Antimicrobial activity of marine algal extracts

Total, hydrophilic and lipophilic extracts of 21 marine algae species (2 species of Chlorophyta, 11 of Phaeophyceae and 8 of Rhodophyta) collected along the coast of Russian Far East were screened for antimicrobial activities (against Staphylococcus aureus, Escherichia coli and Candida albicans). Among the macroalgal extracts analyzed, 95% were active against at least one of studied microorganisms, while 80% of extracts were active against two or more test strains. Broad-spectrum activity against three studied microorganisms was observed in the 35% of extracts from tested species of marine seaweeds. The results of our survey did not show clear taxonomic trends in the activities of the total extracts and their hydrophilic fractions against the studied microorganisms. Nevertheless, lipophilic red algal extracts had both the highest values and broadest spectrum of bioactivity among all survey algal extracts. More over, lipophilic extracts from red algal exhibited the highest activity against fungus C. albicans among tested algal extracts

Antimicrobial activity of marine algal extracts

Total, hydrophilic and lipophilic extracts of 21 marine algae species (2 species of Chlorophyta, 11 of Phaeophyceae and 8 of Rhodophyta) collected along the coast of Russian Far East were screened for antimicrobial activities (against Staphylococcus aureus, Escherichia coli and Candida albicans). Among the macroalgal extracts analyzed, 95% were active against at least one of studied microorganisms, while 80% of extracts were active against two or more test strains. Broad-spectrum activity against three studied microorganisms was observed in the 35% of extracts from tested species of marine seaweeds. The results of our survey did not show clear taxonomic trends in the activities of the total extracts and their hydrophilic fractions against the studied microorganisms. Nevertheless, lipophilic red algal extracts had both the highest values and broadest spectrum of bioactivity among all survey algal extracts. More over, lipophilic extracts from red algal exhibited the highest activity against fungus C. albicans among tested algal extracts

Seasonal variations of the composition and structural characteristics of polysaccharides from the brown alga Costaria costata

was observed in mature alga

Factors affecting yield and gelling properties of agar

Agar, a gelatinous polysaccharide in the cell wall of many red algal species, is widely used as a gelling, thickening and stabilizing agent. The commercial value of seaweed is judged by their agar content and gel quality. Seaweed materials with higher agar yield and better gelling properties are desired due to the growing demand for agar in the global market. Agar biosynthesis in seaweeds is affected by genetic variations, developmental stages and environmental conditions, while different agar extraction techniques can also affect the yield and quality of agar. In this paper, the effects of different physiological states of seaweed, abiotic and biotic factors, seaweed storage and agar extraction techniques on the agar yield and gelling characteristics, are reviewed. This information is important as a guide for marine aquaculture of potential agarophytes and the possible effects of climate change on the stock of this natural resource