High carbon use efficiency in soil microbial communities is related to balanced growth, not storage compound synthesis

Results of this study show that synthesis of storage compounds is not responsible for the observed high CUE. Instead, it is the position-specific CO2 production expected for balanced growth and high CUE that best matches the observed CO2 production pattern in these two soils. Comparison with published studies suggests that the amount of glucose added in this study is too low and the duration of the experiment too short to affect microbial metabolism. We conclude that the hypothesis of high CUE in undisturbed soil microbial communities remains viable and worthy of further testing.