Marine Microbes: Kim B. Ritchie's Research on Coral Reefs and Beneficial Bacteria

Dr. Ritchie has studied corals and associated microbes for over 25 years and currently is focused on marine bacteria that live within corals. She explains for listeners

• The ecology of coral reefs and what causes coral "bleaching,"
• Why several marine bacteria associated with corals form a protective microbiome through antibiotic production, and
• How other microbes in the ocean, including bacterial associations of sharks and rays, also have interesting stories to tell.

Kim B. Ritchie is an associate professor of genetics and prokaryotic cell biology at the University of South Carolina Beaufort. She tells listeners how her interest in marine bacteria and microbes in the ocean began as an undergrad studying corals and continues in her current research. She explains that corals are animals that have an obligate symbiosis with a single-celled photosynthetic organism called a dinoflagellate. These algae live inside the cells of the corals and give the reefs their colors. Temperature increases cause the corals to expel this algae, leading to what is called coral bleaching and eventually death.

She is studying the symbiosis of bacteria and coral and the protective nature of this microbiome. She began by studying the microbial shifts by looking at what type of bacteria are present under normal non-stressful conditions and how that shifts as temperature increases, when more of a pathogenic ecosystem develops. She goes into more detail of why this happens, namely that these beneficial bacteria produce antibiotics that deter the harmful marine bacteria and microbes in the ocean. She noticed in warmer months the corals lose that antibiotic bacteria and gain pathogenic bacteria. She explains her study methods in more detail as well as the implications, and describes other studies she's working on regarding ancient marine microbes such as the healing properties of sharks and rays.

For more, see her website at www.uscb.edu/academics/academic_departments/school-of-science-and-mathematics/natural_sciences/research/kim-ritchie.html. Available on Apple Podcasts: apple.co/2Os0myK