EN
The marine eustigmatophycean microalga Nannochloropsis (Monallantus) salina Hibberd was cultivated in a batch culture in the presence of various concentrations (0, 25, 50, 75 and 100%) of an aqueous extract of diesel fuel oil in order to assess the influence of the pollutant on the growth and certain physiological responses of the microalga. The growth data revealed a significant negative effect of the various pollutant concentrations on the algal cell number (p≤0.05). However, at the midlogarithmic growth phase (day 8), the algal cells were analysed for chlorophyll a, β-glucan, amino acid pool, C/N ratio and elemental composition. According to our results, N. salina was significantly affected by the pollution with regard to the different physiological parameters examined, and this significance may be negative, positive or variable. The effect of the pollutant on cellular β-glucan and the total amount of amino acids was negative;h owever, the composition of the cellular amino acid pool remained unaffected. A positive effect of the pollutant on cellular chl a and the C/N ratio was observed. In addition, the pollutant showed variable effects on the composition of different elements, as shown by energy-dispersive X-ray microanalysis. Also, an existence correlation between different elements was statistically reported.