Comparative study of vanillin influence on physiological and biochemical properties of blue-green algae Spiralulina platensis in Zarrouk and Johnson nutritional media

The widespread use of vanillin in food and pharmaceutical industries increases the probability of entering to the waters and its positive or negative effects on growth and life of aquatic algae. Due to the nutritional and medical importance of Spirulina platensis, a blue-green micro-alga, the effect of vanillin on its growth and physiological characteristics was considered in two Zarrouk and Johnson media, on 0, 21, 27 and 33 days of a 42 days period. The highest dry weight was obtained in Zarrouk and then Zarrouk containing vanillin media, whilst the highest growth was observed in Zarrouk and then Johnson media. A positive and strong correlation (R 2=0.94, p<0.01) was observed between the turbidity of suspension at 560 nm with its dry weight. Vanillin reduced growth and dry biomass in all days of sampling, but in contrast increased the amount of lipid and protein in both media. The amounts of chlorophyll a, carotenoids, phycocyanin, allophycocyanin, phycoerythrin, astaxanthin, phenol, carbohydrate and lipid peroxidation were often higher in Johnson medium (without vanillin). Although, the recent medium in most cases induced the maximum cell productions, but Zarrouk medium, compared to the Zarrouk containing vanillin medium, showed some inverse results. In general, although vanillin led to a reduction in algal growth and biomass, but in cases where valuable products such as antioxidants, pigments, lipid compounds, protein, carbohydrates and phenols are considered, it can be used as an inducing factor of production.