Antimicrobial activity of seaweeds of Pernambuco, northeastern coast of Brazil

Abstract

The antibacterial efficacy of various solvent extracts of marine algae Caulerpa racemosa, Ulva lactuca (Chlorophyta), Jania adhaerens (Rhodophyta), Padina gymnospora and Sargassum polyceratium (Phaeophyta) against some selected gram-positive and gram-negative human pathogenic bacteria was screened. Crude extracts were prepared from the selected marine algae using different solvents namely, hexane, chloroform, ethyl acetate and methanol and were tested for their antibacterial activity against human pathogenic bacteria using disc diffusion method. Minimum inhibitory concentration (MIC) was also determined for selected solvent extracts for all the bacterial species. A suitable positive control was also maintained. Among the five marine algae screened C. racemosa and U. lactuca were found to be more active. It was observed that the ethyl acetate extracts of all the five marine algae showed higher inhibitory activity for the selected bacterial species than other solvent extracts. The results revealed that the crude ethyl acetate extracts seem to be a good source material in identifying the effective pure antibacterial compound(s) in all the five marine algae and particularly, C. racemosa and U. lactuca. The present study showed that the ethyl acetate extracts of marine algae such as C. racemosa, J. adhaerens, P. gymnospora, S. polyceratium and Ulva lactuca exhibited good antimicrobial activity. But the ethyl acetate extracts of C. racemosa and U. lactuca possessed highest antibacterial activity than others and so it could be useful in seeking active principles against human pathogenic bacteria.

An Overview to the Health Benefits of Seaweeds Consumption

“…However, to avoid excess of salt, sand, and heavy metal content into the soil by using the whole seaweed [175], extracts of seaweeds have been considered for production of fertilizers [16,176,177]. Many countries already utilized seaweeds extracts to produce new formulations for fertilizers in agriculture [15,178] because of their advantages which are: stimulation of seed germination, improved crop performance and yield, increased resistance to abiotic and biotic stress such as phytopathogenic fungi [179], bacteria [180], insects [181] and enhanced postharvest life and quality of the product [16,182]. Moreover, the use of seaweed is a solution to overcome hazards caused by the extensive use of chemical fertilizers.…”