Microbial richness in sandy-silty soil Tunisia and its role in arid zone fertilization

Arid zone are stressful environments, typified by alkaline soils low in organic matter, with biologically limiting extremes in water availability, temperature, and UV radiation. This study aims to analyze the microbial diversity of forest soil and its evolution considering climate change in a typical Mediterranean forest of cork oak (Quercus suber L.) and its importance in arid soil fertilization. The investigation was conducted in forest at north-western Tunisia. The study of the quality of the forest soil was based on physicochemical (pH, C, N, EC...) and microbiological (fungi and bacteria) analyses. A collection of strains has been isolated and identified morphologically (form, gram ...) and biochemically (enzymatic activity: catalase, oxidase ...). According to the results obtained, the forest soil has a pH of about 5.03 ± 0.2, C/N ratio 39.82±1.02. The count and fungi, non-filamentous and non-filamentous bacteria on solid soil show a great diversity that confers the fertility of the soil. An important number of strains of actinomycetes (45 isolates) and non-filamentous bacteria (82 isolates) showing distinctive morphological characteristics. The isolates enzymatic activity showed an important value. These obtained results give an idea on the microbe diversity that can be used in the field of bio-fertilization of poor microbial structure soils as the arid zones and oasis system.