Welcome to the Learman Environmental Microbiology Lab at Central Michigan University.
The lab focuses on understanding how microbes (single strains or microbial communities) control biogeochemical cycles in various environments, ranging from oceans, lakes, to sediments. The lab utilizes a range of techniques in microbial ecology, physiology, genomics, and geochemistry.
Former Students
Jessica Zehnpfennig -
M.S. Biology (2020)
Thesis title, "Spatial and temporal analysis of dark microbial community metabolism in the Atlantic Ocean."
Dean J. Horton -
Ph.D. Earth & Ecosystem Science (2018)
Dissertation title, “Examining the impacts of natural and anthropogenic disturbances on microbial communities in freshwater ecosystems.”
Shanker Tamang -
M.S. Biology (2017)
Thesis title, “Determining the influence of carbon and nitrogen metabolism on Mn(II) oxidation.”
Michael W. Henson - M.S. Biology (2014), Thesis title, “Connecting Function and Ecology: Defining Bacterial Cr(VI) Pathways in the Environment and Laboratory”
Amanda Lis - Biomedical Sciences Major (2019)
Victoria Hewitt - Environmental Science Major (2019)
Allison Brookshier - Biochemistry Major (2019)
Zahra Ahmad - B.A. Journalism Major and Biology Minor (2018)
Miranda Hengy - B.S. Biology Major (2017)
Adam Byrne - B.S. Environmental Health and Safety Major (2016)
James Dunn - B.S. Biochemistry Major (2015)
Sarah Phillips - B.S. Biomedical Science Major (2015)
Sam Strahl -
B.S. Geology Major (2015)
Nathan Young - B.S. Biology Major (2014)
Ethan Wologo - B.S. Geology Major (2013)
Assessing and enhancing the natural attenuation potential of Great Lake ecosystems to remediate hydrocarbon spills
Great Lakes coastal wetlands play a unique role in the entire Great Lakes ecosystem as they filter out sediment and nutrients, provide habitats for fish and wildlife, and generate many millions of dollars per year in ecosystem services (improve water quality, mitigate flood damage, provide recreational opportunities, serve as nursery habitat for sport and commercial fisheries, etc.). Nearly 50% of these vital ecosystems have been lost to development and some of the most pristine coastal wetland that remain today are located in the Straits of Mackinac. The Straits are important to not only the Great Lakes ecosystem, but to the economy of the region as they provide recreational opportunities, are critical to the sport and commercial fisheries, and play a major role in the transportation of goods and resources. One such resource, crude oil, has received corporate, government, and public attention due to the risk potential of an accidental spill. Crude oil is an essential resource so understanding possible remediation strategies is key to its utilization and transport. The current work is examining the natural remediation potential (natural attenuation) of Great Lakes coastal wetlands and its connection to microbial community structure and genetic degradation potential (metagenomics).
Exploring microbial metabolism in marine sediments from Antarctica
The changing climate in Antarctica has the potential to initiate a domino effect that could impact ecosystems from the continental ice sheets to the deep biosphere. As Western Antarctica is one of the fastest warming locations on Earth, its changing climate will not only lead to an increase in sea-level but will also alter regional water temperature and chemistry. These changes will inevitably impact the microorganisms that inhabit these environments and govern the biogeochemical cycles (e.g. carbon, nitrogen, sulfur) that are essential for this thriving ecosystem. This research is using metagenomic analysis to examine these marine sediments to identify the metabolic functional potential to drive crucial biogeochemical cycles.
Central Michigan University Great Lakes Research Experiences for Undergraduates
This Central Michigan University Great Lakes Research Experiences for Undergraduates program, funded by the National Science Foundation and the College of Science and Engineering, supports the training of 8 students for 10 weeks during the summers of 2019-2022. For more information, please visit this site:
https://www.cmich.edu/colleges/se/cmubs/CMUREU/Pages/default.aspx
Impacts of diel light intensity changes on marine microbial life in productive ocean communities
Our current understanding of the complex and dynamic ocean ecosystem is limited due to single time of day sampling “snapshots”. Therefore, to examine how light/temperature and other daily variant conditions impact microbial communities in ocean waters, the lab has sampled the productive coastal water at various locations, depths, and times throughout the day (pre-sunrise to post sunset). DNA and RNA from the samples will be examined using high-throughput sequencing techniques to identify the microorganisms present in ocean communities (DNA) and also evaluate the community metabolism (RNA, metatranscriptomics). These data will be applied to determine how the diversity of these communities changes as well as how shifts in gene expression throughout the day are potentially impacting biogeochemical cycles.
Biogeochemistry and microbial community structure in Great Lakes wetlands
The biogeochemical cycling of greenhouse gases (such as N2O and CH4) and essential nutrients (e.g. carbon and nitrogen) are catalyzed by a diverse group microorganisms within wetlands. There are greater than 2,000 coastal wetlands in the Laurentian Great Lakes, despite a 50% reduction driven by anthropogenic habitat destruction. In one project, we are exploring these critical ecosystems to better understand the microbial communities and biogeochemical processes they govern. In a second project, we are examining how natural forces, such as diel O2 fluctuations, can impact community structure and function.
GelC MS/MS DataRaw data for Learman and Hansel, 2014
Roseobacter sp. AzwK-3b,
Raw dataRuegeria sp. TM1040,
Raw dataAntarctic sediment OTU tableOTU table for Learman et al., 2016
OTU_table.xlsxAntarctic sediment Supplemental Materials for all R code usedFrom Learman et al., 2016
ANT_16S_R.txtANT_18S_R.txt
Learman et al., 2016, Supplementary MaterialsClick to view

Deric, Mike Henson, and James Dunn at the annual ASM meeting

Sarah Phillips (middle) working with K-12 teachers at our summer GeoMicrobiology workshop

K-12 teachers from Beal City, Mt. Pleasant, and Harbor Beach setting up some Winogradsky columns at our summer GeoMicrobiology workshop

Deric and Miranda Hengy sampling water on Lake Geneserath (Beaver Island, MI)

Deric and CMUBS students looking over some Lake Michigan benthic sediments taken from the R/V Chippewa. Smell that metabolism

Sarah presenting at the CMU’s Student Research and Creative Endeavors Exhibition (2015)

Dean sampling wetlands on Beaver Island, MI example

Shanker sampling wetlands on Beaver Island, MI

Mike in the field at Poyang Lake, China

Zahra presenting at the Spring 2016 Michigan ASM Meeting

Sam presenting at the CMU's Student Research and Creative Endeavors Exhibition (2015)

Michigan ASM Meeting

Mike and Ethan looking over their MI-ASM poster

Ethan presenting at the Capital building (Lansing, MI)

Deric presenting at a symposium in China

Deric in the field at Poyang Lake, China

Deric sampling a phytoplankton bloom in coastal New Jersey