Green algae Chlorococcum humicola-a new source of bioactive compounds with antimicrobial activity

Abstract

To analyse the existence of bioactive phytochemicals and their antimicrobial role of green algae Chlorococcum humicola (C. humicola). The various organic solvents such as acetone, benzene, chloroform, diethyl ether, ethyl acetate, ethanol, hexane and methanol were used for the preparation of the algal extracts then subjected to chemical analysis and further used for the screening of antimicrobial assay. The purified carotenoid pigments and chlorophylls were used for the antimicrobial studies against the harmful pathogens Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Klebsiella pneumoniae, Vibreo cholerae, Staphylococcus aureus, Bacillus subtilis, Candida albicans, Aspergillus niger and Aspergillus flavus. The chemical analysis showed the existence of bioactive compounds such as carotenoids, alkaloids, favanoids, fattyacids, saponins, aminoacids and carbohydrates. In vitro screening of organic solvent extracts of green algae C. humicola shows activity in inhibiting the growth of virulent strains of bacteria and fungi pathogenic to human. Eight different extracts showed effective inhibitory action against the selected pathogens. Depends upon their existence of the bioactive compounds the different organic algal extracts shows difference in their inhibitory zone against the microbes. Out of all the organic extracts benzene and ethyl acetate extracts showed excellent effect nearly 80% microbial growth inhibition. The separated carotenoid and chlorophyll fractions of C. humicola, also results in the microbial growth inhibition. The present study concludes that green algae C. humicola are a rich and varied source of pharmacologically active natural products and nutraceuticals. While nutraceutical and pharmaceutical content in the baseline algae strain is very small, they showed excellent effect against the microbial pathogens.