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固体表面上生物膜的形成是细菌生存和向营养物质定位的一个必要过程。细菌在固体表面上的固着是生物膜形成的重要初始阶段,不同数量的生物聚合物的产生控制着固着过程。这些外细胞聚合物的形成决定于生长条件和基质种类。本文应用多种方法讨论了细菌在不同矿物表面上固着机理,其中包括Zete电位测定、接触角测定、FTIR光谱研究和透射扫描电镜研究。应用P多黏杆菌(Paenibacilluspolymyxa)及方解石和石英作为研究对象。Zeta电位测定结果表明,细菌作用使方解石带更多的负电荷,而使石英表面带更多的正电荷。接触角测量结果表明,细菌处理使石英表面更疏水,而使方解石表面更亲水。有意思的是,不同生长条件下的细胞表面组成决定于它们所接近的矿物。FTIR光谱结果表明,在石英中生长的P多黏杆可产生更多的表面蛋白质,而在方解石中生长的细菌可产生更多的表面多糖。透射扫描电镜分析发现,Bromfield介质中生长的细胞周围有黏液层存在,而方解石中生长的细胞被结构很好的皮囊多糖所包裹,相反地,石英中生长的细胞周围既没有皮囊,也没有黏液层存在。浮选和絮凝试验表明,细菌细胞及其代谢物处理强化了方解石的絮凝过程,而类似的生物处理促进了石英的分散。试验还证明,氧化亚铁硫杆菌对闪锌矿和方铅矿可浮性的影响不同。在制定从低品位有用矿石中经济地提取金属的高效、环境友好的生物加工技术时,细菌处理对不同矿物基质的选择性作用是很有用的。
The formation of biofilm on the solid surface is a necessary process for the survival of the bacteria and the positioning of the nutrients. Bacteria colonization on a solid surface is an important initial stage of biofilm formation. The production of different numbers of biopolymers controls the fixation process. The formation of these extracellular polymers depends on the growth conditions and the type of matrix. In this paper, a variety of methods to discuss bacteria immobilization mechanism on different mineral surfaces, including the Zete potential measurement, contact angle determination, FTIR spectroscopy and transmission electron microscopy studies. Paenibacillus polymyxa and calcite and quartz were used as research objects. Zeta potential measurements show that bacterial action causes more negative charge on the calcite band and more positive charge on the quartz surface. Contact angle measurements show that bacterial treatment makes the quartz surface more hydrophobic and the calcite surface more hydrophilic. Interestingly, the cell surface composition under different growth conditions depends on the minerals they are close to. The results of FTIR spectroscopy showed that P-sticks grown in quartz produced more surface protein, while bacteria grown in calcite produced more surface polysaccharides. Transmission electron microscopy revealed that mucus layers were present around cells grown in Bromfield medium and that cells grown in calcite were surrounded by well-structured skin polysaccharides. Conversely, there was neither skin nor mucus in the surrounding cells grown in quartz Layers exist. Flotation and flocculation tests showed that bacterial cells and their metabolites enhanced the flocculation of calcite while similar biological treatments promoted the dispersion of quartz. The test also showed that the effect of Thiobacillus ferrooxidans on floatability of sphalerite and galena varied. Bacterial treatment is useful for the selective action of different mineral matrices in the development of efficient, environmentally friendly bio-processing techniques for the economical extraction of metals from low-grade, useful ores.