New freshwater Microalga for Microplate Toxicity testing. Chlorella sorokiniana in comparison with the standard alga species Raphiocelis subcapitata
Translated title
NEW FRESHWATER MICROALGA FOR MICROPLATE TOXICITY TESTING. CHLORELLA SOROKINIANA IN COMPARISON WITH THE STANDARD ALGAE SPECIES RAPHIDOCELIS SUBCAPITATA
Author
Kraus, Ina
Term
4. Term
Publication year
2023
Submitted on
2023-06-01
Pages
59
Abstract
Microalgae form the base of aquatic food webs as dominant primary producers and help maintain and purify freshwater ecosystems. Discharged toxic substances can harm these microorganisms and destabilize ecosystems. Algal toxicity tests are used to classify chemicals by their hazard potential, develop water quality criteria, support biomonitoring, and assess effluents to detect hazardous substances. This study aimed to improve the standard microplate algal toxicity test by using a fast-growing freshwater microalga, Chlorella sorokiniana. C. sorokiniana had a growth rate of 2.20 d−1 and grew faster than the commonly used test species Raphidocelis subcapitata. We assessed its sensitivity to three quaternary ammonium compounds (BAC, DTAC, DDAC), four reference toxicants (K2Cr2O7, 3,5-DCP, ZnSO4, CuSO4), and two herbicide active compounds (glyphosate and pelargonic acid). Sensitivity was evaluated using EC50 values (the concentration that reduces algal growth by 50%). Across the chemicals tested, C. sorokiniana showed lower or similar EC50 values compared with the standard species, indicating equal or greater sensitivity. Its rapid growth allowed the test duration to be reduced from 72 to 48 hours. These findings support C. sorokiniana as a suitable and potentially more sensitive species for microplate algal toxicity testing.
Mikroalger udgør bunden af fødenettet og er vigtige primærproducenter, som hjælper med at opretholde og rense ferskvandsøkosystemer. Udledte giftige stoffer kan skade dem og bringe økosystemet ud af balance. Algetoksicitetstests bruges til at klassificere kemikaliers farlighed, udarbejde vandkvalitetskriterier, biomonitorere og vurdere udledninger for at opdage farlige stoffer. Dette studie sigter mod at forbedre den standard mikroplade-baserede algetoksicitetstest ved at bruge en hurtigtvoksende ferskvandsart, Chlorella sorokiniana. C. sorokiniana havde en vækstrate på 2,20 d−1 og voksede hurtigere end den ofte anvendte art Raphidocelis subcapitata. Vi undersøgte artens følsomhed over for tre kvartære ammoniumforbindelser (BAC, DTAC, DDAC), fire referencegifte (K2Cr2O7, 3,5-DCP, ZnSO4, CuSO4) og to aktivstoffer i herbicider (glyphosat og pelargonsyre). Følsomheden blev målt som EC50-værdier (den koncentration, der reducerer algevæksten med 50 %). På tværs af de testede kemikalier viste C. sorokiniana lavere eller tilsvarende EC50-værdier sammenlignet med standardarten, hvilket indikerer lige så høj eller højere følsomhed. Den hurtige vækst gjorde det muligt at forkorte testens varighed fra 72 til 48 timer. Resultaterne peger på, at C. sorokiniana er en velegnet og potentielt mere følsom art til mikroplade-baserede algetoksicitetstests.
[This apstract has been rewritten with the help of AI based on the project's original abstract]