典型土壤矿物对枯草芽胞杆菌自然转化的影响

Effects of typical soil minerals on natural transformation of Bacillus subtilis

采用化学吸附方法与紫外微量DNA浓度检测技术,考察恒电荷土壤活性颗粒吸附及固定胞外DNA(质粒pHTG)的特点,同时研究不同矿物对枯草芽胞杆菌发生自然转化的影响。不同种类的矿物颗粒对质粒pHTG的吸附能力不同,其中以针铁矿最强,高岭石次之,蒙脱石则为三者中最弱的。同时矿物的存在会对枯草芽胞杆菌的自然转化率产生一定的影响,其转化效率随着矿物质量浓度的增加而降低,当矿物质量浓度由0mg/mL增加至8mg/L时,与对照相比,转化效率下降2个数量级。

The adsorption of extracellular DNA(a designed plasmid,pHTG)on the soil active particles and the influences of the minerals on the natural transformation of Bacillus subtilis were investigated with chemical adsorption and trace DNA detection analysis.The trace DNA was mixed with the three clay mineral solutions to clarify the adsorption characteristic of pHTG on permanent-charge soil active particles.The results showed that the adsorption of pHTG were dependent on the minerals.Different minerals had different adsorption.The maximum amount of pHTG adsorbed was in the order of goethite>kaolinite>montmorillonite.Minerals reduced the natural transformation.The transformation efficiency was decreased with the increase of mineral concentration.When mineral concentration increased from 0.0 mg/mL to 8.0 mg/mL,the transformation efficiency was reduced in two orders of magnitude.Montmorillonite significantly decreased the transformation,while goethite had the least influence.