Adenylate energy charge and ATP-to-microbial biomass C ratio in soils differing in the intensity of disturbance

We carried out an 8-days' incubation experiment with three different intensities of soil disturbance to analyse the effects on the ATP-to-microbial biomass C ratio and on the adenylate energy charge (AEC=(ATP+0.5×ADP)/(AMP+ADP+ATP). Single mixing of soil at 50% water holding capacity with a spatula during weighing of the samples into extraction jars at the end of the 8-days' incubation or 8-times repeated daily mixing for 2 min triggered the immediate formation of ATP, increasing both AEC and the ATP-to-microbial biomass C ratio. The energy for this extra ATP produced seems to be mainly derived from an accelerated turnover of C within the microbial biomass. In contrast, 8-days' continuous mixing led to a significant decrease in AEC and ATP-to-microbial biomass C ratio.