The effect of suboptimal concentration and the exclusion of nitrogen and phosphorus from the medium on β-carotene accumulation by Dunaliella salina Teod. cells, culture growth dynamics, and the uptake of these nutrients under favorable conditions for cell division values of salinity, illumination, and temperature were investigated. Phosphorus exclusion (KH₂PO₄ concentration less than 0.2 mg/L) at suboptimal nitrogen concentrations insertion favored twice more β-carotene accumulation and culture growth than both nutrients’ exclusion or nitrogen exclusion (KNO₃ concentration less than 0.1 mg/L) at suboptimal concentrations of phosphorus. Keeping suboptimal concentrations of both nutrients in the medium (from 20 mg/L KNO₃ and 4 mg/L KH₂PO₄) significantly stimulated culture growth but suppressed carotenogenesis. Keeping constant concentrations of phosphorus in the medium at a level of 45 mg/L of KH₂PO₄ at suboptimal nitrogen concentrations or its exclusion inhibited both culture growth and carotenogenesis. Nitrogen and phosphorus uptake by D. salina cells was maximal at the beginning of growth and proportional to the concentrations of these nutrients in the medium. Mutual dependence of nitrogen and phosphorus uptake of their concentrations was absent. The data obtained may support the specificity of nitrogen and phosphorus depletion effects on the metabolism of D. salina cells. The possible reasons of incompatibility of different investigators data on carotenogenesis induction in D. salina are discussed.

Keywords: Dunaliella salina, β-carotene, nitrogen, phosphorus

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