Kappaphycus alvarezii (Doty) L. M. Liao, a red seaweed widely cultivated for carrageenan polysaccharide, is also a potential source of the valuable pigment phycoerythrin (PE). Therefore, this study aims to extract phycoerythrin from K. alvarezii, evaluate its antimicrobial, antioxidant, and anticanc...