Astaxanthin production by tropical microalgae strains isolated from environment in Malaysia

Abstract

Astaxanthin is one of the most important secondary metabolites with superior antioxidant property and is widely applied in nutraceuticals and pharmaceuticals industry. Recently, the production of astaxanthin from natural source has been mainly focused on the green microalgae, Haematococcus pluvialis, as it can accumulate large amounts of astaxanthin and its esters. However, the slow growth with low biomass yield and easy contamination by other fast-growing organisms are the main problems faced by H. pluvialis. In this study, the preliminary study on growth characteristic and amount of astaxanthin by tropical microalgae strains isolated from environment in Malaysia was reported. Two newly isolated microalgae including Acutodesmus obliquus and Coelastrum sp. were compared under various stress inductive conditions to identify the microalgae culture that can accumulate high amount of astaxanthin. The objective of this study is to compare and characterise astaxanthin accumulation using different species of green microalgae as mentioned above under different stress conditions. Findings of the preliminary studied indicated that the exposure of microalgae culture to high light intensity and nitrogen starvation in mixotrophic culture is a potential inducer of high amount of astaxanthin production. Among the two microalgae studied, Coelastrum sp., exhibited the highest tolerance to stress conditions. Outcomes of this work have shown that, astaxanthin produced in Coelastrum sp. is the most comparable to H. pluvialis and can be the potential alternative to current astaxanthin production.