Cultivating members of the microbial majority

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.

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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!

Henson, Michael W., David M. Pitre, Jessica Lee Weckhorst, V. Celeste Lanclos, Austen T. Webber, and J. Cameron Thrash. (2016). Artificial seawater media facilitates cultivating members of the microbial majority from the Gulf of Mexico. mSphere 1(2). doi: 10.1128/mSphere.00028-16. (Undergraduate authors) Supplementary Information.

Some associated press became available on May 1st. Check out Becoming Acculturated, by Jeffrey M. Perkel.

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.

Sampling Lake Borgne

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.

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On the way through the cut
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David taking YSI readings

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First run on the Barataria Transect

Yesterday I joined Jim Lee and Charlie Milan to help them execute sampling for the monthly Barataria Transect, one of Eugene Turner’s projects. His lab has been doing this transect, monthly, since 1994 to monitor water chemistry and some of the biology that occurs across this contiguous estuarine system. Over the years, various other sampling has been done, including work on the Macondo oil spill and toxic algal blooms. They brought me along so I could collect samples at the beginning of the transect in support of our microbial community survey of the Southern Louisiana coastline and our high-throughput culturing activities. I also brought my camera.

Grand Isle at sunset, facing southeast. Some oil platforms are visible in the distance.
Grand Isle at sunset, facing southeast. Some oil platforms are visible in the distance.
The quaint Grand Isle Suites where we stayed overnight. Our LSU van and 19' whaler are visible in front.
The quaint Grand Isle Suites where we stayed overnight. Our LSU van and 19′ whaler are visible in front.
Calibrating the YSI
Calibrating the YSI
The Sand Dollar Motel, where we launched
The Sand Dollar Motel, where we launched
An early sampling station
An early sampling station
Early segments of the transect are mostly water with faraway marsh
Early segments of the transect are mostly water with faraway marsh
Oil production in the northwest corner of Lake Salvador
Oil production in the northwest corner of Lake Salvador
Coolers and action-packers make the sampling go 'round
Coolers and action-packers make the sampling go ’round
A charming camp near one of our sampling sites.
A charming camp near one of our sampling sites.

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Jim doing turbidity measurements, old school
Jim doing turbidity measurements, old school

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HWY 90, also known as station 30.
HWY 90, also known as station 30.
Old HWY 90
Old HWY 90
Some of the local architecture
Some of the local architecture
Me and Jim
Me and Jim
A lonely cypress in Lac des Allemandes
A lonely cypress in Lac des Allemandes
The entrance to Bayou Chevreuil
The entrance to Bayou Chevreuil
Beautiful Bayou Chevreuil
Beautiful Bayou Chevreuil
Bayou Chevreuil
Bayou Chevreuil

-jct