The enhancement of zeaxanthin production and related genes expression in Arthrospira platensis PCC9438 under culture conditions modification

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发表日期：

2026年2月9日

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Ibrahim Ahmed Mohammed,
Kalyanee Paithoonrangsarid,
Yoshiaki Maeda,
Kohei Yoneda,
Iwane Suzuki,
Marasri Ruengjitchatchawalya

摘要

To improve zeaxanthin production and elucidate regulation of key genes in zeaxanthin biosynthesis pathway, we investigated modification of Arthrospira platensis PCC9438 culture conditions under high light (HL) and high temperature (HT). Cells were pre-cultured under HL or HT before exposure to combined stresses to stimulate production of stress-protective carotenoids, particularly zeaxanthin. The treated cell growths were comparable to the control (CT). However, carotenoid yield and content were markedly higher in the alga pre-cultured under HL and subsequently shifted to HT with either control light (HL-HTCL; 7.40 mg L⁻¹ and 6.57 mg g⁻¹) or maintained under HL (HL-HTHL; 7.86 mg L⁻¹ and 6.58 mg g⁻¹). In contrast, the alga pre-cultured under HT and then shifted to HL (HT_HLHT) revealed a significant decrease in carotenoid yield and content (2.80 mg L⁻¹ and 3.84 mg g⁻¹), compared to CT (5.53 mg L⁻¹ and 4.56 mg g⁻¹). Additionally, zeaxanthin yield and content increased significantly under HL-HTCL (1.51 mg L⁻¹ and 1.34 mg g⁻¹) and HL-HTHL (1.64 mg L⁻¹ and 1.37 mg g⁻¹) compared to CT (1.20 mg L⁻¹ and 0.99 mg g⁻¹). Transcription of key genes involved in zeaxanthin biosynthesis, phytoene synthase (crtB) and β-carotene hydroxylase (crtR), increased under HL, while that of β-carotene ketolase (crtO) decreased. Shifting to combined stresses, the expressions drastically dropped; however, transcript level of crtB and crtO were significant higher, while crtR was comparable, particularly under HL_HTHL compared to CT. This study provided an effective strategy for the induction of zeaxanthin-carotenoid biosynthesis in A. platensis through optimization of culture conditions.