摘要
采用离子可透过模型和不可透过模型,通过数值拟合的方法计算嗜酸氧化亚铁硫杆菌的表面电荷密度、空间电荷密度、表面电位和道南电位等。Zeta电位测定结果表明:以硫为能源培养的细菌细胞等电点(IEP)高于报道的以亚铁培养的细菌的。运用表面基团离子化模型模拟实验数据得出:以硫培养的嗜酸氧化亚铁硫杆菌的IEP〉2,这主要是由细菌表面蛋白质的氨基电离引起的。采用离子可透过模型分析表明:pH〈5时,细菌表面电位(φ0)和道南电位(φDON)下降较快;细菌表面的pH值等于细胞内的pH(约6-7)后,细菌的φ0和φDon的变化渐缓;计算得到细菌表面的双电层的厚度约为5 nm。细菌表面的双电层将影响浸矿体系中离子迁移和营养物质传输,而细菌彼此表面双电层的相互作用对细菌聚集不利。
The surface charge density,space charge density,surface potential(φ0) and Donnan potential(φDon) on the surface of Acidithiobacillus ferrooxidans cultivated with elemental sulfur(S-A.ferrooxidans) were calculated by numerical simulation using the ion-impenetrable and ion-penetrable models.Zeta potential measurement show that the isoelectric point(IEP) of S-A.ferrooxidans is higher than that of bacterium cultured with Fe2+.It is concluded from fitting data by ionizable surface group model that S-A.ferrooxidans surface probably consists of much proteins,the ionization of amino group of which causes higher IEP(2).The ion-penetrable model reveals that φ0 and φDon decrease rapidly at pH5 but hardly change when pH is 6-7.The thickness of electrical double layer of S-A.ferrooxidans is estimated as 5 nm.The electrical double layer of bacterial cell surface may have significant implications for ions transfer and nutrient transport,but their interaction is unfavorable for bacterial aggration.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2011年第6期1485-1490,共6页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(50874032
21007009
41073060)
全国优秀博士学位论文作者专项资金资助项目(200549)
关键词
双电层
道南电位
离子可透过模型
软颗粒
electrical double layer
Donnan potential
ion-impenetrable model
soft particle