采集我国地带性土壤山东泰山天外村棕壤,分离提取粗胶体(0.2-2μm)和细胶体(<0.2μm),对两部分胶体进行去有机质和不去有机质处理,得到0.2-2μm含有机质粘粒、0.2-2μm去有机质粘粒、小于0.2μm含有机质粘粒和小于0.2μm去有机质粘粒。以上述不同类型的棕壤胶体、蒙脱石、羟基铝-蒙脱石复合物,高岭石和针铁矿为实验材料,研究了DNA在土壤胶体和矿物表面的吸附解吸行为和结合机制、固定态DNA的稳定性和细胞转化、固定态质粒DNA的PCR扩增以及土壤胶体和矿物对微生物代谢活性的影响,获得如下主要结果:
1.运用吸附和解吸等化学方法和现代仪器分析手段如衰减全反射傅立叶变换红外光谱(ATR/FTIR)、圆二色光谱(CD)、荧光光谱、微量热分析技术,系统探讨了恒电荷土壤活性颗粒表面DNA吸附、解吸及固定的特点,基本揭示了DNA分子在不同类型土壤活性颗粒表面的结合机制。DNA在土壤胶体和矿物表面的最大吸附量顺序为:蒙脱石(?)去有机质细粘粒>含有机质细粘粒>高岭石>去有机质粗粘粒>含有机质粗粘粒。体系pH从2.0增加到5.0,DNA在含有机质粘粒和蒙脱石表面的吸附量显著降低,...
Typical zonal soil such as Brown soil was sampled from Tianwai village, Taishan,Shandong province in China. Two soil colloidal components i.e. fine clay (<0.2μm) andcoarse clay (0.2-2μm) were separated by centrifugation. The two treatments applied tofine and coarse clays were organic matter left on the samples (organic clays) and organicmatter removed from the samples by H_2O_2 (inorganic clays). Brown soil was divided intofour types of clays: coarse organic clay (0.2-2μm, organo-mineral complexes...