Significance of gene variants for the functional biogeography of the near-surface Atlantic Ocean microbiome

Leon Dlugosch,Rolf Daniel,Anja Poehlein,Thomas H Badewien,Bernd Wemheuer,Birgit Pfeiffer,Meinhard Simon

doi:10.1038/s41467-022-28128-8

Abstract

Microbial communities are major drivers of global elemental cycles in the oceans due to their high abundance and enormous taxonomic and functional diversity. Recent studies assessed microbial taxonomic and functional biogeography in global oceans but microbial functional biogeography remains poorly studied. Here we show that in the near-surface Atlantic and Southern Ocean between 62°S and 47°N microbial communities exhibit distinct taxonomic and functional adaptations to regional environmental conditions. Richness and diversity showed maxima around 40° latitude and intermediate temperatures, especially in functional genes (KEGG-orthologues, KOs) and gene profiles. A cluster analysis yielded three clusters of KOs but five clusters of genes differing in the abundance of genes involved in nutrient and energy acquisition. Gene profiles showed much higher distance-decay rates than KO and taxonomic profiles. Biotic factors were identified as highly influential in explaining the observed patterns in the functional profiles, whereas temperature and biogeographic province mainly explained the observed taxonomic patterns. Our results thus indicate fine-tuned genetic adaptions of microbial communities to regional biotic and environmental conditions in the Atlantic and Southern Ocean.

Highlights

Microbial communities are major drivers of global elemental cycles in the oceans due to their high abundance and enormous taxonomic and functional diversity
As prokaryotes are major drivers of global elemental cycles in the oceans due to their high abundance and enormous taxonomic and functional diversity[3], attempts have been made to adopt this concept to microbial communities on global or ocean basin scales[4,5]
Random forest models indicated that biotic variables contributed most to the biogeographic structuring of KO and gene profiles whereas temperature and province explained most of structuring the taxonomic profiles

Summary

Introduction

Microbial communities are major drivers of global elemental cycles in the oceans due to their high abundance and enormous taxonomic and functional diversity. The richness and diversity patterns of the KO and gene profiles suggest that intermediate temperatures and seasonally fluctuating environmental and biotic conditions[24,25] may promote functional (micro) diversification of prokaryotic communities that are more reflected in community function than in taxonomic composition. The taxonomic, KO, and gene profiles of the AOM were structured into distinct clusters, mostly in line with their respective biogeographic provinces or regions with similar hydrographic conditions (Fig. 2g–i, Supplementary Fig. 3).

Results

Conclusion