AME prepress abstract  -  DOI: https://doi.org/10.3354/ame01910

Effects of abiotic and biotic factors on Vibrio harveyi ATCC 14126T survival dynamics in seawater microcosms

Maite Orruño*, Claudia Parada, Elixabet Ogayar, Vladimir R. Kaberdin, Inés Arana

*Email: maite.orruno@ehu.es

ABSTRACT: The ability of marine bacteria to adequately respond to environmental abiotic and biotic stressors ensures their thriving in diverse aquatic ecosystems. Here we showed that Vibrio harveyi interaction with natural microbiota could greatly reduce the number of vibrios and this effect was dependent on temperature. In contrast, the impact of abiotic stress factors was less hostile and primarily affected V. harveyi morphology and its physiological state. Although exposure to oligohaline environment (0.5‰) and nutrient limitation led to a rapid and irreversible loss of V. harveyi culturability, higher salinities (15‰ to 35.5‰) induced transition to the viable but nonculturable (VBNC) state and cell size reduction in a temperature-dependent manner. Namely, while low temperature (4ºC) caused a marked loss of culturability resulting in a dominant VBNC population, higher temperatures (12°C, 20°C and 30°C) affected bacterial culturability to a lesser extent, but resulted in shorter cells after prolonged incubation, especially at 20°C and 30°C. In summary, our results define temperature as a key factor that influences V. harveyi physiology, morphology and persistence in aquatic systems.