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Overproduction of Bioactive Algal Chrysolaminarin by the Critical Carbon Flux Regulator Phosphoglucomutase
Author(s) -
Yang YuFeng,
Li DaWei,
Chen TingTing,
Hao TingBin,
Balamurugan Srinivasan,
Yang WeiDong,
Liu JieSheng,
Li HongYe
Publication year - 2019
Publication title -
biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.144
H-Index - 84
eISSN - 1860-7314
pISSN - 1860-6768
DOI - 10.1002/biot.201800220
Subject(s) - phaeodactylum tricornutum , phosphoglucomutase , biosynthesis , biochemistry , biology , vacuole , flux (metallurgy) , regulator , metabolic pathway , photosynthesis , algae , metabolism , chemistry , gene , botany , enzyme , organic chemistry , cytoplasm
Chrysolaminarin, the primary polysaccharide reservoir in some marine algae, has attracted much attention due to its broad health properties. However, its biosynthetic pathway and regulation mechanisms have rarely been reported which hinders the improvement of production efficiency. Therefore, this study aims to identify key metabolic nodes in the chrysolaminarin biosynthetic pathway. A phosphoglucomutase (PGM) in the model microalga Phaeodactylum tricornutum , revealing its critical role in chrysolaminarin biosynthesis is identified. PGM overexpression significantly elevates chrysolaminarin content by 2.54‐fold and reaches 25.6% of cell dry weight; while algal growth and photosynthesis are not impaired. Besides, PGM overexpression up‐ and down‐regulates the expression of chrysolaminarin and lipid biosynthetic genes, respectively. Microscopic analysis of aniline blue stained cells reveals that overproduced chrysolaminarin localized predominantly in vacuoles. Lipidomic analyses reveal that PGM overexpression significantly reduces the lipid content. The findings reveal the critical role of PGM in regulating the carbon flux between carbohydrate and lipid biosynthesis in microalgae, and provide a promising candidate for high efficiency production of chrysolaminarin.