engleski

A New Method in Ecotoxicology: Evaluation of Farming Algae Using the Chlorella test.

Microalgae are important as primary producers in aquatic habitats and present the base of food chains. Algae are gaining attention for their application in aquaculture as a highly sustainable source of useful products. Tracing the effect of toxicants upon them is very important for maximizing nutrient content. Chlorella is a widely used unicellular model in ecotoxicological research. Green algae were maintained on the surface of sterile deep stock agar in tubes (2 g agar, 100 mg KNO3, 1 ml MgSO4 x 7 H2O, 1 ml K2HPO4, 0.1 ml FeCl3, 100 ml dH2O)1. After 14 days they were plated to the newly prepared deep agars in tubes by the platine needle in laminar. The content of one tube was divided and plated to deep agars into 5 new tubes. These were the pre-conditions for the Chlorella test and were its constituent part. In Chlorella test, instead of dH2O, the same amount of aqueous solution of toxicant was put into the agar medium. This is the essence of the Chlorella test method2. Chlorella test of comparative toxicity of iron (iron dextran) was performed on 2 endosymbiotic algae isolated from green hydrae and on 2 related free-living species in three concentrations and compared with control samples. After a short period of time, morphological changes were distinguished macroscopically already. Bleaching of algae was present in particular tubes, as a result of the effect of the toxicant upon the algal growth and viability. It was evaluated by the use of Chlorella test, light microscopy and morphometry. Presence, absence or less intensity of green color could be traced and remarked. Chlorella test demonstrated to be useful tool for evaluating the growth/growth inhibition of different microalgal species depending on the different concentrations of the same toxicant, and has an perspective application in a comparative study of farming a new algal species. We propose this a quick, simple, indicative, non-expensive and applicative toxicity test in ecotoxicological research on the preliminary effect of toxicants also upon green algae farming.

farming algae ; Chlorella test ; morphometry ; ecotoxicology

nije evidentirano