贺纪正-华中农大201511-2课稿.ppt

Establishing SIP method for AOA and AOB investigation 12C incubation 13C incubation AOA AOB Abundance of amoA gene in CsCl density gradients after 12C- /13C-CO2 incubation AOA/AOB amoA 基因在不同CsCl 密度梯度上的DGGE图谱 Day 14 Day 28 Day 14 Day 28 AOB 1.65 1.73 Buoyant density (g ml - 1 ) 13 CO 2 12 CO 2 Day 14 Day 28 Day 14 Day 28 1.65 1.73 Buoyant density (g ml - 1 ) 13 CO 2 12 CO 2 AOA 1.65 1.73 Buoyant density (g ml - 1 ) Day 14 Day 28 Day 14 Day 28 1 2 1 2 1 2 1 2 1 1 2 1 2 2 2 13 CO 2 12 CO 2 1.65 1.73 Buoyant density (g ml - 1 ) Day 14 Day 28 Day 14 Day 28 1 2 1 2 1 2 1 2 1 1 2 1 2 2 2 13 CO 2 12 CO 2 Day 14 Day 28 Day 14 Day 28 1 1 2 2 1 1 2 2 1 2 1 2 1 1 2 1 2 2 2 13 CO 2 12 CO 2 1 这些结果表明，AOA能够固定13C-CO2进行自养生长，是该土壤中硝化作用的主要驱动者；首次为古菌参与土壤硝化作用提供了直接证据 Zhang et al. 2010, PNAS, 107, 17240-17245. Soil Sampling pH (H2O) pH (KCl) HZ 4.20 3.29 YH 4.21 3.34 QJ 4.36 3.66 QY 4.43 3.87 TY 4.47 3.89 Part I: Soil microcosm incubation HZ YH QJ QY TY Control 50 ppm DCD 10 g soil 120 ml Sample at 0, 7, 15, 30 day DCD, nitrification inhibitor dicyandiamide (C2H4N4) Treatments 5% 12CO2 5% 12CO2 + 50 ppm DCD 5% 13CO2 5% 13CO2 + 50 ppm DCD Part II: DNA-SIP incubation Net Nitrification activity Relative abundance of amoA gene in CsCl gradient AOA AOA AOA AOA AOA AOB AOB Buoyant density (g ml-1) 12C 13C 13C+DCD Day 0 Day 15 Day 30 AOB Light Heavy DGGE analysis of amoA genes Group I.1a-associated Group I.1b 该研究揭示出酸性土壤中氨氧化古菌对硝化作用的主导贡献 IF 9.267 Soil sampling 65 soil samples pH gradients 3.7 ~ 8.5 Habitat types Forest Agricultural Grassland Tea orchard Hu et al., 2013, SBB, JSS Mechanism Discussion Availability of substrate ammonia NH3; pH influences NH3 availability and the growth of AOB; Different affinity of AOA and AOB to ammonia. He et al., 2012, Soil Biology Biochemistry Nitrogen source for ammonia oxidizers Nitrogen resources AOA and AOB AOA and AOB Availability of ammonia under acidic conditions pKa = 9.25; 25?C, Water Content: 2