Screening of some marine plants for activity against marine fouling bacteria

Sixteen marine plants collected from different locations have been tested for bactericidal activity against fifteen strains of marine fouling bacteria. Results of the primary test indicate that methanolic extracts of Sonneratia caseolaris and an unidentified moss were active against all fifteen strains of test organisms (inhibition zone ranging between 2-6 mm), while, Halodule pinifolia was totally inactive. A secondary test was used for those extracts giving a significant result in the primary test. Secondary screening showed reduction in the activity of the fractionated products as compared to aqueous methanolic extracts used in the primary test. The synergistic effect of different compounds in the aqueous methanolic extract may be responsible for the observed bactericidal activity.