title: Microbial Characterization of Qatari Barchan Sand Dunes.
abstract: This study represents the first characterization of sand microbiota in migrating barchan sand dunes. Bacterial communities were studied through direct counts and cultivation, as well as 16S rRNA gene and metagenomic sequence analysis to gain an understanding of microbial abundance, diversity, and potential metabolic capabilities. Direct on-grain cell counts gave an average of 5.3 ± 0.4 x 105 cells g-1 of sand. Cultured isolates (N = 64) selected for 16S rRNA gene sequencing belonged to the phyla Actinobacteria (58%), Firmicutes (27%) and Proteobacteria (15%). Deep-sequencing of 16S rRNA gene amplicons from 18 dunes demonstrated a high relative abundance of Proteobacteria, particularly enteric bacteria, and a dune-specific-pattern of bacterial community composition that correlated with dune size. Shotgun metagenome sequences of two representative dunes were analyzed and found to have similar relative bacterial abundance, though the relative abundances of eukaryotic, viral and enterobacterial sequences were greater in sand from the dune closer to a camel-pen. Functional analysis revealed patterns similar to those observed in desert soils; however, the increased relative abundance of genes encoding sporulation and dormancy are consistent with the dune microbiome being well-adapted to the exceptionally hyper-arid Qatari desert.
authors.affiliation: Department of Research, Weill Cornell Medical Qatar, Qatar Foundation, Doha, Qatar.
authors.forename: Sara
authors.initials: S
authors.lastname: Abdul Majid
authors.affiliation: Department of Microbiology, Cornell University, Ithaca, New York, United States of America.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Graw
authors.affiliation: Department of Research, Weill Cornell Medical Qatar, Qatar Foundation, Doha, Qatar.
authors.forename: Aspassia D
authors.initials: AD
authors.lastname: Chatziefthimiou
authors.affiliation: Department of Microbiology, Cornell University, Ithaca, New York, United States of America.
authors.forename: Hanh
authors.initials: H
authors.lastname: Nguyen
authors.affiliation: Department of Research, Weill Cornell Medical Qatar, Qatar Foundation, Doha, Qatar.
authors.forename: Renee
authors.initials: R
authors.lastname: Richer
authors.affiliation: Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, United States of America.
authors.forename: Michel
authors.initials: M
authors.lastname: Louge
authors.affiliation: Department of Research, Weill Cornell Medical Qatar, Qatar Foundation, Doha, Qatar.
authors.forename: Ali A
authors.initials: AA
authors.lastname: Sultan
authors.affiliation: Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America.
authors.forename: Patrick
authors.initials: P
authors.lastname: Schloss
authors.affiliation: Department of Microbiology, Cornell University, Ithaca, New York, United States of America.
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Hay