Critical Cultivation Parameters for Optimized Astaxanthin Biosynthesis in Haematococcus pluvialis: A Systematic Review

Abstract

Haematococcus pluvialis is a freshwater microalga renowned as one of the most potent natural producers of astaxanthin, a carotenoid with strong antioxidant properties. This microalga undergoes a distinct life cycle, transitioning between green (vegetative) and red (resting) phases, with astaxanthin accumulation occurring predominantly under stress conditions such as high light intensity, nutrient limitation, or salinity stress. Optimizing cultivation parameters is critical in enhancing astaxanthin production for various industrial applications. Despite substantial research, there remains a need to consolidate evidence on the best cultivation conditions for Haematococcus pluvialis. This review aims to identify the most effective cultivation parameters for maximizing astaxanthin production in Haematococcus pluvialis. Following the PRISMA 2020 guidelines, a systematic search was conducted across Scopus, Web of Science, and PubMed. Studies evaluating the effects of specific cultivation parameters on astaxanthin production in Haematococcus pluvialis were screened. Data extraction focused on experimental designs, cultivation methods, and astaxanthin yield. The risk of bias was assessed using the Cochrane Risk of Bias tool for laboratory-based studies. Preliminary findings suggest that factors such as high light intensity, specific nutrient limitations, and high salinity are key contributors to increased astaxanthin accumulation. Further analysis should focus on identifying optimal temperature ranges and inoculum concentrations. Conclusion: This review has identified key cultivation parameters that drive astaxanthin production in Haematococcus pluvialis. The findings may assist in refining cultivation strategies for commercial production. Future research should focus on standardizing experimental protocols to ensure better comparability across studies.