Browsing by Author "De Silva, D. P. N."

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    Antimicrobial Activity of Seagrss (Cymodocea serrulata) from South West Coast of Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2013) Arulananthan, A.; De Silva, D. P. N.; Jayamanne, S. C.; Dalpatadu, S.L.; Senaratne, S. G.
    Sri Lanka has rich oceanic vegetation along its coastal water bodies. However, utilization of them is limited when compared to terrestrial plants which are used as natural alternatives especially in Ayurveda remedy. It is expected that marine vegetation also ensure the potential bioactivity. Marine plants derived natural products are known as secondary metabolites which are bioactive compounds responsible for antimicrobial activities. Documented results from most of the Atlantic, Pacific, and Indian Ocean resultant macro algae exhibits broad range of biological activities. Some of these are antibacterial, antifungal, antiviral etc. On the other hand, few literature are available on the therapeutic values of seagrasses in Sri Lanka. Therefore, the objective of this study was to test the antimicrobial activity of some selected seagrass species collected from the Beruwela beach rocky platforms and Hikkaduwa coast of Sri Lanka. Methodology Collection and preparation of samples - The fresh seagrass species (Cymodocea serrulata) was collected by hand picking during the low tidal conditions from the submerged rocky platforms of Barberrian reef and in Hikkaduwa coast. The collected vegetation was cleaned well with tap water and distilled water. Then the samples were drained and spread on the filter paper to remove excess water. Samples were chopped into nearly 1cm length pieces prior to grinding using liquid nitrogen. Solvent extraction - Coarsely powdered samples were subjected to solvent extraction by using chloroform, methanol and water solvents. The powdered form of samples and solvents were taken (1:10 w/v) and kept for 24 hours at room temperature (27 °C) in the orbital shaker at 150 rpm. Later, the extracts were filtered through a Buchner funnel with muslin cloth followed by Whatman number 1 filter paper. The resulting filtrates were concentrated by using rotary evaporator. Test microorganism - Human pathogenic Gram positive bacteria Staphylococcus aureus, Gram negative bacteria- Escherichia coli, and a fungal species Candida albicans were used to defeat the antimicrobial activity of C. serrulata. Antimicrobial susceptibility test - Antimicrobial activity of extracts was performed by using the disc diffusion method and agar well diffusion method. The stock solution was prepared with extract of 100 mg/ ml concentration of respective solvents. Sterile discs of 6 mm diameter were prepared in three different quantities (1 mg, 2 mg, and 5 mg). Each plate contained discs with three different quantities and negative control. Agar well diffusion method was carried with all extracts in same concentration as 100 mg/ ml in three different quantities (5 mg, 10 mg and 20 mg). In positive control Kanamycin 10 µl (3µg/ µl) was used for bacterial species and Flucanozole (1.25 µg/ µl) was used as antifungal agent. The plates were incubated overnight.