AME 83:109-118 (2019)  -  DOI: https://doi.org/10.3354/ame01910

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

KEY WORDS: Vibrio harveyi · Temperature · Predation · Viable but nonculturable