Abstract

FRIKHA, F et al. Chemical composition and some biological activities of marine algae collected in Tunisia. Cienc. mar [online]. 2011, vol.37, n.2, pp.113-124. ISSN 0185-3880.

The chemical composition and some biological properties of four algae (Ulva rigida, Codium bursa, Cystoseira barbata, and Ceramium diaphanum) collected from the Gabes Gulf area (Tunisia) were examined. Ash (11.35-29.08% weight/dry weight [w/dw]) and total sugar (13.20-18.70% w/dw) were the most abundant contents in these algae. Protein contents were moderate (5.03-14.00% w/dw), with the red alga (C diaphanum) having the highest value. Lipid contents were within the range mentioned for seaweeds (<3% w/dw). Saturated fatty acids occurring at the highest proportions were C16:0 (24.53-41.37%) and C12:0 (10.37-24.44%). The most abundant monounsaturated fatty acid was C18:1n-9 (21.74-54.22%), whereas the most abundant polyunsaturated fatty acid was C18:2n-6 (9.57-11.71%). Variations in chemical composition can be attributed to both environmental and genetic differences among species. All algal extracts displayed antibacterial activity against Escherichia coli and Staphylococcus simulans (inhibition diameter: 10-25 mm), antioxidant activity (radical scavenging activity: 0.8-23%), and anti-inflammatory activity (48-61% inhibition of the phospholipase A2 activity); therefore, the marine algae examined can be considered abundant resources of bioactive molecules.

Keywords : marine algae; chemical composition; anti-inflammatory activity; antioxidant activity; antibacterial activity.