Astaxanthin bioaccumulation in microalgae under environmental stress simulated in industrial effluents highlighting prospects of Haematococcus pluvialis: knowledge gaps and prospective approaches

Natural astaxanthin has shown its potential value in food, pharmaceuticals and nutraceutical industries. It is found in yeasts, algae, salmons, shrimps etc. but its substantial amounts are biosynthesized in Haematococcus pluvialis. The Haematococcus cells can biosynthesize large amounts of astaxanthin under stress conditions during their red stage to enhance the astaxanthin accumulation and elevation of its productivity. The stress related conditions are best suited in wastewater and can be an economical way of cultivating microalgae for astaxanthin production compared to the artificial media simulated growth in indoor or outdoor photobioreactors. It is well known fact that industrial effluents are rich in various macro and micronutrients which promote algal growth but, in some condition, due to absence of some nutrients the microalgal cells of Haematococcus come in conditions of stress leading to high astaxanthin accumulation. The present review discusses microalgae responsible for producing astaxanthin under stress conditions and valorising the effluents from industrial wastewater. This is further associated with optimizing techniques for culturing microalgae with high biomass and its biocompounds. It also highlights the challenges and knowledge gaps in using wastewater as medium for large scale production of valuable biocompounds like astaxanthin, which paves way towards sustainable environment. [GRAPHICS] .

Automated summary

This article discusses the production of astaxanthin in microalgae under stress conditions and the possibility of utilizing industrial wastewater. By optimizing techniques and overcoming challenges, large-scale production of valuable biocompounds such as astaxanthin can be achieved, paving the way towards sustainable environmental development.