soil crust metagenome Raw sequence reads

In this study, we expand upon the biogeography of biological soil crusts (BSCs) and provide high-resolution insights into the microbial diversity along the vertical BSC column structure, and across a transect of increasing BSC surface coverage in the central Mojave Desert, California. Next generation sequencing reveals a bacterial community structure that is phylogenetically distinct among BSCs in the southwestern United States. Distribution of major phyla in the BSC topsoils included Cyanobacteria (33 ± 8%), Proteobacteria (26 ± 6%), and Chloroflexi (12 ± 4%), with Phormidium being the numerically dominant genus. Furthermore, BSC subsurfaces contained Proteobacteria (23 ± 5%), Actinobacteria (20 ± 5%), and Chlorflexi (18 ± 3%), with an unidentified genus from Chloroflexi (AKIW781, order) being numerically dominant. Across the transect, changes in the phylogenetic distributions, including multiple biochemical and geochemical trends, positively correlated to increasing BSC surface coverage. These trends included increased (a) diversity among the Cyanobacteria and low-abundant genera, (b) species-level diversity in the topsoil, (c) species-level differentiation between the topsoil and subsurface, (d) intracellular ATP abundances and catalase activities, and (e) enrichments in clay, silt, and varying elements, including S, Mn, Co, As, & Pb, in the BSC topsoils. Moreover, these combined trends suggest that BSC successional maturation and colonization are inhibited by metals/metalloids, including B, Ca, Ti, Mn, Co, Ni, Mo, and Pb. In sum, these results suggest that BSCs across the transect represent successional-type stages that exhibit increasing phylogenetic diversity, metabolic activities, and capacity to restructure the soil.