Antibacterial activity of crude extracts from marine sponge Xestospongia exigua (Kirkpatrick, 1900) and its associated bacteria1

Buenaflor D. Jimenez and Jose M. Oclarit


Abstract

Crude extracts of marine sponge, Xestospongia exigua (Kirkpatrick, 1900) and its bacterial associates were prepared and assayed for antibacterial activity against selected test organisms.
Antibacterial activity was tested using Bauer-Kirby disc diffusion method using Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, as test organisms.
The sponge extract greatly inhibited E. coli and S. aureus but slightly on B. subtils and Ps. aeruginosa.
Of the 13 bacterial extracts, six have shown antibacterial activities: Alteromonas sp, Moraxella sp, Flavobacterium, Alteromonas hanadai, Corynebacterium glutamicum, The extracts of two isolates, Alteromonas sp and C. glutamicum, showed the highest antibacterial potency against the four test bacteria. The extracts of Pseudomonas sp, showed the least inhibitory effect and to only one bacterium, S. aureus.