Physiological responses of the eustigmatophycean Nannochloropsis salina to aqueous diesel fuel pollutionAuthor(s): Nagwa Gamal-El-Din Mohammady | Yean-Chang Chen | Abd-El-Ruhman Aly El-Mahdy | Rania Farag Mohammad
Journal: Oceanologia ISSN 0078-3234
Volume: 47; Issue: 1; Start page: 75; Date: 2005;
Keywords: Diesel fuel pollution | Physiological responses | Nannochloropsis salina
The marine eustigmatophycean microalga Nannochloropsis(Monallantus) salina Hibberd was cultivated in a batchculture 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 influenceof the pollutant on the growth and certain physiological responses of themicroalga. The growth data revealed a significant negative effect of thevarious pollutant concentrations on the algal cell number(p ≤ 0.05). However, at the mid-logarithmic 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 ourresults, N. salina was significantly affected by the pollution withregard to the different physiological parameters examined, and thissignificance may be negative, positive or variable. The effect of thepollutant on cellular β-glucan and the total amount of amino acidswas negative; however, the composition of the cellular amino acid poolremained unaffected. A positive effect of the pollutant on cellular chl aand the C/N ratio was observed. In addition, the pollutant showed variableeffects on the composition of different elements, as shown byenergy-dispersive X-ray microanalysis. Also, an existencecorrelation between different elements was statistically reported.