The world is becoming overwhelmed with widespread diseases as antibiotic resistance increases at an alarming rate. Hence, there is a demanding need for the discovery and development of new antimicrobial drugs. The ocean is gifted with many organisms like phytoplankton, algae, sponges, cnidarians, bryozoans, mollusk, tunicates and echinoderms, which are known to produce a wide variety of bioactive secondary metabolites with pharmacological properties. Many new therapeutic drugs have emerged from marine invertebrates, although the large algal community is yet to be explored. The bioactivity possessing secondary metabolites of marine algae include polyphenols, phlorotannins, alkaloids, halogenated compounds, sulfated polysaccharides, agar, carrageenan, proteoglycans, alginate, laminaran, rhamnan sulfate, galactosylglycerol, and fucoidan. These metabolites have been found to have great antimicrobial activities against many human aliments. Studies show that the algal community represents about 9% of biomedical compounds obtained from the sea. This review looks at the evolution of drugs from the ocean, with a special emphasis on the antimicrobial activities of marine algae.

ABSTRACT
 Antibacterial activity of marine algae
 Antifungal activity of marine algae
 Antiprotozoal activity
 Antiviral activity of marine algae
 Summary
 국문요약
 References

• Grace N.A. Charway(Inland and Aquaculture Division, Fisheries Commission, Ministry of Fisheries and Aquaculture Development, KOICA-PKNU International Graduate Program of Fisheries Science, Pukyong National University)
• Padmini Yenumula(Department of Food Science and Technology, Pukyong National University)
• Young-Mog Kim(Inland and Aquaculture Division, Fisheries Commission, Ministry of Fisheries and Aquaculture Development, Department of Food Science and Technology, Pukyong National University, Marine-Integrated Bionics Research Center, Pukyong National University) Correspondence to