Biogeography of bacterial communities exposed to progressive long-term environmental change

• Published in: The ISME Journal
• Main Authors: Logares, Ramiro, Lindström, Eva S., Langenheder, Silke, Logue, Jürg B., Paterson, Harriet, Laybourn-Parry, Johanna, Rengefors, Karin, Tranvik, Lars, Bertilsson, Stefan
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: International Society for Microbial Ecology 2013
• Subjects: Environmental change; Bacteria; Long-term; Pyrosequencing; Salinity; Antarctica; Antarctic; Antarc*
• Online Access: http://hdl.handle.net/10261/96140; https://doi.org/10.1038/ismej.2012.168

12 pages, 5 figures The response of microbial communities to long-term environmental change is poorly understood. Here, we study bacterioplankton communities in a unique system of coastal Antarctic lakes that were exposed to progressive long-term environmental change, using 454 pyrosequencing of the 16S rDNA gene (V3-V4 regions). At the time of formation, most of the studied lakes harbored marine-coastal microbial communities, as they were connected to the sea. During the past 20 000 years, most lakes isolated from the sea, and subsequently they experienced a gradual, but strong, salinity change that eventually developed into a gradient ranging from freshwater (salinity 0) to hypersaline (salinity 100). Our results indicated that present bacterioplankton community composition was strongly correlated with salinity and weakly correlated with geographical distance between lakes. A few abundant taxa were shared between some lakes and coastal marine communities. Nevertheless, lakes contained a large number of taxa that were not detected in the adjacent sea. Abundant and rare taxa within saline communities presented similar biogeography, suggesting that these groups have comparable environmental sensitivity. Habitat specialists and generalists were detected among abundant and rare taxa, with specialists being relatively more abundant at the extremes of the salinity gradient. Altogether, progressive long-term salinity change appears to have promoted the diversification of bacterioplankton communities by modifying the composition of ancestral communities and by allowing the establishment of new taxa.© 2013 International Society for Microbial Ecology All rights reserved Financial support for this work was provided by the Swedish Research Council for Environment, Agricultural Sciences, and Spatial Planning (FORMAS) via Uppsala Microbiomics Centre (UMC) (granted to SB and LT), the Swedish Research Council (granted individually to SB, ESL and KR), the Marie Curie Intra-European Fellowship (PIEFGA-2009-235365, EU) and ...