Modification of a commercial DNA extraction kit for safe and rapid recovery of DNA and RNA simultaneously from soil, without the use of harmful solvents

摘要

An optimized method, based on the coupling of two commercial kits, is described for the extraction of soil nucleicacids, with simultaneous extraction and purification of DNA and RNA following a cascade scheme and avoidingthe use of harmful solvents. The protocol can monitor the variations in the recovery yield of DNA and RNA fromsoils of various types.- The quantitative version of the protocol was obtained by testing the starting soil quantity, the grindingparameters and the final elution volumes, in order to avoid saturation of both kits.- A first soil-crushing step in liquid nitrogen could be added for the assessment of fungal parameters.- The protocol was efficient on different tropical soils, including andosol, while their high contents of clays,including poorly crystalline clays, and Fe and Al oxides usually make the nucleic acid extraction more difficult.- The RNA recovery yield from the previous tropical soils appeared to correlate better to soil respiration thanDNA, which is positively influenced by soil clay content.