Antibacterial Properties of Ten Methanolic and Ethanolic Edible Plant Leaf Extracts against Selected Pathogenic Bacteria from Aquaculture Sites

The present study is to determine the antibacterial activity of 10 methanolic and ethanolic edible plants leaves extracts against Escherichia coli, Pseudomonas aeruginosa, Aeromonas sp., and Salmonella sp. There are not many researcs available in edible plant antibacterial properties against pathogenic bacteria from aquaculture sites. Therefore this study was carried out in order to determine the effectiveness of some of the edible plant that available in Malaysia. Two different extraction solvent were used namely; 98% methanolic solution and 98% ethanolic solution to extracts the properties of the respectives plants. The antibacterial activity was determined using the well-diffusion method. Out of ten plant sample, only two methanolic extracts did not show any sign of bacterial inhibition to all bacteria tested namely; Gotu Kola (Centella asiatica L.) and Water Celery (Oenanthe javanica D.), while ethanolic plant extract recorded three negative antibacterial activity namely; Fiddlehead Fern (Diplazium esculentuni (Retz.) Sw), Gotu Kola (Centella asiatica L.) and Water Celery (Oenanthe javanica D.). Cashew (Anacardium occidentale L.) showed significant inhibition to all bacteria tested but varied in terms of inhibitory zone for both of extraction solvents. Minimum inhibitory concentration (MIC) for methanolic and ethanolic A.occidentale extracts was also conducted to determine the minimum concentration needed to inhibit growth of tested bacteria. Methanolic extracts showed lower MIC than ethanolic extract. Hence, several natural edible plants had been determined to overcome four common pathogenic bacteria from the aquaculture site had been tested. However, further research is required to justify the findings. Therefore, research must be done to apply the use of natural antibacteria in aquaculture industry in future.