Antimicrobial Activity of Seagrss (Cymodocea serrulata) from South West Coast of Sri Lanka
No Thumbnail Available
Date
2013
Journal Title
Journal ISSN
Volume Title
Publisher
Uva Wellassa University of Sri Lanka
Abstract
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.
Description
Keywords
Aquaculture and Fisheries, Aquatic Resources, Aquatic Plant, Aquatic Products, Fish