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

• Published in: The ISME Journal
• Main Authors: Logares, R, Lindstrom, ES, Langenheder, S, Logue, JB, Paterson, H, Laybourn-Parry, J, Rengefors, K, Tranvik, L, Bertilsson, S
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2013
• Subjects: Biological Sciences; Microbiology; Microbial Ecology; Antarctic; Antarc*
• Online Access: https://doi.org/10.1038/ismej.2012.168; http://www.ncbi.nlm.nih.gov/pubmed/23254515; http://ecite.utas.edu.au/89595

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 thatwere exposed to progressive long-term environmental change, using 454 pyrosequencing of the 16SrDNA gene (V3V4 regions). At the time of formation, most of the studied lakes harbored marinecoastalmicrobial 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, salinitychange that eventually developed into a gradient ranging from freshwater (salinity 0) to hypersaline(salinity 100). Our results indicated that present bacterioplankton community composition wasstrongly 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 thatthese groups have comparable environmental sensitivity. Habitat specialists and generalists weredetected among abundant and rare taxa, with specialists being relatively more abundant at theextremes of the salinity gradient. Altogether, progressive long-term salinity change appears to havepromoted the diversification of bacterioplankton communities by modifying the composition ofancestral communities and by allowing the establishment of new taxa.