English

Carla Corr Ecirc A Alves Renata,Renata Arruda De Souza Isabel,Paula Sant Rsquo Anna Da Silva Ana Ana,Vanusa Da Silva M Aacute Rcia,Gomes Da Silva Alexandre,Tereza Dos Santos Correia Maria,Maria Alves De Almeida Cl Eacute Bia,L Uacute Cia De Menezes Lima Vera Vera,Fernanda Figueiredo Das Merc Paula

doi:10.5897/ajmr2015.7616

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. Key words: Seaweeds, antimicrobial activity, marine macroalgae, human bacterial pathogens.

Highlights

Bacterial infection causes high rate of mortality in human population and aquaculture organisms
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 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

Summary

Introduction

Bacterial infection causes high rate of mortality in human population and aquaculture organisms. The use of antibiotics increased significantly due to heavy infections and the pathogenic bacteria becoming resistant to drugs is common due to indiscriminate use of antibiotics It becomes a greater problem of giving treatment against resistant pathogenic bacteria (Mahida and Mohan, 2007). The first to observe antimicrobial substances secreted by algae was Harder (Harder, 1917) It was not until the 1970s that large-scale screening of antimicrobial activity was carried out (Mahida and Mohan, 2007; Jones et al, 2008) and in the past few decades, macroalgae are attracting increasing attention as a new source for bioactive compounds (Arvinda Swamy, 2011)

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Conclusion