Bacterial Community Structure and Patterns of Diversity in the Sediments of Mountain Rock Basins from a National Park

Abstract

Bacterial microbiomes influence global carbon and nutrient cycling as the environment changes. Rain-fed rock basins are ephemeral aquatic systems, potentially subject to extreme environmental stress, that can host a wide variety of biological communities, including bacteria. However, bacterial communities are barely described in these habitats. Here we provide a detailed description on the occurrence, diversity and distribution patterns of the bacterial communities within and between rain-fed granite mountain rock basins located in the Sierra de Guadarrama National Park, Spain, using high-throughput sequencing of 16S RNA. We recovered a highly diverse community consisting of 3174 operational taxonomic units (OTUs) belonging to 32 phyla. In total, 50% of OTUs were shared among basins and 6–10% were basin-exclusive OTUs, suggesting a robust global bacterial metacommunity colonizes the basins. The existence of 6% replicate-exclusive OTUs and the fact that at least four replicates were required to catalogue 90% of the basin bacterial community emphasized the heterogeneity of these habitats. Both environmental filtering and random dispersal are likely to be involved in the arrangement of the bacterial communities. The taxa identified in this study are versatile in metabolism, and some have biotechnological potential. The taxonomic affiliation of many of the OTUs found suggests that rain-fed rock basins could be a resource for mining novel bacterial biocompounds.