The Moroccan Rivers Microbiome

Freshwater rivers play a significant role in preserving the ecosystem, which is beneficial to the communities around them. A differential metagenomic assessment of two freshwater habitats in Morocco was conducted as a pioneering study to decipher Moroccan rivers' microbial diversity and richness. These rivers originate from the Middle Atlas Mountains and are the Moulouya which empties into the Mediterranean Sea, in northeast Morocco, Oum Errabia and Sebou which flow to the Atlantic. Amplicon-based metagenomic DNA targeting the V4V5 region of the 16S rRNA gene was carried out. Water samples were collected on the winter and summer solstices to investigate the impact of seasonal and environmental variation on microbial diversity. The investigation of physicochemical parameters showed high electronic conductivity (EC), chemical oxygen demand (COD), and biological oxygen demand (BOD) at the sampling sites, indicating organic pollution. Bioinformatics analysis identified a high abundance of Proteobacteria, Actinobacteria, and Bacteroidetes phyla, in almost all river sites in both summer and winter seasons. A correlation between the most abundant prokaryotic taxa and physicochemical parameters was performed to assess the effects of pollution on bacterial diversity. Genera such as Acinetobacter, Arcobacter, and Bacteroides were positively correlated with high levels of pollution, which suggest them as bioindicators candidates of pollution in freshwater.