.96%,比原始菌株的浸出率提高了51.87%;用浓度为0.02 mol/L亚硝酸诱变C1菌,诱变菌的浸磷率比初始菌提高了35.01%;用0.6%硫酸二乙酯诱变C1菌15 min,诱变菌的浸磷率比原始菌株提高了31.03%;用1.0%盐酸羟胺诱变C1菌,诱变菌的浸磷率比原始菌株提高了33.31%;经过微波和浓度为0.02 mol/L亚硝酸复合诱变C1菌,此诱变菌的浸磷率达24.86%,比出发菌株提高了28.14%;C1菌经硫酸二乙酯和盐酸羟胺复合诱变后,对磷矿的浸出率比空白有所降低。C1菌在矿物表面经过40 min后达到吸附平衡,此时最大吸附量为41.48%。C1菌对磷矿石经过21 d的浸出,浸磷率达25.71%,比化学浸出法的9.89%提高1.59倍。培养基中加入一定量的甘氨酸、赖氨酸和谷氨酸能够提高浸磷率,而加入一定量的亮氨酸后,浸磷率反而下降。甘氨酸、赖氨酸和谷氨酸的最佳用量分别为0.5 g/L、0.5 g/L、1 g/L,此时浸磷率提高了24.07%、12.03%、7.6%,其中赖氨酸和谷氨酸的作用没有甘氨酸明显。培养基中加入一定量的果糖能够提高浸磷率,而加入一定量的阿拉伯糖后,浸磷率反而下降。果糖的最佳用量为0.5 g/L,此时浸磷率提高了15.54%。更多还原

【Abstract】 A strain C1 was isolated and purified from acid mine drainage of Tong Shan Kou mine at Tong Lu Shan in Hubei province and its growth characteristics, phosphate ore leached conditions and leaching mechanism was studied. The strain C1 was isolated from 9K medium and identified as Acidithiobacillus ferrooxidans by 16S rDNA analysis and it was named after C1. C1’s optimum growth conditions were temperature 30℃, initial pH 2.0, inoculation amount 10% and rotation speed 150 r/min. The phosphate ore leached rate was 77.19% after 28 d when the temperature 30℃, initial pH 1.5, rotation speed 135 r/min, inoculation amount 2%, particle size of phosphate ore 74-97μm, FeSO4·7H2O 44.7 g/L, pyrite 15 g/L and phosphorous ore 10 g/L. Initial pH, inoculation amount, rotation speed and particle size of phosphate ore were selected for orthogonal experiment and the significant order of influence factors was pH>inoculation amount>rotate speed>paticale size of phosphate ore. Tween 20, 40, 60, 80 could improve the leached rate of the ore and the optimal dosage was 10 g/m3, 10 g/m3, 10 g/m3, 50 g/m3 respectively and the phosphate ore leached rate increase about 31.00%, 36.48%, 45.19% and 41.91% under these conditions. The phosphorus ore leached rate could reach 57.07%, 58.13%, 76.75% respectively after 4 d by ordinary leaching method among 9K, Waksman and 9K+S medium. However the phosphorus ore leached rate only reach 48.41% 25.16%, 58.89% after 22 d by batch leaching method in these three kinds of medium. When using pyrite as an energy source the phosphorus ore leached rate was 20.07% after 14 d by the bacteria which was mutated by UV for 3 min and was 31.69% higher than that of the control, the phosphorus ore leached rate was 21.96% after 14 d by the bacteria which was mutated by microwave for 10 s and was 51.87% higher than that of the control, the phosphorus ore leached rate was 20.98% after 14 d by the bacteria which was mutated by 0.02 mol/L nitrous acid and was 35.01% higher than that of the control, the phosphorus ore leached rate was 20.65% after 14 d by the bacteria which was mutated by 0.6% diethyl sulfate (DES) for 15 min and was 31.03% higher than that of the control, the phosphorus ore leached rate was 21.45% after 14 d by the bacteria which was mutated by 1.0% hydroxylamine and was 33.31% higher than that of the control, the rate of phosphorus ore leached was 24.86% after 14 d by the bacteria which was multiple mutated by microwave and different concentrations of nitrous acid and was 28.14% higher than that of the control, DES-mutated bacteria were then muti-mutated with different concentrations of hydroxylamine, but the phosphorus ore leached rate of multiple mutated C1 was lower than the control.Strain C1 reached adsorption equilibrium on the mineral surface after 40 min and the maximum adsorbing capacity was 41.48%. The phosphorus ore leached rate by strain C1 is 25.71% which was higher than 9.89% by chemical leaching method after 21 d. A certain amount of glycin, lysine and glutamic acid rather than leucine in the medium could improve phosphorus ore leached rate. The optimal dosage of glycin, lysine and glutamic acid was 0.5 g/L, 0.5 g/L and 1 g/L respectively and the phosphorus ore leached rate was about 24.07%、12.03%、7.6% higher than the control, but the effect of lysine and glutamic acid were not obvious.A certain amount of glucose rather than arabinose in the medium could improve phosphorus ore leached rate. The optimal dosage of glucose was 0.5 g/L and the phosphorus ore leached rate was about 15.54% higher than the control.更多还原