Microbial distribution and turnover in Antarctic microbial mats highlight the relevance of heterotrophic bacteria in low-nutrient environments
Por:
Valdespino-Castillo, Patricia M., Cerqueda-Garcia, Daniel, Espinosa, Ana Cecilia, Batista, Silvia, Merino-Ibarra, Martin, Tas, Neslihan, Alcantara-Hernandez, Rocio J., Falcon, I, Luisa
Publicada:
1 sep 2018
Resumen:
Maritime Antarctica has shown the highest increase in temperature in the
Southern Hemisphere. Under this scenario, biogeochemical cycles may be
altered, resulting in rapid environmental change for Antarctic biota.
Microbes that drive biogeochemical cycles often form biofilms or
microbial mats in continental meltwater environments. Limnetic microbial
mats from the Fildes Peninsula were studied using high-throughput 16S
rRNA gene sequencing. Mat samples were collected from 15 meltwater
stream sites, comprising a natural gradient from ultraoligotrophic
glacier flows to meltwater streams exposed to anthropogenic activities.
Our analyses show that microbial community structure differences between
mats are explained by environmental NH4+, NO3-, DIN, soluble reactive
silicon and conductivity. Microbial mats living under ultraoligotrophic
meltwater conditions did not exhibit a dominance of cyanobacterial
photoautotrophs, as has been documented for other Antarctic limnetic
microbial mats. Instead, ultraoligotrophic mat communities were
characterized by the presence of microbes recognized as heterotrophs and
photoheterotrophs. This suggests that microbial capabilities for
recycling organic matter may be a key factor to dwell in ultra-low
nutrient conditions. Our analyses show that phylotype level assemblages
exhibit coupled distribution patterns in environmental oligotrophic
inland waters. The evaluation of these microbes suggests the relevance
of reproductive and structural strategies to pioneer these psychrophilic
ultraoligotrophic environments.
Filiaciones:
Valdespino-Castillo, Patricia M.:
Inst Invest Biol Clemente Estable, Unidad Microbiol Mol, Montevideo 11600, Uruguay
Cerqueda-Garcia, Daniel:
Falcon, Luisa, I, Univ Nacl Autonoma Mexico, Inst Ecol, Lab Ecol Bacteriana, Cdmx 04510, Mexico
Espinosa, Ana Cecilia:
Univ Nacl Autonoma Mexico, Inst Ecol, LANCIS, Cdmx 04510, Mexico
Batista, Silvia:
Inst Invest Biol Clemente Estable, Unidad Microbiol Mol, Montevideo 11600, Uruguay
Merino-Ibarra, Martin:
Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Unidad Acad Ecol & Biodiversidad Acuat, Cdmx 04510, Mexico
Tas, Neslihan:
Lawrence Berkeley Natl Lab, Earth & Environm Sci Area, Berkeley, CA 94720 USA
Alcantara-Hernandez, Rocio J.:
Univ Nacl Autonoma Mexico, Inst Geol, Cdmx 04510, Mexico
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