@article {4152,
	title = {Drivers of protistan community autotrophy and heterotrophy in chemically stratified Antarctic lakes},
	journal = {Aquatic Microbial Ecology},
	volume = {82},
	year = {2019},
	month = {01/2019},
	pages = {225 - 239},
	abstract = {<p>Single-celled, eukaryotic microorganisms, known as protists, are responsible for 2 important, yet opposing, metabolic activities within aquatic food webs. They are major primary producers and highly active predators in marine and fresh water systems. While genomics has accelerated in recent years for this taxonomically diverse group, our understanding of the metabolic capabilities of most protists remains limited. It is also poorly understood how protist trophic mode is affected by biotic and abiotic factors, and therefore it is difficult to predict how events such as global climate change will affect the balance between autotrophic and heterotrophic activities in protist communities. To address open questions regarding how protist metabolic versatility is influenced by their environment, we characterized the potential for carbon fixation versus organic carbon degradation using enzymatic assays (RubisCO and β-D-glucosaminidase, respectively) within the water columns of ice-covered lakes in McMurdo Dry Valleys (MDV), Antarctica. Steep physical and chemical gradients in the water columns, microorganism domination and minimal allochthonous inputs makes the MDV lakes uniquely suited to investigate environment-microbe interactions. Spatial trends in RubisCO and β-D-glucosaminidase activities were lake-specific and vertically stratified within the water columns. Moreover, bottom-up drivers controlling the activity of C-fixation vs. organic C-degradation among the MDV protist communities were distinct between the upper photic vs. the deep, aphotic zones. We conclude that differential controls over major C-cycling enzymes have important implications on the influence of environmental change on the carbon and nutrient cycles in the MDV lakes.</p>},
	keywords = {LTER-MCM, Antarctic lakes, Aquatic protists, Autotrophy, Heterotrophy, McMurdo Dry Valleys, RubisCO, β-D-glucosaminidase},
	issn = {0948-3055},
	doi = {10.3354/ame01891},
	url = {https://www.int-res.com/abstracts/ame/v82/n3/p225-239/},
	author = {Li, Wei and Dolhi-Binder, J and Cariani, ZE and Rachael M. Morgan-Kiss}
}
@article {4186,
	title = {Influence of environmental drivers and potential interactions on the distribution of microbial communities from three permanently stratified Antarctic lakes},
	journal = {Frontiers in Microbiology},
	volume = {10},
	year = {2019},
	month = {05/2019},
	abstract = {<p>The McMurdo Dry Valley (MDV) lakes represent unique habitats in the microbial world. Perennial ice covers protect liquid water columns from either significant allochthonous inputs or seasonal mixing, resulting in centuries of stable biogeochemistry. Extreme environmental conditions including low seasonal photosynthetically active radiation (PAR), near freezing temperatures, and oligotrophy have precluded higher trophic levels from the food webs. Despite these limitations, diverse microbial life flourishes in the stratified water columns, including Archaea, bacteria, fungi, protists, and viruses. While a few recent studies have applied next generation sequencing, a thorough understanding of the MDV lake microbial diversity and community structure is currently lacking. Here we used Illumina MiSeq sequencing of the 16S and 18S rRNA genes combined with a microscopic survey of key eukaryotes to compare the community structure and potential interactions among the bacterial and eukaryal communities within the water columns of Lakes Bonney (east and west lobes, ELB, and WLB, respectively) and Fryxell (FRX). Communities were distinct between the upper, oxic layers and the dark, anoxic waters, particularly among the bacterial communities residing in WLB and FRX. Both eukaryal and bacterial community structure was influenced by different biogeochemical parameters in the oxic and anoxic zones. Bacteria formed complex interaction networks which were lake-specific. Several eukaryotes exhibit potential interactions with bacteria in ELB and WLB, while interactions between these groups in the more productive FRX were relatively rare.</p>},
	keywords = {LTER-MCM, Aquatic protists, environmental drivers, heterotrophic bacteria, interactions, McMurdo Dry Valley lakes},
	doi = {10.3389/fmicb.2019.01067},
	url = {https://www.frontiersin.org/articles/10.3389/fmicb.2019.01067/full},
	author = {Li, Wei and Rachael M. Morgan-Kiss}
}
