Diversity of the Bacterial Community of Three Soils Revealed by Illumina-Miseq Sequencing of 16S rRNA Gene in the South of Brazzaville, Congo

The study was conducted on three soils (MFILOU, SNR and ORSTOM) at the south of Brazzaville in Congo. The aim of the work was to study the composition and diversity of the soil microbial community. Microbial diversity was assessed using the Miseq-Sequencing. The results showed that microbial diversity was represented by 1289 OTUs assigned to the Bacteria (1282 OTUs), Fungi (2 OTUs), Viridiplantae (3 OTUs) and metazoa (2OTUs) domain with 97% of similarity. The 1282 bacterial OTUs were affiliated with 12 phyla, 31 classes, 59 orders, 122 families, 288 genera et 521 species for all sites. The Proteobacteria (45.59%-29.92%), Firmicutes (27.27%-7.35%), Acidobacteria (16.74%-10.15%), Actinobacteria (12.35%-5.07%) and Nitrospirae are the most abundant common phyla for the three sites. The most dominant common classes were Alphaproteobacteria (38.87%-24.77%), Bacilli (27.20%-6.95%), Acidobacteria (16.47%-7.59%), Actinobacteria (12.35%-5.07%) and Nitrospira (9.81%-1.78%). The most abundant common orders for the 3 sites are represented by Rhizobiales (33.96%-20.38%), Bacillales (27.20%-6.95%), Acidobacteriales (16.49%-7.61%), Actinomycetales (10.20%-3.6%) and Nitrospirales (9.81%-1.78%). Bacillaceae (25.37%-5.60%), Acidobacteriaceae (16.49%-7.61%), Bradyrhizobiaceae (10.81%-4.61%), Nitrospiraceae (9.81%-1.78%) and Chitinophagaceae (4.24%-1.59%) were the best distributed common families in the microbial community of the three sites. Bacillus (25.27%-5.56%), the most abundant and common genera were Rhodoplanes (15.48%-5.30%), Bradyrhizobium (10.74%-4.39%), Nitrospira (9.81%-1.78%) and Acidobacterium (8.49%-6.51%). At species level, Rhodoplanes spp. (15.26%-5.10%), Bradyrhizobium spp. (10.59%-4.35%) and Acidobacterium spp. (8.49%-6.51%) were the most common and abundant in the three soils.