Soil microbial carbon uptake characteristics in relation to soil management
1990
Anderson, T.H. | Gray, T.R.G.
The kinetics of glucose uptake by soil microbial communities in 16 different soils (7 under monocultures and 9 under crop rotations) differing in microbial biomass content, % Corg, pH and clay content were investigated at 22 degrees C. The mean Vmax value of microbial biomasses under monoculture, was 0.27 microgram Cgluc.microgram-1 Cmic.h-1 range 0.18-0.44), twice as high as the mean value of Vmax of microbial biomasses under rotations (0.13 microgram Cgluc, range 0.07-0.19). Mean values of Km were 714 microgram Cgluc and 290 microgram Cgluc.g-1 soil, respectively. These differences were highly significant (P = 0.001, based on SE) and could not be related to particle size distribution of the soils, pH or Corg. A Michaelis-Menten type uptake response was apparent over the total range of glucose concentrations used (45.4-1453.3 microgram Cgluc.g-1 soil) for microbial biomasses under rotation while the majority of microbial biomasses under monocultures showed a similar response only at low glucose concentrations. A different uptake mechanism appeared to be involved at higher glucose concentrations (similar to diffusion) in monocultures soils.
显示更多 [+] 显示较少 [-]