Heavy metal stress response of microalgal strains Arthronema africanum and Coelastrella sp. BGV

By

Karcheva, Zornitsa
Georgieva, Zhaneta
Tomov, Alexander
Petrova, Detelina
Zhiponova, Miroslava
Vasileva, Ivanina
Chaneva, Ganka

Type

Article

Date of Publication

2022-4-21

Original Publication

BioRisk : biodiversity & ecosystem risk assessment

Volume

17

Pages

83--94

Subjects

Arthronema africanum , Catalase , Cd , Coelastrella sp. , Cu , Pb , pigments , superoxide dismutase

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft

Identifiers

DOI: https://doi.org/10.3897/biorisk.17.77483

 

Abstract

The present study compared the stress response of two microalgal strains – Arthronema africanum (Cyanoprokaryota) and Coelastrella sp. BGV (Chlorophyta), after heavy metals’ treatment. Changes of algal growth, pigment and protein content were analyzed after adding Cu, Cd and Pb (50 µM and 100 µM) to the nutrition medium. It was found that Cd and Pb significantly inhibited growth and protein biosynthesis of microalgae, but the effect of Cu remained less pronounced. In both strains, a decrease of chlorophyll content was observed, while carotenoid content markedly increased, especially in Coelastrella sp. BGV biomass. The addition of 100 µM Cd and 100 µM Pb to the medium caused a strong enhancement of malondialdehyde in both microalgal strains, which corresponded to the significant increase of superoxide dismutase and catalase activity. The antioxidant enzymes appeared to be differently altered by heavy metals’ exposure. The activity of SOD in the Arthronema africanum cells was most strongly affected by Cd, in contrast to Coelastrella sp. BGV that was highly increased by 100 µM Pb. The application of 100 µM Cd and 100 µM Pb increased in a similar manner catalase activity in both microalgae. The strains that were studied showed a high absorption capacity for metal ions, especially for Pb, which was absorbed largely than Cd and Cu. For that reason, we assumed that both microalga and, in particular, Coelastrella sp. BGV, could be successfully used for treatment of contaminated water bodies.