Chlorella zofingiensis as an Alternative Microalgal Producer of Astaxanthin: Biology and Industrial Potential

Abstract

Astaxanthin (3,3′-dihydroxy-β,β-carotene-4,4′-dione), a high-value ketocarotenoid with a broad range of applications in food, feed, nutraceutical, and pharmaceutical industries, has been gaining great attention from science and the public in recent years. The green microalgae Haematococcus pluvialis and Chlorella zofingiensis represent the most promising producers of natural astaxanthin. Although H. pluvialis possesses the highest intracellular astaxanthin content and is now believed to be a good producer of astaxanthin, it has intrinsic shortcomings such as slow growth rate, low biomass yield, and a high light requirement. In contrast, C. zofingiensis grows fast phototrophically, heterotrophically and mixtrophically, is easy to be cultured and scaled up both indoors and outdoors, and can achieve ultrahigh cell densities. These robust biotechnological traits provide C. zofingiensis with high potential to be a better organism than H. pluvialis for mass astaxanthin production. This review aims to provide an overview of the biology and industrial potential of C. zofingiensis as an alternative astaxanthin producer. The path forward for further expansion of the astaxanthin production from C. zofingiensis with respect to both challenges and opportunities is also discussed.

Chromosome-level genome assembly and transcriptome of the green alga Chromochloris zofingiensis illuminates astaxanthin production

“…Astaxanthin has a broad range of commercial applications, including pharmaceuticals, nutraceuticals, cosmetics, food, and feed (11)(12)(13). Recent studies have highlighted the antioxidant and antiinflammatory benefits of astaxanthin for applications in human health including cancer, cardiovascular disease, neurodegenerative disease, inflammatory disease, diabetes, and obesity treatments (11,12).…”

“…Recent studies have highlighted the antioxidant and antiinflammatory benefits of astaxanthin for applications in human health including cancer, cardiovascular disease, neurodegenerative disease, inflammatory disease, diabetes, and obesity treatments (11,12). Although astaxanthin can be produced synthetically, naturally produced astaxanthin is distinct in its esterification and stereochemistry (13)(14)(15). These differences result in natural astaxanthin having >20-fold stronger antioxidant activity than synthetic astaxanthin, and only natural astaxanthin has been approved for human consumption (14).…”

“…These differences result in natural astaxanthin having >20-fold stronger antioxidant activity than synthetic astaxanthin, and only natural astaxanthin has been approved for human consumption (14). Because C. zofingiensis is fast growing, can be cultured under many conditions (including with wastewater), and reaches high culture densities, C. zofingiensis has a higher potential to meet worldwide demand than other natural sources, such as the microalga Haematococcus pluvialis, yeast, transgenic plants, and crustaceans (13,(15)(16)(17). Thus, C. zofingiensis is a prime candidate to supply the world with natural astaxanthin and a source of renewable biofuel.…”

Microalgae as a Feedstock for Biofuel Precursors and Value-Added Products: Green Fuels and Golden Opportunities

“…The remarkable accumulation of astaxanthin in Haematococcus pluvialis and Chlorella zofingiensis can often be maximized under stress culture conditions, as shown in Fig. 2 (Ip and Chen 2005;Liu et al 2014;Sun et al 2008). Some stress factors that will alter the growth and accumulation of astaxanthin in Haematococcus pluvialis and Chlorella zofingiensis are listed in Table 5.…”

Utilization of Volatile Fatty Acids from Microalgae for the Production of High Added Value Compounds

“…Other algal strains like C. protothecoides, Galdieria sulphuraria, Nitzchia laevis, C. cohnii and Neochloris oleabundans [37], have been studied due to their content in hydrogen, lipids and carotenoids, presenting a great potential to be used at large scale. C. zofingiensis has been examined as a heterotrophic alternative to the microalga H. pluvialis for production of the carotenoid astaxanthin [73]. It should be mentioned that only a few bioactive compounds apart from lipids, such as astaxanthin and β-carotene, have been produced at industrial scale, due to the low production yields in microalgae cells and the difficulties in isolating/purifying them by economically feasible processes [74,75].…”