effects of elevated carbon dioxide levels on a Vibrio sp. isolated from the deep-sea

Introduction The effect of oceanic CO₂ sequestration was examined exposing a deep-sea bacterium identified as Vibrio alginolyticus (9NA) to elevated levels of carbon dioxide and monitoring its growth at 2,750 psi (1,846 m depth). Findings The wild-type strain of 9NA could not grow in acidified marine broth below a pH of 5. The pH of marine broth did not drop below this level until at least 20.8 mM of CO₂ was injected into the medium. 9NA did not grow at this CO₂ concentration or higher concentrations (31.2 and 41.6 mM) for at least 72 h. Carbon dioxide at 10.4 mM also inhibited growth, but the bacterium was able to recover and grow. Exposure to CO₂ caused the cell to undergo a morphological change and form a dimple-like structure. The membrane was also damaged but with no protein leakage.