Work

Modular Expression of Botryococcus braunii Genes Enhances Isoprenoid Production in the Diatom Phaeodactylum tricornutum

Year: 2026

Type: article

Abstract: Isoprenoids are essential natural compounds with high structural and functional diversity. Among them, carotenoids and triterpenoids such as squalene have high biotechnological value but remain challenging to produce sustainably. The green microalga Botryococcus braunii synthesizes large amounts of triterpenoids through specialized methylerythritol phosphate (MEP) pathway configurations involving distinct 1-deoxy-D-xylulose-5-phosphate synthase (DXS) isoforms, a bifunctional squalene synthase ( SQS ) and squalene synthase-like ( SSL ) enzymes working together for the synthesis of the compound. However, its slow growth limits industrial application. In this work, we established the fast-growing diatom Phaeodactylum tricornutum as a heterologous chassis for terpenoid production using a synthetic biology Design–Build–Test–Learn (DBTL)-based approach. Episomal uLoop assembly enabled rapid expression and evaluation of B. braunii DXS and SQS variants, enhancing precursor flux and resulting in the co-accumulation of squalene and carotenoids. This work demonstrates the functional transfer of specialized algal terpenoid enzymes into a tractable diatom host and highlight P. tricornutum ’s potential as a versatile platform for sustainable, high-value isoprenoid biosynthesis.

Source: ACS Synthetic Biology

DOI: 10.1021/acssynbio.5c00898

Authors: Luca Morelli, Cecilie Jensen, Eva C. Arnspang, Michele Fabris

Institution: University of Southern Denmark

Language: English

Topic: Plant biochemistry and biosynthesis

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funders: Villum Fonden, Novo Nordisk Fonden

Awards: G2022055534, G6669174661