Enhancement of β-carotene production by regulating the autophagy-carotenoid biosynthesis seesaw in Chlamydomonas reinhardtii. (November 2019)

• Record Type: Journal Article
• Authors: Tran, Quynh-Giao; Cho, Kichul; Kim, Urim; Yun, Jin-Ho; Cho, Dae-hyun; Heo, Jina; Park, Su-Bin; Kim, Ji Won; Lee, Yong Jae; Ramanan, Rishiram; Kim, Hee-Sik
• Is Part Of: Bioresource technology. Volume 292(2019)
• Publication Date: 2019-11
• Subjects: Artificial microRNA -- Autophagy -- Biodiesel properties -- Carotenoids -- Chlamydomonas reinhardtii; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2019.121937
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: The autophagy-related genes ATG1 and ATG8 were knockdown using artificial miRNA . Overproduction of β-carotene was achieved, especially in ATG8 knockdown strains. Biodiesel properties were improved due to higher SFA and MUFA contents in mutants. Abstract: This work aimed to demonstrate a new strategy for enhancing the production of carotenoids through the regulation of seesaw cross-talk between autophagy and carotenoid biosynthesis pathways in Chlamydomonas reinhardtii. Autophagy-related ATG1 and ATG8 genes were first silenced using artificial microRNA, which in turn reduced the mRNA expression of ATG1 and ATG8 by 84.4% and 74.3%, respectively. While ATG1 kinase controls early step in autophagy induction and ATG8 is an essential factor for the downstream formation of autophagosome membranes, the decreased expression of these genes led to a 2.34-fold increase in the amount of β-carotene content (i.e., 23.75 mg/g DCW). Furthermore, all mutants seemed to exhibit greater biodiesel properties than that of wild-type due to increased accumulation of saturated and monounsaturated fatty acids. These results support the role of autophagy in regulating the production of valuable metabolites, which could contribute to uplifting the economic outlook of nascent algal biorefinery.