Fermentation Strategies for Production of Pharmaceutical Terpenoids in Engineered Yeast

Abstract

Terpenoids, also known as isoprenoids, are a broad and diverse class of plant natural products with significant industrial and pharmaceutical importance. Many of these natural products have antitumor, anti-inflammatory, antibacterial, antiviral, and antimalarial effects, support transdermal absorption, prevent and treat cardiovascular diseases, and have hypoglycemic activities. Production of these compounds are generally carried out through extraction from their natural sources or chemical synthesis. However, these processes are generally unsustainable, produce low yield, and result in wasting of substantial resources, most of them limited. Microbial production of terpenoids provides a sustainable and environment-friendly alternative. In recent years, the yeast Saccharomyces cerevisiae has become a suitable cell factory for industrial terpenoid biosynthesis due to developments in omics studies (genomics, transcriptomics, metabolomics, proteomics), and mathematical modeling. Besides that, fermentation development has a significant importance on achieving high titer, yield, and productivity (TYP) of these compounds. Up to now, there have been many studies and reviews reporting metabolic strategies for terpene biosynthesis. However, fermentation strategies have not been yet comprehensively discussed in the literature. This review summarizes recent studies of recombinant production of pharmaceutically important terpenoids by engineered yeast, S. cerevisiae, with special focus on fermentation strategies to increase TYP in order to meet industrial demands to feed the pharmaceutical market. Factors affecting recombinant terpenoids production are reviewed (strain design and fermentation parameters) and types of fermentation process (batch, fed-batch, and continuous) are discussed.

Fundamental Chemistry of Essential Oils and Volatile Organic Compounds, Methods of Analysis and Authentication

“…In general, the consumer wants their essential oils to be derived from plants as in the traditional method. Some consumers will tolerate synthetic essential oils, if they are produced in a bioreactor using genetically modified yeasts [ 6 ] or plant cell cultures [ 7 ], rather than by traditional synthesis that uses potentially dangerous chemicals.…”

Efficient utilization of carbon to produce aromatic valencene in Saccharomyces cerevisiae using mannitol as the substrate

“…2,8 Actually, the metabolic characteristics of mannitol utilization by yeast, including circumvention of the rigid flux towards ethanol and high respiratory activity, are obstacles to the efficient production of ethanol from mannitol, but are superiorities in the production of natural products. 9 Terpenoids represent a large class of natural products derived from isoprene units (2-methylbuta-1,3-diene) with diverse biological activities and extensive applications in commerce and industry. 10,11 For example, valencene is an important sesquiterpenoid that imparts an odor characteristic of fresh citrus notes.…”

“…In recent years, producing valencene through microbial cell fermentation has attracted growing attention. 9 Superior terpenoid production has been achieved in microbial cell factories with efforts on metabolic engineering and fermentation process optimization in the preceding decades. 11,[13][14][15][16] Nonfermentable carbon sources, such as xylose and ethanol, have been successfully used as feedstocks to produce terpenoids and have been shown to be more effective in terpenoid production than the conventional carbon source glucose.…”

“…11,[13][14][15][16] Nonfermentable carbon sources, such as xylose and ethanol, have been successfully used as feedstocks to produce terpenoids and have been shown to be more effective in terpenoid production than the conventional carbon source glucose. 9,17 However, the extensive utilization of these nonfermentable feedstocks still suffers from challenges, including the absence of the xylose metabolic pathway in the common yeast, difficulty in releasing xylose from lignocellulosic biomass, cell stress of ethanol at high concentrations and the absolute necessity of explosion-proof equipment for the use of highly flammable ethanol. [18][19][20][21] Mannitol utilization is a fairly ubiquitous trait in organisms including some bacteria and yeast.…”

Metabolic Engineering of Saccharomyces cerevisiae for High-Level Friedelin via Genetic Manipulation

“…Sharing the common upstream biosynthetic pathway with plant triterpenes, Saccharomyces cerevisiae could provide the essential precursor 2,3-oxidosqualene, which is cyclized into diverse triterpene skeletons by oxidosqualene cyclases (OSCs) (Thimmappa et al, 2014;Rahimi et al, 2019). In S. cerevisiae, the compatibility with most membrane proteins and feasibility of genetic engineering make it a perfect chassis for the production of numerous triterpenes (Carsanba et al, 2021), such as ginsenosides Rh2 (Wang et al, 2019), α-amyrin (Yu et al, 2020), and oleanolic acid (Zhao et al, 2018).…”