A new Culture-Free Microbiotest for Routine Detection of Cyanobacterial Toxins
The Thamnotoxkit FTM was evaluated for detecting cyanobacterial toxins. This is a 24-hour bioassay using as test organisms larvae of the freshwater anostracan crustacean Thamnocephalus platyurus hatched from cysts. Freeze-dried Microcystis aeruginosa samples from freshwaters throughout Hungary were tested. Good correlation was obtained between the results of intraperitoneal mouse bioassays and Thamnotoxkit FTM assays. The LC50’s for purified microcystins- LR, -RR and -YR ranged from 0.1 to 2.27 µg per mL respectively in the Thamnotoxkit assay. The LC50 of laboratory cultures of Cylindrospermopsis raciborskii isolated from samples from lake Balaton, was 0.574 mg lyophilized material per mL, in a four-laboratory trial. Altough not developed originally for detecting cyanobacterial toxkins, the Thamnotoxkit FTM has good potential as an initial screening procedure for toxicity assessment of cyanobacterial scums and blooms in freshwaters.