Quantitative isolation of microbial DNA from the different types of soils of natural and agricultural ecosystems

A novel procedure was developed for direct quantitative isolation of microbial DNA from soil. This technique was used to evaluate microbial DNA pools in soils of contrasting types (chernozems and brown forest soils) under different anthropogenic loads. A strong correlation was found between microbial biomass and DNA contents in soils of different types (R2 = 0.799). The ratio of soil CO2 emission rate to the amount of extractable DNA in the soil was shown to reflect physiological state of the soil microbial community; this ratio can be used as an ecophysiological parameter similarly to the metabolic quotient qCO2.