广西某低品位金矿的浸出试验研究

针对广西某微细粒浸染、品位低的风化型氧化金矿的特点,采用堆淋浸出方法,通过一系列正交条件试验研究,获得金浸出率为81.50%的较佳指标。

Optimization of Expression Conditions for Immunodominant Membrane Protein Gene of Phytoplasmas in E.coli

[Objective] This study aimed to increase the expression level of immun- odominant membrane protein gene （Imp） of phytoplasmas in E. coil BL21 （DE3）. [Method] On the basis of orthogonal experiment, effects of different culture conditions on recombinant bacteria E. coil BL21-pET-28a（＋）-Imp were investigated. Based on the obtained optimal culture condition, effects of different induction conditions on the ex- pression level of Imp protein were explored. The expression level of Imp fusion pro- tein was analyzed by using SDS-PAGE and Gene Tools software. [Result] The re- sults showed that the optimal conditions for culture were at 37℃, pH 7.0, with liq- uid volume of 20% and oscillation speed of 200 r/min, for induction were at 37℃ for 6 h, with initial OD600 of about 1.5 and IPTG final concentration of 0.1 mmol/L. [Conclusion] The expression level of Imp achieved 70.98 mg/L under the optimal conditions. Optimized conditions for expression of Imp fusion protein in E. coil were determined.

Optimum conditions to treat high-concentration microparticle slime water with bioflocculants

We studied how bioflocculants,produced by white-rot fungi,affect flocculation in slime water.Based on a test in an orthogonal design,flocculation conditions were optimized.The results show that flocculation activity is at its highest when the following conditions are met:slime water concentration 27.42 g/L;coagulant aid(CaCl_2) mass concentration 5.0 g/L;two-segment stirrings:the first at a stirring speed of 60 r/min for 180 s and the second 180 r/min for 60 s;a pH of 11 and a flocculant concentration of 15 mL/L.The flocculation activity can be up to 98.71%of bioflocculants at the time.Further experiments indicate that most of the flocculation active material is found outside the mycelium cells.This is the extracellular secretion produced by mycelium cells during the fermentation process.This flocculant has strong thermal stability.Many kinds of cations have a flocculation function to assist bioflocculants.This aid-flocculation effect of the divalent cation Ca^(2+) is obvious in the bioflocculant produced by the white-rot fungus.Therefore,this is of great value when applied to control engineering in the battle against water pollution.

Study on melting available silicone from coal gangue

Available silicone was melted from coal gangue samples from Hancheng dig- gings through calcination, digestion, and other means. The best calcination temperature was determined from a range of 550-1 150 ℃; and the best time, from a range of 0.5-5 h by colorimetry method. The proper ratio of coal gangue, limestone, sodium carbonate, and caustic soda was then determined through orthogonal experiment. The results show that the proper extraction condition for available silicone is the ratio of coal gangue, limestone, sodium carbonate, and caustic soda at 1：0.5：0.1：0.05, calcination temperature at 700 ℃, and calcination time at 2 h. In this condition, the available silicone content can be more than 19.65%.

Extraction,Physiochemical Properties and Antibacterial Activities of Polysaccharides from Auricularia auricular

[Objective] To explore the optimal conditions for extracting polysaccharide from Auricularia auricular, and to study its physiochemical properties and antibacterial activities. [ Method] The extraction conditions for Auricularia auricular polysaccharides were optimized by orthogonal test, and its physiochemical characteristics and antagonistic activities on bacteria and molds were tested. I-Result] The optimized condition was with sample to liquid ratio of 1 ： 50, temperature of 90 ℃ and extraction time of 2.5 h. Under the optimized condition, the yield of pelysaccharide was 7.3%, with polysaccharide content of 77.81%. Containing aldose and amylase, the polysaccharides of Auncu/aria auricular was soluble in water. The inhibitory effect on bacteria was significantly stronger than on molds that the minimum diameter of inhibition zone for bacteria is 12.7 mm, while 7.9 mm for the molds. [ Conclusion] This study provides scientific basis for the development and utilization of Auricularia auricular polysaccharides.

Optimization of Extracting Technology for Essential Oil from Elsholizia densa Benth

[Objective] The study aims to optimize the extracting technology conditions of essential oil from Elsholtzia densa Benth. [Method] Essential oil was extracted from E. densa Benth using steam distillation, and the effects of four extracting factors (grain size of the medicinal herb, ultrasonic time, soaking time and ratio of the material to liquid) on the yield of essential oil extracted from E. densa Benth were analyzed through the orthogonal test. [Result] The optimized extraction process of essential oil from E. densa Benth was as follows: grain size of the medicinal herb 50 mesh, ultrasonic time 12 min, being soaked in the water for 6 h, and ratio of the material to liquid 1∶16 g/ml. Under the conditions, the average extracting rate of the essential oil was 0.407%. [Conclusion] The optimized extraction process of essential oil from E. densa Benth was simple and practicable, and its extracting rate was higher.

高效液相色谱法测定多种维生素矿物质片中维生素B1的含量

研究多种维生素矿物质片中维生素B_(1)含量测定的最佳提取工艺。利用高效液相色谱法鉴别并定量分析多种维生素矿物质片中的维生素B_(1)。以多种生素矿物质片为材料,维生素B_(1)的含量为评价指标。以盐酸溶液的浓度,提取时间,液料比为因素,设计正交试验优化选出最佳提取工艺。结果显示,1mol/L盐酸溶液50mL,提取30min所得样品中维生素B_(1)含量最高。