Growth and physiological state of marine green microalgae Chlorella minutissima and Tetraselmis striata in copper polluted environment. Zh.V. MARKINA

Abstract

Growth and physiological state of marine green microalgae Chlorella minutissima and Tetraselmis striata in
copper polluted environment. Zh.V. MARKINA (A.V. Zhirmunsky National Scientific Center of Marine Biology, FEB RAS, Vladivostok, Far Eastern Federal University, Vladivostok).

Copper influence (in concentrations 50, 100 and 150 mkg/l) on population growth, chlorophyll a fluorescence, reactive oxygen species (ROS) content, mitochondrial membrane potential and neutral lipids content of marine microalgae from Chlorella minutissima and Tetraselmis striata (Chlorophyta) isolated from Peter the Great Bay (Sea of Japan) were investigated. C. minutissima growth stimulated at 50 and 100 mkg/l copper concentrations and T. striata - at 50 mkg/l. Both microalgae had decreased chlorophyll a fluorescence. C. minutissima ROS content in metal addition of 50 mkg/l were lower than control and at 100 and 150 mkg/l copper concentrations didn’t differ from microalgae growing in pure environment. T. striata ROS content increasing at copper dose 150 mkg/l. Membrane potential of C. minutissima mitochondrion were slightly altered at all copper concentrations and the parameter of T. striata significantly decreased at its addition in the amount of 100 and 150 mkg/l substance. Neutral lipids of C. minutissima increased, during microalga exposition to 50 mkg/l copper, but other concentrations didn’t alter the parameter. Toxicants in all concentrations lead to decreasing neutral lipids content in T. striata. This study revealed that T. striata more susceptible to copper that C. minutissima. Copper concentration 150 mkg/l significantly more toxic, than 50 and 100 mkg/l to both microalgae.