Continuous cultures of Pavlova lutheri (Droop) Green were grown under different nutritional and growth conditions, and the photopigment distribution was subsequently determined. Methods used to analyse the light absorption properties of 90% acetone extracts of P. lutheri pigments consisted of both spectrophotometric, i.e. trichromatic and derivative analyses, and high performance liquid cromatrography (HPLC) measurements. Qualitative and quantitative relationships between results obtained with such analytical methods were established. Trichromatic methods produced accurate results only for chlorophyll a, whereas the derivative method offered a valid alternative way of studying the absorption spectra of photosynthetic pigments extracted in acetone, and calculating their concentrations. On the other hand, the ratio of light absorption at 480 and 665 nm by these photopigment extracts proved to be a useful indicator of the nutritional status of P. lutheri. |