Challenges and Potential in Increasing Lutein Content in Microalgae

Abstract

Research on enhancing lutein content in microalgae has made significant progress in recent years. However, strategies are needed to address the possible limitations of microalgae as practical lutein producers. The capacity of lutein sequestration may determine the upper limit of cellular lutein content. The preliminary estimation presented in this work suggests that the lutein sequestration capacity of the light-harvesting complex (LHC) of microalgae is most likely below 2% on the basis of dry cell weight (DCW). Due to its nature as a structural pigment, higher lutein content might interfere with the LHC in fulfilling photosynthetic functions. Storing lutein in a lipophilic environment is a mechanism for achieving high lutein content but several critical barriers must be overcome such as lutein degradation and access to lipid droplet to be stored through esterification. Understanding the mechanisms underlying lipid droplet biogenesis in chloroplasts, as well as carotenoid trafficking through chloroplast membranes and carotenoid esterification, may provide insight for new approaches to achieve high lutein contents in algae. In the meantime, building the machinery for esterification and sequestration of lutein and other hydroxyl-carotenoids in model microorganisms, such as yeast, with synthetic biology technology provides a promising option.

Microalgal lutein biosynthesis: Recent trends and challenges to enhance the lutein content in microalgal cell factories

“…Elucidation of carotenoids production in bacteria, algae, protist (Patel et al, 2022) and higher plants has progressed significantly, and it is expected that primary carotenoids biosynthesis in these species follows a similar process. Figure 1 depicts the lutein synthesis route in green algae (Chlorophyta), which is subdivided into the different stages (Huang et al, 2021;Kato et al, 2021;Lou et al, 2021;Xie et al, 2021;Song et al, 2022;Velmurugan and Kodiveri Muthukaliannan, 2022). The major metabolic pathway includes the synthesis of isopentenyl diphosphate (IPP), geranylgeranyl pyrophosphate, phytoene, and desaturation of phytoene into lycopene, followed by cyclisation and hydroxylation of lycopene to lutein.…”

“…Some examples of genetically modified microalgal strains for overproduction of lutein are listed in Table 1. In a study, the lutein content in C. reinhardtii was boosted by improving the biomass Biosynthetic pathway of lutein in microalgae; source references (Huang et al, 2021;Kato et al, 2021;Lou et al, 2021;Xie et al, 2021;Song et al, 2022;Velmurugan and Kodiveri Muthukaliannan, 2022).…”

“…Harvesting costs, extraction of crude lutein, purification and bioavailability analyses have all been studied concerning microalgae to replace marigold plants in the production of lutein. Many microalgal genera, such as Scenedesmus, Chlorella, Coccomyxa, Parachlorella, and Tetraselmis, have been studied for lutein synthesis thus far (Xie et al, 2021). In this review article, we provide an overview of recent developments in the production of lutein from microalgae by employing high yield strains and genetic modification techniques to boost the lutein content.…”

Advances in Research on Natural Distribution, Biosynthesis, Detection, Bioactivity, and Application of Lutein

“…Algae are considered pigment-producing organisms, which are rich in carotenoids. 11 Most of these pigments are involved in photosynthesis in algae. Lutein protects algae cells from damage caused by bright light, which helps algae survive.…”

“…Algae are considered pigment-producing organisms, which are rich in carotenoids . Most of these pigments are involved in photosynthesis in algae.…”