title: Comparative Metagenomic Analysis Reveals Mechanisms for Stress Response in Hypoliths from Extreme Hyperarid Deserts.
abstract: Understanding microbial adaptation to environmental stressors is crucial for interpreting broader ecological patterns. In the most extreme hot and cold deserts, cryptic niche communities are thought to play key roles in ecosystem processes and represent excellent model systems for investigating microbial responses to environmental stressors. However, relatively little is known about the genetic diversity underlying such functional processes in climatically extreme desert systems. This study presents the first comparative metagenome analysis of cyanobacteria-dominated hypolithic communities in hot (Namib Desert, Namibia) and cold (Miers Valley, Antarctica) hyperarid deserts. The most abundant phyla in both hypolith metagenomes were Actinobacteria, Proteobacteria, Cyanobacteria and Bacteroidetes with Cyanobacteria dominating in Antarctic hypoliths. However, no significant differences between the two metagenomes were identified. The Antarctic hypolithic metagenome displayed a high number of sequences assigned to sigma factors, replication, recombination and repair, translation, ribosomal structure, and biogenesis. In contrast, the Namib Desert metagenome showed a high abundance of sequences assigned to carbohydrate transport and metabolism. Metagenome data analysis also revealed significant divergence in the genetic determinants of amino acid and nucleotide metabolism between these two metagenomes and those of soil from other polar deserts, hot deserts, and non-desert soils. Our results suggest extensive niche differentiation in hypolithic microbial communities from these two extreme environments and a high genetic capacity for survival under environmental extremes.
authors: Centre for Microbial Ecology and Genomics (CMEG), Department of Genetics, University of Pretoria, Pretoria, South Africa Department of Plant Systems Biology, VIB, Ghent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.
authors: Phuong Thi
authors: PT
authors: Le
authors: Centre for Microbial Ecology and Genomics (CMEG), Department of Genetics, University of Pretoria, Pretoria, South Africa.
authors: Thulani P
authors: TP
authors: Makhalanyane
authors: Centre for Microbial Ecology and Genomics (CMEG), Department of Genetics, University of Pretoria, Pretoria, South Africa.
authors: Leandro D
authors: LD
authors: Guerrero
authors: Centre for Microbial Ecology and Genomics (CMEG), Department of Genetics, University of Pretoria, Pretoria, South Africa.
authors: Surendra
authors: S
authors: Vikram
authors: Centre for Microbial Ecology and Genomics (CMEG), Department of Genetics, University of Pretoria, Pretoria, South Africa Department of Plant Systems Biology, VIB, Ghent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium Bioinformatics Institute Ghent, Ghent University, Technologiepark 927, Ghent Belgium don.cowan@up.ac.za yves.vandepeer@psb.vib-ugent.be.
authors: Yves
authors: Y
authors: Van de Peer
authors: Centre for Microbial Ecology and Genomics (CMEG), Department of Genetics, University of Pretoria, Pretoria, South Africa don.cowan@up.ac.za yves.vandepeer@psb.vib-ugent.be.
authors: Don A
authors: DA
authors: Cowan
mesh_terms: D039903:Actinobacteria / Q000235:genetics / Q000302:isolation & purification; D000864:Antarctic Regions; D041963:Bacteroidetes / Q000235:genetics / Q000302:isolation & purification; D000458:Cyanobacteria / Q000235:genetics / Q000302:isolation & purification; D003889:Desert Climate; D000071251:Extreme Environments; D054892:Metagenome; D064307:Microbiota; D020560:Proteobacteria / Q000235:genetics / Q000302:isolation & purification; D013312:Stress, Physiological
keywords: Antarctica; Namib Desert; biomes; comparative metagenomics; deserts; hypoliths; soils; stress response