Growth inhibition of fouling bacteria and diatoms by extract of terrestrial plant, Derris scandens (Dicotyledonae:Leguminocae)

Abstract

Methanol extract of terrestrial plant, Derris scandens Benth, was found to inhibit growth of four diatoms and 7 bacterial species of fouling community. The concentrations required to bring about 100% inhibition of growth of the diatoms ranged between 200 to 300 mg g.ml sup(-1), whereas, the bacterial inhibition zone around the disc containing about 600-800 mu g of extract ranged between 1-5 mm. The results suggest that the crude extract of the plant is nontoxic and possesses both antibacterial and antialgal properties. Therefore, the extract promises to be a potential source of natural biocide for fouling organisms