Metabolic Capability and Phylogenetic Diversity of Mono Lake during a Bloom of the Eukaryotic Phototroph Picocystis sp. Strain ML

Algal blooms in lakes are often associated with anthropogenic eutrophication; however, they can occur without the human introduction of nutrients to a lake. A rare bloom of the alga sp. strain ML occurred in the spring of 2016 at Mono Lake, a hyperalkaline lake in California, which was also at the a...

Full description

Saved in:
Bibliographic Details
Published in:Applied and environmental microbiology 2018-11, Vol.84 (21)
Main Authors: Stamps, Blake W, Nunn, Heather S, Petryshyn, Victoria A, Oremland, Ronald S, Miller, Laurence G, Rosen, Michael R, Bauer, Kohen W, Thompson, Katharine J, Tookmanian, Elise M, Waldeck, Anna R, Loyd, Sean J, Johnson, Hope A, Stevenson, Bradley S, Berelson, William M, Corsetti, Frank A, Spear, John R
Format: Article
Language:English
Subjects:
Algae
Algal blooms
Anaerobic microorganisms
Anthropogenic factors
Biological activity
Chloroplasts
Drought
Environmental Microbiology
Eutrophication
Gene sequencing
Lake sediments
Lakes
Light levels
Microbial activity
Microorganisms
Nutrients
Oxygen
Oxygen production
Photosynthesis
Photosystem I
Photosystem II
Phylogeny
Relative abundance
rRNA
Studies
Sulfate reduction
Sulfates
Water
Water column
Water depth
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Algal blooms in lakes are often associated with anthropogenic eutrophication; however, they can occur without the human introduction of nutrients to a lake. A rare bloom of the alga sp. strain ML occurred in the spring of 2016 at Mono Lake, a hyperalkaline lake in California, which was also at the apex of a multiyear-long drought. These conditions presented a unique sampling opportunity to investigate microbiological dynamics and potential metabolic function during an intense natural algal bloom. We conducted a comprehensive molecular analysis along a depth transect near the center of the lake from the surface to a depth of 25 m in June 2016. Across sampled depths, rRNA gene sequencing revealed that -associated chloroplasts were found at 40 to 50% relative abundance, greater than values recorded previously. Despite high relative abundances of the photosynthetic oxygenic algal genus , oxygen declined below detectable limits below a depth of 15 m, corresponding with an increase in microorganisms known to be anaerobic. In contrast to previously sampled years, both metagenomic and metatranscriptomic data suggested a depletion of anaerobic sulfate-reducing microorganisms throughout the lake's water column. Transcripts associated with photosystem I and II were expressed at both 2 m and 25 m, suggesting that limited oxygen production could occur at extremely low light levels at depth within the lake. Blooms of appear to correspond with a loss of microbial activity such as sulfate reduction within Mono Lake, yet microorganisms may survive within the sediment to repopulate the lake water column as the bloom subsides. Mono Lake, California, provides a habitat to a unique ecological community that is heavily stressed due to recent human water diversions and a period of extended drought. To date, no baseline information exists from Mono Lake to understand how the microbial community responds to human-influenced drought or algal bloom or what metabolisms are lost in the water column as a consequence of such environmental pressures. While previously identified anaerobic members of the microbial community disappear from the water column during drought and bloom, sediment samples suggest that these microorganisms survive at the lake bottom or in the subsurface. Thus, the sediments may represent a type of seed bank that could restore the microbial community as a bloom subsides. Our work sheds light on the potential photosynthetic activity of the halotolerant alga sp. strai
ISSN:0099-2240
1098-5336
DOI:10.1128/AEM.01171-18