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Nicole Ratib Receives a Simons Postdoctoral Fellowship!

Nicole is currently finishing her Ph.D. with Steve Finkel at USC, where she studied, among other things, the genomic signatures of evolution in a long-term extended stationary phase experiment (1200 days!) in E. coli. She wanted to switch gears for her postdoc and work on marine microorganisms. Her proposal, “Quantifying dormancy rates and controlling factors in the globally abundant bacterioplankton SAR11”, has been funded as a Simons Foundation Postdoctoral Fellowship in Marine Microbial Ecology. Nicole will employ a variety of advanced techniques, including fluorescence-activated cell-sorting and nanoSIMS, to investigate dormancy in one of the most important marine microbial clades, near and dear to my heart, SAR11. We’re thrilled for Nicole to join the lab, starting in January, to begin this important work. Congratulations Nicole!

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Emily successfully defends her Honors Thesis

Emily Nall (far left in the photo), who has been an undergraduate researcher in the lab for her entire time at LSU, defended her Honors Thesis yesterday entitled Physiological and Genomic Characterization of a Novel Isolate from the OM252 Clade of Gammaproteobacteria. Emily has been working steadily on this project for a couple years. She has used comparative genomics to reconstruct the metabolism of strain LSUCC0096, tested a number of physiological parameters, some of which were predicted from the genome, and has examined the organism’s distribution throughout our coastal data as well as the Tara Oceans data. The next step will be getting the final pieces of this project together for publication. It’s important to note that Emily also funded part of this project herself through a Louisiana Sea Grant Undergraduate Research Opportunities Program (UROP) Fellowship. We’re very proud of you Emily and wish you all the best after graduation!

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Our LD12 cultivation manuscript has been published

Our paper on the cultivation and genomics of the freshwater SAR11 strain LSUCC0530 has been published online in the ISME Journal (Here). The SAR11 LD12 lineage evolved to colonize freshwater ecosystems, and, like its marine cousins, occurs as one of the most abundant freshwater bacterioplankton worldwide. Strain LSUCC0530 represents the first cultivated representative of the LD12 clade and presented the Thrash lab with an unprecedented opportunity to provide new insights into the important evolutionary processes behind marine-freshwater transitions. Specifically, we demonstrated the capacity of strain LSUCC0530 to grow in salinities up to 5, provided evidence for LD12 ecotype differentiation based on temperature, and developed a hypothesis on how the loss of key genetic functions enabled the SAR11 clade to transition into fresh water. This work is only the beginning of our exploration into the SAR11 LD12 clade and its marine-freshwater transition, so be on the look out for more data soon!

If you have any questions or want to know more about LSUCC0530, please feel free to contact us! We are more than willing to answer any questions you may have.

Henson, Michael W.,  V. Celeste Lanclos, Brant C. Faircloth, and J. Cameron Thrash. (2018) Cultivation and genomics of the first freshwater SAR11 (LD12) isolate. The ISME Journal. AOP.

 

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Thrash lab presentations at #ASMicrobe

Mike, Celeste, and Emily will all be presenting at the 2017 ASM Microbe conference in New Orleans this coming weekend. Here is the info to find them:

Saturday (6/3)
Poster Session: AES11 – Freshwater and Marine Microbiology I
Time: 12:15 PM – 2:15 PM

Cultivation and Ecology of Novel SAR11 Taxa from Coastal Louisiana Waters (#700), V. Celeste Lanclos

Metabolic and Physiological Flexibility in a Coastal Isolate from the OM252 Clade of Gammaproteobacteria (#712), Emily Nall

Sunday (6/4)
Symposium: 425 – Culturing the Unculturable in a Sequencing Age (Room 352)
Time: 2:30 PM – 5:00 PM

Fresh and Salty: Cultivating Bacteria from the Coast of Louisiana, Michael W. Henson

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Emily and Celeste present at LSU Discover Day

IMG_7074Emily presented her LA Sea Grant-funded work to characterize one of our coastal isolates from the OM252 clade, LSUCC0096. She showed this organism has remarkable salinity tolerance, and can grow under chemolithoautotrophic conditions, a feature that was predicted from genome analysis.

 

 

 

 

IMG_7071Celeste presented results of her experiment to enrich for microorganisms that could utilize fulvic acids as their sole carbon source. She compared her work to that of former lab member Jessica Weckhorst who performed a similar experiment with humic acids. These are both extremely important fractions of the marine DOC pool.