Examination of the Bacterial Biodiversity of Coastal Eroded Surface Soils from the Padza de Dapani (Mayotte Island)

To better understand microbial populations present in atypical soil environments, and to discern any relations between these environments and their bacterial communities, we examined the "Padza de Dapani" on the island of Mayotte off the east coast of Africa. This area is not a true (hot) desert, but resembles one in many places due to extensive soil erosion. We collected surface soil samples from five different sites of the Padza de Dapani in Mayotte. We examined bacterial biodiversity using pyrosequencing of PCR-amplified 16S V1-V3 rDNA sequences from total extracted DNA. Our results show that in the acidic (pH 4.6-6), oligotrophic (organic carbon; 0.1-0.7 g/kg of soil) and mineralized (Fe: 18 g/100 g; Al: 12 g/100 g) Dapani Padza soil samples, members of the Actinobacteria and Proteobacteria phyla dominated the bacterial communities, as was also observed in samples from Saudi Arabia hot desert sands. Interestingly, members belonging to the genera Acinetobacter, Arthrobacter and Bacillus were also found to be very abundant in our samples. These were also seen in hot Asian deserts sand samples, such as those from the Gobi (Mongolia) and Taklamaken (China) deserts, thus possibly pointing to microbial populations characteristic of denuded soils.