Bio-prospecting of macro-algae for potential industrial dyes

Synthetic dyes have been used for different purposes in various fields, but their continued usage has presented both environmental and health challenges. Therefore, alternative safer dye sources are inevitable. Algae have different pigments with potential for exploitation and usage in different socio- economic sectors. The aim of this study was to bio prospect dyes from macro-algal species of the Indian Ocean marine ecosystem. Six algal samples were collected from Coastal beaches along the Kenyan Indian Ocean during the wet and dry seasons. The samples were processed and used for pigment extraction and screening. Pigments were extracted using ethanol, acetone, diethyl ether and hexane in sequential with distilled water. Subsequently, the crude extracts were analyzed for pigment component using spectrophotometry and qualitatively for presence of active components. From the six species, Ulva reticulata was the best dye producer in ethanol and distilled water. All extracts were coloured green except those from Galaxaura subverticillata which gave a dark red extract in 80% hexane and a brown extract in distilled water. The crude extracts also contained different active components, with phenols being the most common component in ethanol and acetone extracts. This study demonstrates that macro-algae species from the Indian Ocean ecosystem contain useful pigments for biotechnological exploitation. Future studies should focus on increasing the pigment content through genetic manipulation of macroalgae and analysis of the pigments using modern methods such as the gas chromatography-mass spectrometry (GC-MS).