Biology subjects

Jonguitud-Borrego, N.

Publications and source records attributed to Jonguitud-Borrego, N..

3 recordsLinked to original sources

bioRxiv2023

Improved Production of Taxol(R) Precursors in S. cerevisiae using Combinatorial in silico Design and Metabolic Engineering

Integrated metabolic engineering approaches combining system and synthetic biology tools allow the efficient designing of microbial cell factories to synthesize high-value products. In the present study, in silico design algorithms were used on the latest yeast genome-scale model 8.5.0 to predict potential genomic modifications that could enhance the production of early-step Taxol(R) in previously engineered Saccharomyces cerevisiae cells. The solution set containing genomic modification candidates was narrowed down by employing the COnstraints Based Reconstruction and Analysis (COBRA) methods. 17 genomic modifications consisting of nine gene deletions and eight gene overexpression were screened using wet-lab studies to determine whether these modifications can increase the production yield of taxadiene, the first metabolite in the Taxol(R) through the mevalonate pathway. Depending on the cultivation condition, most of the single genomic modifications resulted in higher taxadiene production. The best-performing strain, named KM32, contained four overexpressed genes, ILV2, TRR1, ADE13 and ECM31, from the branched-chain amino acid biosynthesis, thioredoxin system, de novo purine synthesis, and the pantothenate pathway, respectively. Using KM32, taxadiene production was increased by 50%, reaching 215 mg/L of taxadiene. The engineered strain also produced 43.65 mg/L of taxa-4(20),11-dien-5-ol (T5-ol), and 26.2 mg/L of taxa-4(20),11-dien-5--yl acetate (T5Ac) which are the highest productions of these early-step Taxol(R) metabolites reported until now in S. cerevisiae. The findings of this study highlight that the use of computational and integrated approaches can ensure determining promising modifications that are difficult to estimate intuitively to develop yeast cell factories.

synthetic biology↗

bioRxiv2023

The synergetic effect from the combination of different adsorption resins in batch and semi-continuous cultivations of S. cerevisiae cell factories to produce acetylated Taxanes precursors of the anticancer drug Taxol

In situ product recovery is an efficient way to intensify bioprocesses as it can perform adsorption of the desired natural products in the cultivation. However, it is common to use only one adsorbent (liquid or solid) to perform the product recovery. For this study, the use of an in situ product recovery method with three combined commercial resins (HP-20, XAD7HP and HP-2MG) with different chemical properties was performed. A new yeast strain of Saccharomyces cerevisiae was engineered using CRISPR Cas9 (strain EJ2) to deliver heterologous expression of oxygenated acetylated taxanes that are precursors of the anticancer drug Taxol (R) (paclitaxel). Microscale cultivations using a definitive screening design (DSD) were set to get the best resin combinations and concentrations to retrieve high taxane titers. Once the best resin treatment was selected by the DSD, semi-continuous cultivation in high throughput microscale was performed to increase the total taxanes yield up to 783 {+/-} 33 mg/L. The best T5-yl Acetate yield obtained was up to 95 {+/-} 4 mg/L, the highest titer of this compound ever reported by a heterologous expression. It was also observed that by using a combination of the resins in the cultivation, 8 additional uncharacterized taxanes were found in the gas chromatograms compared to the dodecane overlay method. Lastly, the cell-waste reactive oxygen species concentrations from the yeast were 1.5-fold lower in the resins treatment compared to the control with no adsorbent aid. The possible future implications of this method could be critical for bioprocess intensification, allowing the transition to a semi-continuous flow bioprocess. Further, this new methodology broadens the use of different organisms for natural product synthesis/discovery benefiting from clear bioprocess intensification advantages.

bioengineering↗

bioRxiv2022

ACtivE: Assembly and CRISPR-targeted in vivo Editing for Yeast Genome Engineering Using Minimum Reagents and Time

Among the numerous genetic tools developed for yeast, CRISPR/Cas system has been a widely used genome editing method thanks to its sophistication. However, CRISPR methods for yeast generally rely on pre-assembled DNAs and extra cloning steps to deliver gRNA, Cas protein, and donor DNA. These laborious steps might hinder its usefulness. Here, we propose a convenient, rapid, standardizable CRISPR method, named Assembly and CRISPR-targeted in vivo Editing (ACtivE), which only relies on in vivo assembly of linear DNA fragments for both plasmid and donor DNA construction. Thus, depending on the users need, these parts can be easily selected and combined from a repository, serving as a toolkit for rapid genome editing without any expensive reagent. The toolkit contains verified linear DNA fragments, which are easy to store, share and transport at room temperature, drastically reducing expensive shipping costs and assembly time. After optimizing this technique, eight ARS-close loci in the yeast genome were also characterized in terms of integration and gene expression efficiencies and the impacts of the disruptions of these regions on cell fitness. The flexibility and multiplexing capacity of the ACtivE were shown by constructing {beta}-carotene pathway. In only a few days, > 80% integration efficiency for single gene integration and > 50% integration efficiency for triplex integration were achieved from scratch without using in vitro DNA assembly methods, restriction enzymes, or extra cloning steps. This study presents a standardizable method to be readily employed to accelerate yeast genome engineering and provides well-defined genomic location alternatives for yeast synthetic biology and metabolic engineering purposes.

synthetic biology↗