Untitled

Abstract

Antibacterial activity of five marine microalgae Isochrysis galbana, Chaetoceros calcitrans, Tetraselmis suecica, Nannochloropsis oculata, Aphanocapsa sp. was studied from Visakhapatnam. The ethanolic extract of T. suecica, C. calcitrans, and N. oculata s howed inhibitory activity against V. harveyi and S. Aureus with inhibition zone between 11.5 and 20mm. The ethanolic extract of I. galbana showed inhibitory activity against S. aureus only with an inhibition zone of 15mm. Among the four extracts, T. suecica showed maximum inhibitory activity against V. harveyi with an inhibition zone of 20mm. The methanolic extract of T. suecica moderately inhibited the growth of V. harveyi and S. aureus with inhibition zones of 11.5 and 11 mm respectively, whereas the extracts of I. Galbana and C. Calcitrans inhibited only V. harveyi with inhibition zones of 10 and 12 mm respectively, but no activity was found against S. aureus, A. hydrophila and E. coli. So, the studied microalgae could be used as a potential source to extract, bioactive marine natural compounds with antibacterial activity.