Microbe Profile: Durusdinium trenchii: a thermotolerant coral symbiont

Durusdinium trenchii is a unicellular dinoflagellate in the family Symbiodiniaceae, a diverse group of photosynthetic microalgae known for forming symbiotic relationships with cnidarians and other reef organisms. Notably, this species displays exceptional tolerance to heat stress, enabling it to persist within the coral gastrodermis and often dominate symbiont communities under elevated temperatures. D. trenchii can confer increased thermal tolerance and reduced bleaching susceptibility to corals, though frequently with trade-offs in host growth and calcification. Its resilience has been linked to genome duplication, photoprotective mechanisms and characteristic lipid profiles. Its unique molecular traits, host generalist nature, ecological flexibility and increasing prevalence in warming oceans underscore the importance of this microbe in coral reef responses to climate change.