title: Variation in coastal Antarctic microbial community composition at sub-mesoscale: spatial distance or environmental filtering?
abstract: Spatial environmental heterogeneity influences diversity of organisms at different scales. Environmental filtering suggests that local environmental conditions provide habitat-specific scenarios for niche requirements, ultimately determining the composition of local communities. In this work, we analyze the spatial variation of microbial communities across environmental gradients of sea surface temperature, salinity and photosynthetically active radiation and spatial distance in Fildes Bay, King George Island, Antarctica. We hypothesize that environmental filters are the main control of the spatial variation of these communities. Thus, strong relationships between community composition and environmental variation and weak relationships between community composition and spatial distance are expected. Combining physical characterization of the water column, cell counts by flow cytometry, small ribosomal subunit genes fingerprinting and next generation sequencing, we contrast the abundance and composition of photosynthetic eukaryotes and heterotrophic bacterial local communities at a submesoscale. Our results indicate that the strength of the environmental controls differed markedly between eukaryotes and bacterial communities. Whereas eukaryotic photosynthetic assemblages responded weakly to environmental variability, bacteria respond promptly to fine-scale environmental changes in this polar marine system.
authors.affiliation: Center for Genomics and Bioinformatics, Faculty of Sciences, Universidad Mayor, Camino La Pirámide 5750, Santiago 8580745 Chile.
authors.forename: Mario
authors.initials: M
authors.lastname: Moreno-Pino
authors.affiliation: Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331150, Chile Millennium Institute of Ocenography. Cabina 7, Barrio Universitario s/n, Concepción 4030000, Chile.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: De la Iglesia
authors.affiliation: Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, Valdivia 5090000, Chile Centro de Investigación FONDAP: Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Campus Isla Teja, Valdivia 5090000, Chile.
authors.forename: Nelson
authors.initials: N
authors.lastname: Valdivia
authors.affiliation: Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331150, Chile Millennium Institute of Ocenography. Cabina 7, Barrio Universitario s/n, Concepción 4030000, Chile Department of Oceanography, Universidad de Concepción, Cabina 7, Barrio Universitario s/n, Concepción 4030000, Chile.
authors.forename: Carlos
authors.initials: C
authors.lastname: Henríquez-Castilo
authors.affiliation: CREA - Centro Regional de Estudios Ambientales, Universidad Católica de la Santísima Concepción, Av. Colón 2766, Talcahuano 4270789, Chile.
authors.forename: Alexander
authors.initials: A
authors.lastname: Galán
authors.affiliation: Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331150, Chile Center for Climate and Resilience Research (CR), Blanco Encalada 22002, Santiago 8370449, Chile.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Díez
authors.affiliation: Center for Genomics and Bioinformatics, Faculty of Sciences, Universidad Mayor, Camino La Pirámide 5750, Santiago 8580745 Chile nicole.trefault@umayor.cl.
authors.forename: Nicole
authors.initials: N
authors.lastname: Trefault
mesh_terms: D000864:Antarctic Regions; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D044822:Biodiversity; D017753:Ecosystem; D059014:High-Throughput Nucleotide Sequencing; D062312:Islands; D054712:Salinity; D012623:Seawater / Q000737:chemistry / Q000382:microbiology*
keywords: Antarctica; community composition; environmental filtering; microbial community; spatial variation; submesoscale