A LOW-COST METHODOLOGY FOR ALGAL GROWTH INHIBITION TESTS USING THREE FRESHWATER GREEN ALGAE

摘要

Freshwater microalgae are considered to be good bio-indicators and used as test organisms in several standard ecotoxicological testing procedures. The sensitivity to a toxicant may differ among the species and, thus, it is important to use a set of different species and to cross the final sensitivity of those microalgae to assess the toxicity of a compound or effluent. It is important to know the conditions guaranteeing the basic nutritive needs, allowing the performance of tests using effluents. It is also important to know the final test volume, which is proper for algal growth tests, according to the surface apparatus. An adapted methodology for three freshwater green algae (Chlorella vulgaris Beijerinck, Pseudokirchneriella subcapitata (Korshikov) Hindak, and Pandorina morum (Mueller) Bory) growth tests is proposed, establishing an easier and less expensive procedure with fewer requirements to perform algal inhibition tests. It concerns different nutritive (MBL nutrient-saturated medium and MBL dilutions) and apparatus conditions, and the most adequate biomass parameters chosen for each species.