茚三酮比色法测定矿物表面吸附浸矿细菌蛋白质含量

Protein content of mineral-adhered bacterium by ninhydrin colorimetric method

为了研究浸矿细菌在矿物表面的吸附量与金属浸出率的关系,必须测定矿物表面吸附的细菌数量.在100℃的水浴中,用0.5mol/L的NaOH溶液消化矿物表面的细菌时间为25min,然后用0.5mol/L的HCl溶液中和至pH=7.0.在2mL中和液中加入1mL茚三酮显色液,在100℃的水浴中加热20min,冷却6min后,在波长为562nm时测定反应产物的吸光值A.吸光值A对应溶液中的蛋白质含量,进而对应着矿物表面吸附细菌的数量.

Biomass of bacterium on mineral surfaces is measured to study the relation between growth of adhered bacterium and metal dissolution. The mineral samples containing adhered bacterium are digested in 0.5 mol/L NaOH in a boiling water bath for 25 min. The digested soup then filtered and the filtrate is neutralised to pH=7 using 0.5 mol/L HCl. Then 1 mL of reagent ninhydrin is added to 2 mL of protein extracted solution and mixed thoroughly. The mixed solution is heated in a boiling water bath for 20 min, then the boiled solution is cooled for 6 min. After development of the color, the absorbance is measured at 562 nm using a UV1100 for the protein content, which provides a measure of the attached cell mass.