Bacterial Succession within an Ephemeral Hypereutrophic Mojave Desert Playa Lake |
| |
Authors: | Jason B Navarro Duane P Moser Andrea Flores Christian Ross Michael R Rosen Hailiang Dong Gengxin Zhang Brian P Hedlund |
| |
Institution: | (1) School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154-4004, USA;(2) Division of Earth and Ecosystem Sciences, Desert Research Institute, Las Vegas, NV 89119, USA;(3) Nevada Water Science Center, United States Geological Survey, Carson City, NV 89701, USA;(4) Department of Geology, Miami University, Oxford, OH 45056, USA |
| |
Abstract: | Ephemerally wet playas are conspicuous features of arid landscapes worldwide; however, they have not been well studied as
habitats for microorganisms. We tracked the geochemistry and microbial community in Silver Lake playa, California, over one
flooding/desiccation cycle following the unusually wet winter of 2004–2005. Over the course of the study, total dissolved
solids increased by ∽10-fold and pH increased by nearly one unit. As the lake contracted and temperatures increased over the
summer, a moderately dense planktonic population of ∽1 × 106 cells ml−1 of culturable heterotrophs was replaced by a dense population of more than 1 × 109 cells ml−1, which appears to be the highest concentration of culturable planktonic heterotrophs reported in any natural aquatic ecosystem.
This correlated with a dramatic depletion of nitrate as well as changes in the microbial community, as assessed by small subunit
ribosomal RNA gene sequencing of bacterial isolates and uncultivated clones. Isolates from the early-phase flooded playa were
primarily Actinobacteria, Firmicutes, and Bacteroidetes, yet clone libraries were dominated by Betaproteobacteria and yet
uncultivated Actinobacteria. Isolates from the late-flooded phase ecosystem were predominantly Proteobacteria, particularly
alkalitolerant isolates of Rhodobaca, Porphyrobacter, Hydrogenophaga, Alishwenella, and relatives of Thauera; however, clone libraries were composed almost entirely of Synechococcus (Cyanobacteria). A sample taken after the playa surface was completely desiccated contained diverse culturable Actinobacteria
typically isolated from soils. In total, 205 isolates and 166 clones represented 82 and 44 species-level groups, respectively,
including a wide diversity of Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Gemmatimonadetes, Acidobacteria,
and Cyanobacteria.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|