Abstract

STUDIES ON ANTIMICROBIAL COMPOUNDS FROM MARINE MICROALGAE

Selvendran M.* and Saraswathi Mohan

Abstract

The antimicrobial compounds were extracted from marine microalgae such as Nanochloropsis occulata and Chaetocerous calcitrans using different organic solvents, and studied the efficiency of those extracts on aquatic pathogens such as Staphylococcus aureus, Pseudomonas aurogenosa, Vibrio harveyi, V. parahaemolyticus and Aeromonas hydrophyilla. Among the extracts obtained from microalgae, the chloroform + methanol (2:1) extract of N. occulata and butanolic extract of C. calcitrans had the maximum inhibiting activity against all aquatic pathogens. The best effected crude extracts were again purified through column chromatography and tested the inhibitory activity of eluted fractions against the same pathogens. Then the active fraction was analyzed through FTIR for knowing its functional group. The column purified extracts of antimicrobials obtained from N. occulata was found to be light sensitive compound which was activated at the light intensity of 200 lux for 18 h of light exposure. The mode of activity of the compound on the pathogenic bacteria was studied .It was observed that the active compound disturbed the cell wall formation in the pathogen. The identified active functional groups were carboxyl and nitro group in N. occulata and the nucleoside compound was the active functional group in C. calcitrans.

Keywords: Active compounds, functional group, Nanochloropsis occulata, Chaetocerus calcitrans. mode of activity.