|
TRITERP
Background
Natural products form the biologically relevant subset of the chemical space, having evolved through natural evolution for a variety of applications and exhibiting properties as diverse as sun protection, water binding, and pathogen resistance. They represent an invaluable source of bioactive small molecules for pharmaceutical development and, thanks to insights into their natural biological roles, enable more efficient lead identification than screening extensive combinatorial chemical libraries. These properties of functionally tested natural products are exploited by the pharmaceutical, cosmetic, and food industries, among others.
One such class of natural products is triterpenoids, which are widely distributed in plants as well as in fungi and sea cucumbers. Triterpenoids, one of the most diverse classes of natural products, have been used for centuries as active ingredients in essential oils and Chinese medicine, and are of interest in many industrial applications ranging from low-calorie sweeteners to cosmetic ingredients and vaccine adjuvants.
For example, the triterpenoid betulin is a molecule approved in Europe for wound healing and an active ingredient and emulsifier in ointments used to treat skin problems. Many other triterpenoids are being investigated for a plethora of applications, including betulinic acid and lupeol.
However, extraction from plant material can be cumbersome not only because of the low concentrations of the triterpenoid in question, but there are also increasing concerns about the sustainability of wild plant harvesting while meeting market demand.
Technology
The alternative is to produce triterpenoids with genetically modified microbes such as the yeast Saccharomyces cerevisiae based on a modified oxidosqualene cyclase. The modification reduces flux into the sterol pathway while increasing the supply of precursors for triterpenoid production.
The minimally manipulated strain was used for exemplary production of the lupan triterpenoids betulin, betulin aldehyde, and betulinic acid with a total titer greater than 6 g/L, the highest value reported to date. Squalene-, oleanane-, and dammarane-type triterpenoids can be synthesized to titers on a similar gram scale. The developed baker's yeast is a host for thousands of triterpenoid synthesis pathways from plants, reducing the pressure on natural resources. The yeast-based triterpenoid platform will improve the accessibility of these complex molecules, accelerating the exploitation of this fascinating class of natural products.
Literature
Triterpenoid production with a minimally engineered Saccharomyces cerevisiae chassis.
Hao Guo, Simo Abdessamad Baallal Jacobsen, Kerstin Walter, Anna Lewandowski, Eik Czarnotta, Christoph Knuf, Thomas Polakowski, Jérôme Maury, Christine Lang, Jochen Förster, Lars M. Blank, Birgitta E. Ebert. doi.org/10.1101/2022.07.11.499565
Non-invasive monitoring of microbial triterpenoid production using nonlinear microscopy techniques.
Dianat M, Münchberg U, Blank LM, Freier E, Ebert BE. Front Bioeng Biotechnol. 2023 Feb 28;11:1106566.
doi.org/10.3389/fbioe.2023.1106566
Recent Advances in Yeast Recombinant Biosynthesis of the Triterpenoid Protopanaxadiol and Glycosylated Derivatives Thereof.
Qiu S, Blank LM. J Agric Food Chem. 2023 Feb 8;71(5):2197-2210. doi.org/10.1021/acs.jafc.2c06888
Physiologic and metabolic characterization of Saccharomyces cerevisiae reveals limitations in the synthesis of the triterpene squalene.
Ebert BE, Czarnotta E, Blank LM. FEMS Yeast Res. 2018 Dec 1;18(8). doi.org/10.1093/femsyr/foy077
Fermentation and purification strategies for the production of betulinic acid and its lupane-type precursors in Saccharomyces cerevisiae. Czarnotta E, Dianat M, Korf M, Granica F, Merz J, Maury J, Baallal Jacobsen SA, Förster J, Ebert BE, Blank LM. Biotechnol Bioeng. 2017 Nov;114(11):2528-2538
Patent
Sequence for Protein Decay (details in Espacenet).
|
