It is with great excitement that I get to post that our manuscript on cultivating members of the microbial majority using an artificial seawater medium is finally out! This manuscript represents the hard work of not just myself, but Dr. Thrash, our undergraduates (past and present), and Austen Webber. Over the last two years, I have traveled to sites along the Gulf of Mexico collecting water for cultivation experiments (> 2000 miles traveled, > 4500 well inoculated). From the sites along the coasts of Louisiana, we have cultivated organisms from the Gulf of Mexico representing many important marine clades: SAR11, SAR116, OM43, OM252, Roseobacter, and many more. While isolating these organisms is important, it is also important to isolate organisms that represent abundant taxa within your source water. We compared OTUs from community sequencing of the source water to our isolate sequences to demonstrate that our method frequently captured some of the most abundant organisms in the system.
This work also represents the first instance where many of these clades were isolated from the Gulf of Mexico, and importantly, on an artificial seawater medium. While high throughput, dilution-to-extinction culturing using natural seawater has been highly successful, we hope that this new approach using artificial seawater media will help more researchers cultivate important microorganisms without the hassle of collecting large volumes of natural seawater and needing a boat.
If you have any questions, please feel free to contact us! We are more than willing to answer any questions you may have. You can check out our list of organisms isolated so far HERE!
Emily 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.
Celeste 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.
Last week David and I got up early enough to duck a series of storms coming through the region for some sunny sampling on Lake Borgne. This also saw the maiden voyage of a new Thrash Lab capital acquisition, the R/V Schipperke. We put in at Campo’s Marina, toodled out to a site past the old fort (these are commonplace in this region), and took measurements and water collections. The water was almost fresh, with a salinity ~5. David used these to inoculate the latest high throughput cultivation experiment since Mike Henson is currently at the C-MORE summer course. Here are some photos.