Wildifire effects on forest soil microbial community structure assessed by comparative molecular analyses of DNA (extracellular vs. intracellular) and RNA

In relation to climate change effects on forest ecosystem, the frequency of fire events represents one of the most drastically events that are expected to increase in the future, not only in the Mediterranean basin but also in not traditionally interested areas. The fire impact on soil ecosystem has been only recently considered in relation to its relevance on the forest ecosystem response. These effects are very complex depending on the soil physical, chemical and biological properties. This study aims to assess the fire effect on microbial community diversity and activity of a forest soil by DNA- and RNAmolecular screening (PCR-DGGE). Burned and adjacent unburned soils site to Orentano, near Pisa, Italy were sampled three days and ten months after the wildfire event. Concerning the DNA fingerprinting we analyzed both extracellular and intracellular DNA fractions of soil metagenome. These data were combined with those of cDNA arising from the soil total RNA pool. The study of soil microbial activity has been implemented by expression analyses of betaglucosidase and protease genes.