Air-Drying, Cooling and Freezing for Soil Sample Storage Affects the Activity and the Microbial Communities from Two Mediterranean Soils

The selection of soil storage conditions must take into account the diversity of soils and their environmental characteristics, because different soil types may vary in their physical and chemical characteristics and microbial populations. As a result, identical storage conditions can produce different effects on different soil samples, and understanding the influence of soil storage in respect to the microbial community is essential for further microbial research. In this study, two different characteristics were used to assess the influence of soil processing and storage on two Mediterranean soils: respiratory activity and bacterial community composition in relation to three common storage conditions: air-drying, cooling and freezing. Samples from both soils (a Calcaric Regosol and a Haplic Arenosol) were air-dried or stored at either 4°C or −20°C for 12 months, and a PCR-DGGE analysis was performed to reveal changes in the whole bacterial community, and more specifically in the Firmicutes group, throug...