A crosswalk on the genetic and conventional strategies for enhancing astaxanthin production in Haematococcus pluvialis

AbstractAstaxanthin is a naturally occurring xanthophyll with powerful: antioxidant, antitumor, and antibacterial properties that are widely employed in food, feed, medicinal and nutraceutical industries. Currently, chemical synthesis dominates the world’s astaxanthin market, but the increasing demand for natural products is shifting the market for natural astaxanthin. Haematococcus pluvialis (H. pluvialis) is the factory source of natural astaxanthin when grown in optimal conditions. Currently, various strategies for the production of astaxanthin have been proposed or are being developed in order to meet its market demand. This up-to-date review scrutinized the current approaches or strategies that aim to increase astaxanthin yield from H. pluvialis. We have emphasized the genetic and environmental parameters that increase astaxanthin yield. We also looked at the transcriptomic dynamics caused by environmental factors (phytohormones induction, light, salt, temperature, and nutrient starvation) on astaxanthin synthesizing genes and other metabolic changes. Genetic engineering and culture optimization (environmental factors) are effective approaches to producing more astaxanthin for commercial purposes. Genetic engineering, in particular, is accurate, specific, potent, and safer than conventional random mutagenesis approaches. New technologies, such as CRISPR-Cas9 coupled with omics and emerging computational tools, may be the principal strategies in the future to attain strains that can produce more astaxanthin. This review provides accessible data on the strategies to increase astaxanthin accumulation natively. Also, this review can be a starting point for new scholars interested in H. pluvialis research.Keywords: Haematococcus pluvialisastaxanthingenetic engineeringmutagenesistranscriptome analysisphytohormones AcknowledgmentsThe author “Adolf Acheampong” wishes to express profound gratitude to the ANSO Scholarship board for the fellowship awarded to him.Author contributionsConceptualization, A.D., and Q.H.; writing – original draft preparation, A.D., and M.S.S.; writing – review and editing, A.D., P.B-Q., M.S.S., L.L., S.M.E, Y.W., Q.H.; designed and edited the final version of the manuscript, Q.H.; supervision, Q.H. All authors have read and agreed to the published version of the manuscript.Disclosure statementThe authors have no conflicts of interest, financial or otherwise, and all authors have read and agreed to the final version of the manuscript.Additional informationFundingThis work was supported by the National Natural Science Foundation of China (grant No. 11775272) and the Research Integration Program of Hefei Institutes of Physical Science, Chinese Academy of Sciences.