Abstract

In vitro antibacterial screening of a marine ascidian Aplidium multiplicatum, collected from Mandapam, Southeast coast of India, against selected clinical isolates of bacteria was conducted in this study. The crude ethyl acetate extract was more active, exhibiting a broad spectrum antibacterial activity than the crude methanol extract and petroleum ether extract against each of the bacterial strains tested. Maximum inhibition zone (17 mm) was observed against the gram negative Pseudomonas aeruginosain crude ethyl acetate extract, followed by methanol extract showed activity (12.5 mm) and the petroleum ether extract of A. multiplicatum showed minimum inhibition zone (1 mm) against Klebsiella oxytoca. The range of MICs were high in ethyl acetate extract (1.80 mg/ml) and it was low in the petroleum ether (0.25 mg/ml). The range of MBCs was high in the ethyl acetate extract (2.05 mg/ml) and low concentration was observed in petroleum ether (0.55 mg/ml). Hence an attempt was made on the present study to investigate the potent antibacterials from marine ascidian.

Key words: Antibacterials, ascidians, clinical isolates, MIC, MBC.