Comparative metagenomic analysis reveals mechanisms for stress response in hypoliths from extreme hyperarid deserts

• Published in: Genome Biology and Evolution
• Main Authors: Le, Phuong Thi, Makhalanyane, Thulani P., Guerrero, Leandro Demián, Vikram, Surendra, Van De Peer, Yves, Cowan, Don A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press
• Subjects: ANTARCTICA; BIOMES; COMPARATIVE METAGENOMICS; DESERTS; HYPOLITHS; NAMIB DESERT; SOILS; STRESS RESPONSE; https://purl.org/becyt/ford/1.6; https://purl.org/becyt/ford/1; Antarctic; The Antarctic; Miers; Miers Valley; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/11336/79410

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 twometagenomeswere identified. The Antarctic hypolithicmetagenome displayed a high number of sequences assigned to sigma factors, replication,recombination andrepair, translation, ribosomal structure,andbiogenesis. In contrast, theNamibDesert metagenome showed a high abundance of sequences assigned to carbohydrate transport and metabolism. Metagenome data analysis also revealed significantdivergence inthe geneticdeterminantsof aminoacidandnucleotidemetabolismbetween 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. Fil: Le, Phuong Thi. University of Pretoria; Sudáfrica. Vlaams Instituut voor Biotechnologie; Bélgica. University of Ghent; Bélgica Fil: Makhalanyane, Thulani P. University of Pretoria; Sudáfrica Fil: Guerrero, Leandro Demián. University of Pretoria; Sudáfrica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería ...