From present to prosperity: assessing the current status and envisioning opportunities in the industrial-scale cultivation of Haematococcus pluvialis for astaxanthin production

Natural astaxanthin is a remarkable carotenoid with potent antioxidant activity, with a forseeable market value of $167.50 million by 2030 mainly due to its high demand as human supplement. Haematococcus pluvialis is a promising source of natural astaxanthin (3.00-7.00% by dry weight) which is being globally cultivated at an industrial scale. Nonetheless, a significant hurdle to the industrial-scale commercialization of H. pluvialis-based astaxanthin is the high market price of H. pluvialis-based astaxanthin, despite the existence of well-established production facilities. Accordingly, the present review focuses on novel strategies applicable at industrial-scale cultivation of H. pluvialis to increase biomass productivity and astaxanthin yield. Many novel strategies during green-stage including the supplementation of chemical stimulants, mixotrophic cultivation, and prevention of culture contamination are extensively studied. Similarly, incorporation of oxidative stress-inducing chemicals, culture media dilution, and pH shock are exploited in literature during red-stage cultivation of H. pluvialis. Evidently, chemical stimulants improved H. pluvialis biomass concentration to 1.10-2.37 g L-1 in the green-stage cultivation, while oxidative stress inducing-chemical stimulants enhanced the astaxanthin yield to 33.24-46.00 mg g(-1) during the red-stage cultivation. In addition, the future perspectives in the research domain are scrutinized with prominence on the techno-economic assessments of the novel strategies, development of innovative cultivation techniques, geolocation-based analysis, public perception and integration of biorefineries.