Antibacterial activities of exclusive mangrove : Bruguiera gymnorrhica, B. sexangula, Ceriops decantra and Rhizophora apiculata (Rhizophoraceae) and Acrosthicum aureum (Pteridaceae)

Abstract

The important of this study is to discover a novel antibiotic for pharmaceuticals from few species of exclusive mangroves. The aims of this study are to determine the mangrove plants that having antibacterial activity, determine the minimal inhibitory concentration (MIC) of extract and to determine the plants which highest antibacterial activities. The methanolic extract of old leaves from one species of Pteridaceae; Acrosthicum aureum and four species of Rhizophoraceae; Bruguiera gymnorrhica, B. sexangula, Ceriops decantra and Rhizophora apiculata collected from Setiu Wetland and around Universiti Malaysia Terengganu were tested for antibacterial activities against seven pathogenic bacteria which are three Gram positive; Staphylococcus aureus, Micrococcus sp and Bacillus subtilis and four Gram negative; Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia and Vibrio fischeri. The disc diffusion test was used in this project. The methanolic extract of all the species in Rhizophoraceae family showed the antibacterial activity against all the Gram positive bacteria and no antibacterial activity in the Gram negative bacteria. C. decantra showed the lowest MIC value on B. subtilis at I OOµg/ml and was the only plant with the most broad spectrum activity and showed the highest antibacterial activities against all the bacteria tested. It can be concluded that the plants with the lowest MIC value could be a good source of bioactive components with antibacterial potency.