Cellular nutrient content measured with the nuclear microprobe and toxins produced by Dinophysis norvegica (Dinophyceae) from the Trondheim fjord (Norway)

• Dinophysis norvegica is a commonly occurring dinoflagellate species and a producer of diarrhetic shellfish poisons. Natural samples were collected from Trondheim fjord, Norway, to analyse nutrient (O, C, N, P) and toxin (dinophysitoxins [DXTs], okadaic acid [OA], pectenotoxins [PTXs]) content in D. norvegica cells. Nutrient and toxin analyses were also carried out on cells grown under nutrient-sufficient and nutrient-deficient conditions to determine how intracellular nutrient and toxin content varied under different nutrient availability conditions. Nutrient analyses were conducted using nuclear microprobe techniques that can accurately analyse single cells, and toxin analyses were carried out using liquid chromatography and mass spectroscopy. The intracellular carbon, nitrogen and phosphorus content in individual cells varied greatly, and intracellular C:N:P ratios showed that the cells were both N- and P-deficient when compared to the Redfield ratio. The ideal N:P ratio in the media for D. norvegica was found to be below the Redfield ratio, but intracellular ratios did not show a clear relationship with those in the media. N:P ratios of D. norvegica were higher than expected, which is likely due to their phagotrophy on zooplankon. The highest toxin values found were traces of PTX2, 24.72 pg PTX2SA cell(-1), 2.19 pg DTX1 cell(-1), and 1.01 pg OA cell(-1). However, we found no clear relationship between the content of intracellular nutrients and toxins.

Subject headings

NATURVETENSKAP  -- Fysik -- Subatomär fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Subatomic Physics (hsv//eng)

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Keyword

Dinophysis

Diarrhetic shellfish poisoning

Elemental cellular content

Mixotrophy

Nuclear microprobe

Nutrient ratios

Nutrients

Trondheim

fjord

Dinophysis

Akvatisk ekologi

Publication and Content Type

art (subject category)

ref (subject category)