Dr. Christina Kellogg, Environmental Microbiologist
On board the NOAA vessel Nancy Foster is Dr. Christina Kellogg, from the US Geological Survey. Dr. Kellogg runs a lab in St. Petersburg, Florida, at the USGS Coastal and Marine Science Center. Chris grew up in the Caribbean where she learned to love the marine environment. After college she wasn’t sure what she was going to do, just that she did not want to go to medical school like so many of her peers.
While composing her graduate school admission essay, she wrote that she was amazed to learn that a drop of seawater holds over a million viruses. Other topics that interested her included using bacteria for bioremediation of oil spills. She found the sudden decrease in the number of long spine sea urchins in the 1980s puzzling.
After realizing that her interests all converged in marine microbiology, she entered graduate school at the University of South Florida where her thesis work was on the genetic diversity in marine bacteriophages and their bacterial hosts, with a side trip into DNA repair mechanisms in bacteria. This somewhat esoteric subject caused her to veer into a postdoc in something she thought might be more practical, developing new drug targets in the human pathogenic yeast, Candida albicans. But the biotech dollar signs could not hold her, and she began to work at the USGS as a Mendenhall Postdoctoral Fellow, returning to her roots as an Environmental Microbiologist.
Her first project was determining whether bacteria and fungi from the dust storms in the Sahara could survive crossing the Atlantic. To the surprise of many, they do survive. The press picked up these findings and turned them into headlines “Pathogens in Dust from Africa Cross the Atlantic.”
She soon began to work with coral and became the head of her own lab. First working with tropical corals, her focus has now turned to the deep-water corals of the Atlantic. It appears that corals have unique populations of bacteria growing on their surface, at least at the genus level, and sometimes at the level of species. Few if any of the coral species in the canyons we will visit have been characterized in terms of their associated microbes. This is a complex relationship with plenty of work to be done.
Some of the questions that remain are, 1) Do some bacteria find the mucus secreted by coral to be attractive, while others are repelled or even attacked by anti-bacterial substances? 2) Once a bacteria is established in the coral mucus, how does that change the environment, allowing or inhibiting different species of bacteria to grow there? 3) Does having a healthy coating of bacteria help keep pathogens away from the coral?
Some of the other things the bacteria are doing may be more directly beneficial to the coral, such as nitrogen fixation, reduction of iron, and recycling of nutrients. The bacteria may be able to break down components of “marine snow” that would be unavailable to the coral, and thereby make nutrients available.
Because of the crowded conditions on this trip, Chris will be unable to culture bacteria directly from the coral we collect. Instead, she will preserve pieces of coral in RNALater and later use high-throughput DNA sequencing to determine as well as she can the identities of the bacteria growing on the corals.
Another project that will go on the landers is designed to determine what type of surfaces promote the kinds of biofilm that are later colonized by coral. You can read more about this research at http://oceanexplorer.noaa.gov/explorations/12midatlantic/logs/aug16/aug16.html.