Publications
144 results found
Peng H, Darlington APS, South EJ, et al., 2024, A molecular toolkit of cross-feeding strains for engineering synthetic yeast communities, Nature Reviews Microbiology, Vol: 9, Pages: 848-863, ISSN: 1740-1526
Engineered microbial consortia often have enhanced system performance and robustness compared with single-strain biomanufacturing production platforms. However, few tools are available for generating co-cultures of the model and key industrial host Saccharomyces cerevisiae. Here we engineer auxotrophic and overexpression yeast strains that can be used to create co-cultures through exchange of essential metabolites. Using these strains as modules, we engineered two- and three-member consortia using different cross-feeding architectures. Through a combination of ensemble modelling and experimentation, we explored how cellular (for example, metabolite production strength) and environmental (for example, initial population ratio, population density and extracellular supplementation) factors govern population dynamics in these systems. We tested the use of the toolkit in a division of labour biomanufacturing case study and show that it enables enhanced and tuneable antioxidant resveratrol production. We expect this toolkit to become a useful resource for a variety of applications in synthetic ecology and biomanufacturing.
Darvishi F, Rafatiyan S, Abbaspour Motlagh Moghaddam MH, et al., 2024, Applications of synthetic yeast consortia for the production of native and non-native chemicals, Critical Reviews in Biotechnology, Vol: 44, Pages: 15-30, ISSN: 0738-8551
The application of microbial consortia is a new approach in synthetic biology. Synthetic yeast consortia, simple or complex synthetic mixed cultures, have been used for the production of various metabolites. Cooperation between the members of a consortium and cross-feeding can be applied to create stable microbial communication. These consortia can: consume a variety of substrates, perform more complex functions, produce metabolites in high titer, rate, and yield (TRY), and show higher stability during industrial fermentations. Due to the new research context of synthetic consortia, few yeasts were used to build these consortia, including Saccharomyces cerevisiae, Pichia pastoris, and Yarrowia lipolytica. Here, application of the yeasts for design of synthetic microbial consortia and their advantages and bottlenecks for effective and robust production of valuable metabolites from bioresource, including: cellulose, xylose, glycerol and so on, have been reviewed. Key trends and challenges are also discussed for the future development of synthetic yeast consortia.
Climent-Catala A, Casas-Rodrigo I, Iyer S, et al., 2023, Evaluating DFHBI-responsive RNA light-up aptamers as fluorescent reporters for gene expression, ACS Synthetic Biology, Vol: 12, Pages: 3754-3765, ISSN: 2161-5063
Protein-based fluorescent reporters have been widely used to characterize and localize biological processes in living cells. However, these reporters may have certain drawbacks for some applications, such as transcription-based studies or biological interactions with fast dynamics. In this context, RNA nanotechnology has emerged as a promising alternative, suggesting the use of functional RNA molecules as transcriptional fluorescent reporters. RNA-based aptamers can bind to nonfluorescent small molecules to activate their fluorescence. However, their performance as reporters of gene expression in living cells has not been fully characterized, unlike protein-based reporters. Here, we investigate the performance of three RNA light-up aptamers─F30-2xdBroccoli, tRNA-Spinach, and Tornado Broccoli─as fluorescent reporters for gene expression in Escherichia coli and compare them to a protein reporter. We examine the activation range and effect on the cell growth of RNA light-up aptamers in time-course experiments and demonstrate that these aptamers are suitable transcriptional reporters over time. Using flow cytometry, we compare the variability at the single-cell level caused by the RNA fluorescent reporters and protein-based reporters. We found that the expression of RNA light-up aptamers produced higher variability in a population than that of their protein counterpart. Finally, we compare the dynamical behavior of these RNA light-up aptamers and protein-based reporters. We observed that RNA light-up aptamers might offer faster dynamics compared to a fluorescent protein in E. coli. The implementation of these transcriptional reporters may facilitate transcription-based studies, gain further insights into transcriptional processes, and expand the implementation of RNA-based circuits in bacterial cells.
Ledesma-Amaro R, Sun M, Ledesma Amaro R, et al., 2023, High-throughput process development from gene cloning to protein production, Microbial Cell Factories, Vol: 22, ISSN: 1475-2859
In the post-genomic era, the demand for faster and more efficient protein production has increased, both in public laboratories and industry. In addition, with the expansion of protein sequences in databases, the range of possible enzymes of interest for a given application is also increasing. Faced with peer competition, budgetary, and time constraints, companies and laboratories must find ways to develop a robust manufacturing process for recombinant protein production. In this review, we explore high-throughput technologies for recombinant protein expression and present a holistic high-throughput process development strategy that spans from genes to proteins. We discuss the challenges that come with this task, the limitations of previous studies, and future research directions.
Wang J, Yu X, Wang K, et al., 2023, Reprogramming the fatty acid metabolism of Yarrowia lipolytica to produce the customized omega-6 polyunsaturated fatty acids, Bioresource Technology, Vol: 383, Pages: 1-11, ISSN: 0960-8524
Omega-6 polyunsaturated fatty acids (ω6-PUFAs), such as γ-linolenic acid (GLA), dihomo-γ-linolenic acid (DGLA) and arachidonic acid (ARA), are indispensable nutrients for human health. Harnessing the lipogenesis pathway of Yarrowia lipolytica creates a potential platform for producing customized ω6-PUFAs. This study explored the optimal biosynthetic pathways for customized production of ω6-PUFAs in Y. lipolytica via either the Δ6 pathway from Mortierella alpina or the Δ8 pathway from Isochrysis galbana. Subsequently, the proportion of ω6-PUFAs in total fatty acids (TFAs) was effectively increased by bolstering the provision of precursors for fatty acid biosynthesis and carriers for fatty acid desaturation, as well as preventing fatty acid degradation. Finally, the proportions of GLA, DGLA and ARA synthesized by customized strains accounted for 22.58%, 46.65% and 11.30% of TFAs, and the corresponding titers reached 386.59, 832.00 and 191.76 mg/L in shake-flask fermentation, respectively. This work provides valuable insights into the production of functional ω6-PUFAs.
Yuzbashev T, Yuzbashev E, Melkina O, et al., 2023, A DNA assembly toolkit to unlock the CRISPR/Cas9 potential for metabolic engineering, Communications Biology, Vol: 6, ISSN: 2399-3642
CRISPR/Cas9-based technologies are revolutionising the way we engineer microbial cells. One of the key advantages of CRISPR in strain design is that it enables chromosomal integration of marker-free DNA, eliminating laborious and often inefficient marker recovery procedures. Despite the benefits, assembling CRISPR/Cas9 editing systems is still not a straightforward process, which may prevent its use and applications. In this work, we have identified some of the main limitations of current Cas9 toolkits and designed improvements with the goal of making CRISPR technologies easier to access and implement. These include 1) A system to quickly switch between marker-free and marker-based integration constructs using both a Cre-expressing and standard Escherichia coli strains, 2) the ability to redirect multigene integration cassettes into alternative genomic loci via Golden Gate-based exchange of homology arms, 3) a rapid, simple in-vivo method to assembly guide RNA sequences via recombineering between Cas9-helper plasmids and single oligonucleotides. We combine these methodologies with well-established technologies into a comprehensive toolkit for efficient metabolic engineering using CRISPR/Cas9. As a proof of concept, we developed the YaliCraft toolkit for Yarrowia lipolytica, which is composed of a basic set of 147 plasmids and 7 modules with different purposes. We used the toolkit to generate and characterize a library of 137 promoters and to build a de novo strain synthetizing 373.8 mg/L homogentisic acid.
Peng H, Chen R, Shaw WM, et al., 2023, Modular metabolic engineering and synthetic coculture strategies for the production of aromatic compounds in yeast, ACS Synthetic Biology, Vol: 12, Pages: 1739-1749, ISSN: 2161-5063
Microbial-derived aromatics provide a sustainable and renewable alternative to petroleum-derived chemicals. In this study, we used the model yeast Saccharomyces cerevisiae to produce aromatic molecules by exploiting the concept of modularity in synthetic biology. Three different modular approaches were investigated for the production of the valuable fragrance raspberry ketone (RK), found in raspberry fruits and mostly produced from petrochemicals. The first strategy used was modular cloning, which enabled the generation of combinatorial libraries of promoters to optimize the expression level of the genes involved in the synthesis pathway of RK. The second strategy was modular pathway engineering and involved the creation of four modules, one for product formation: RK synthesis module (Mod. RK); and three for precursor synthesis: aromatic amino acid synthesis module (Mod. Aro), p-coumaric acid synthesis module (Mod. p-CA), and malonyl-CoA synthesis module (Mod. M-CoA). The production of RK by combinations of the expression of these modules was studied, and the best engineered strain produced 63.5 mg/L RK from glucose, which is the highest production described in yeast, and 2.1 mg RK/g glucose, which is the highest yield reported in any organism without p-coumaric acid supplementation. The third strategy was the use of modular cocultures to explore the effects of division of labor on RK production. Two two-member communities and one three-member community were created, and their production capacity was highly dependent on the structure of the synthetic community, the inoculation ratio, and the culture media. In certain conditions, the cocultures outperformed their monoculture controls for RK production, although this was not the norm. Interestingly, the cocultures showed up to 7.5-fold increase and 308.4 mg/L of 4-hydroxy benzalacetone, the direct precursor of RK, which can be used for the semi-synthesis of RK. This study illustrates the utility of modularity in synth
Liu P, Gong Y, Yang C, et al., 2023, Biorefining of rapeseed meal: a new and sustainable strategy for improving Cr(VI) biosorption on residual wastes from agricultural byproducts after phenolic extraction, Waste Management, Vol: 165, Pages: 70-81, ISSN: 0956-053X
Phenolic recovery from agricultural byproducts has been highlighted due to their health-promoting bioactivities. However, uncontrolled discard of residues after extraction process would induce environmental pollution and bioresource waste. In this study, biorefining of phenolic-rich rapeseed meal (RSM) and its defatted sample (dRSM) was attempted by holistic utilization of phenolic extract and residue separately. Phenolic removal could significantly improve residues' Cr(VI) adsorption capacities by about 21%, which presented extended physical surface and more released functional groups. Moreover, simulating raw material by remixing 3% separated phenolic extracts or main component sinapic acid therein with corresponding residues further improved about 12% adsorption efficiencies. These indicated that the different present forms of phenolics had opposite effects on Cr(VI) removal. While natural conjugational form inhibited hosts' biosorption, free form had enhanced functions for either extract or residue. Four optimal adsorption parameters (pH, adsorbent dosage, contact time and initial Cr(VI) concentration), three kinetic (pseudo-first order, pseudo-second order and intra-particle diffusion) models and two isotherms (Langmuir and Freundlich) were used to reveal the adsorption process. The maximum Cr(VI) adsorption capacity on residues could reach about 100 mg/g, which was superior to that of most biosorbents derived from agricultural byproducts, even some biochar. Together with the residues' advantages with everlasting capacity after 3 adsorption-desorption cycles and excellent abilities for adsorbing multiple co-existed metal ions (Cr(VI), Cd(II), Cu(II), Pb(II), Ni(II) and Zn(II)), phenolic recovery was first proved to be a new and sustainable strategy for modifying biosorbents from agricultural byproducts with zero waste.
Wang K, Lin L, Wei P, et al., 2023, Combining orthogonal plant and non-plant fatty acid biosynthesis pathways for efficient production of microbial oil enriched in nervonic acid in Yarrowia lipolytica, BIORESOURCE TECHNOLOGY, Vol: 378, ISSN: 0960-8524
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- Citations: 3
Kaur Aulakh S, Sellés Vidal L, J South E, et al., 2023, Spontaneously established syntrophic yeast communities improve bioproduction, Nature Chemical Biology, Vol: 19, Pages: 951-961, ISSN: 1552-4450
Nutritional co-dependence (syntrophy) is observed in natural microbial communities and has underexplored potential to improve biotechnological processes by using cooperating cell types. So far, design of yeast syntrophic communities has required extensive genetic manipulation, as the co-inoculation of most eukaryotic microbial auxotrophs does not result in cooperative growth. Here we employ high throughput phenotypic screening to systematically test pairwise combinations of auxotrophic S. cerevisiae deletion mutants from a genome-scale knock-out library. While most auxotrophic co-culture pairs indeed do not enter syntrophic growth, we identify 49 auxotroph pairs which defy the general rule and spontaneously form syntrophic, synergistic communities. We then characterise the stability of nine selected co-cultures and show that initial inoculation ratios of co-cultured populations significantly influence growth dynamics. We demonstrate that a pair of tryptophan auxotrophs grow by exchanging a pathway intermediate rather than the end product indicating that the metabolic space for metabolic interactions is larger than currently assumed. Exploiting this observation, we introduced a malonic semialdehyde biosynthesis pathway split between different pairs of auxotrophs, including the tryptophan auxotrophs, and obtained a 6-fold increase in relative production titer of a biotechnologically relevant compound. Our results report the spontaneous formation of stable syntrophy in a specific subset of S. cerevisiae auxotrophs and illustrate the biotechnological potential of dividing labour between a naturally cooperating intraspecies community.
Yang H, Ledesma-Amaro R, Gao H, et al., 2023, CRISPR-based biosensors for pathogenic biosafety, BIOSENSORS & BIOELECTRONICS, Vol: 228, ISSN: 0956-5663
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- Citations: 3
Graham AE, Ledesma-Amaro R, 2023, The microbial food revolution, Nature Communications, Vol: 14, ISSN: 2041-1723
Our current food system relies on unsustainable practices, which often fail to provide healthy diets to a growing population. Therefore, there is an urgent demand for new sustainable nutrition sources and processes. Microorganisms have gained attention as a new food source solution, due to their low carbon footprint, low reliance on land, water and seasonal variations coupled with a favourable nutritional profile. Furthermore, with the emergence and use of new tools, specifically in synthetic biology, the uses of microorganisms have expanded showing great potential to fulfil many of our dietary needs. In this review, we look at the different applications of microorganisms in food, and examine the history, state-of-the-art and potential to disrupt current foods systems. We cover both the use of microbes to produce whole foods out of their biomass and as cell factories to make highly functional and nutritional ingredients. The technical, economical, and societal limitations are also discussed together with the current and future perspectives.
Szczepańska P, Rychlicka M, Groborz S, et al., 2023, Studies on the anticancer and antioxidant activities of resveratrol and long-chain fatty acid esters, International Journal of Molecular Sciences, Vol: 24, ISSN: 1422-0067
Resveratrol (RES) is gaining recognition as a natural bioactive compound. To expand the possible applications of RES with its enhanced bioactivity as well as to increase the health benefits of long-chain fatty acids, a lipophilization process of RES was performed using three fatty acids: palmitic acid (PA), oleic acid (OA), and conjugated linoleic acid (CLA). The obtained mono-, di-, and tri-esters of RES were evaluated for their anticancer and antioxidant properties against lung carcinoma (A549), colorectal adenocarcinoma (HT29), and pancreatic ductal adenocarcinoma (BxPC3) cell lines. Human fibroblast (BJ) cells were used as a control. Several parameters were investigated: cell viability and apoptosis, including the expression of major pro- and anti-apoptotic markers, as well as the expression of superoxide dismutase, a key enzyme of the body's antioxidant barrier. Three of the obtained esters: mono-RES-OA, mono-RES-CLA, and tri-RES-PA, which significantly reduced the tumor cell viability up to 23%, at concentrations 25, 10, 50 μg/mL, respectively, turned out to be particularly interesting. The above-mentioned resveratrol derivatives similarly increased the tumor cells' apoptosis by modifying their caspase activity of pro-apoptotic pathways (p21, p53, and Bax). Moreover, among the mentioned esters, mono-RES-OA induced apoptosis of the analyzed cell lines most strongly, reducing the number of viable cells up to 48% for HT29 cells versus 36% for pure RES. Furthermore, the selected esters exhibited antioxidant properties towards the normal BJ cell line by regulating the expression of major pro-antioxidant genes (superoxide dismutases-SOD1 and SOD2) without the effect on their expression in the tumor, and therefore reducing the defense of cancer cells against increased oxidative stress induced by high ROS accumulation. The obtained results indicate that the esters of RES and long-chain fatty acids allow enhancement of their biological activity. The RES derivatives
Coppens L, Tschirhart T, Leary DH, et al., 2023, Vibrio natriegens genome-scale modeling reveals insights into halophilic adaptations and resource allocation, Molecular Systems Biology, Vol: 19, Pages: 1-16, ISSN: 1744-4292
Vibrio natriegens is a Gram-negative bacterium with an exceptional growth rate that has the potential to become a standard biotechnological host for laboratory and industrial bioproduction. Despite this burgeoning interest, the current lack of organism-specific qualitative and quantitative computational tools has hampered the community's ability to rationally engineer this bacterium. In this study, we present the first genome-scale metabolic model (GSMM) of V. natriegens. The GSMM (iLC858) was developed using an automated draft assembly and extensive manual curation and was validated by comparing predicted yields, central metabolic fluxes, viable carbon substrates, and essential genes with empirical data. Mass spectrometry-based proteomics data confirmed the translation of at least 76% of the enzyme-encoding genes predicted to be expressed by the model during aerobic growth in a minimal medium. iLC858 was subsequently used to carry out a metabolic comparison between the model organism Escherichia coli and V. natriegens, leading to an analysis of the model architecture of V. natriegens' respiratory and ATP-generating system and the discovery of a role for a sodium-dependent oxaloacetate decarboxylase pump. The proteomics data were further used to investigate additional halophilic adaptations of V. natriegens. Finally, iLC858 was utilized to create a Resource Balance Analysis model to study the allocation of carbon resources. Taken together, the models presented provide useful computational tools to guide metabolic engineering efforts in V. natriegens.
Wang K, Zhao W, Lin L, et al., 2023, A robust soft sensor based on artificial neural network for monitoring microbial lipid fermentation processes using <i>Yarrowia lipolytica</i>, BIOTECHNOLOGY AND BIOENGINEERING, Vol: 120, Pages: 1015-1025, ISSN: 0006-3592
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- Citations: 1
Ledesma Amaro R, Selles Vidal L, Isalan M, et al., 2023, A primer to directed evolution: current methodologies and future directions, RSC Chemical Biology, Vol: 4, Pages: 271-291, ISSN: 2633-0679
Directed evolution is one of the most powerful tools for protein engineering and functions by harnessing natural evolution, but on a shorter timescale. It enables the rapid selection of variants of biomolecules with properties that make them more suitable for specific applications. Since the first in vitro evolution experiments performed by Sol Spiegelman in 1967, a wide range of techniques have been developed to tackle the main two steps of directed evolution: genetic diversification (library generation), and isolation of the variants of interest. This review covers the main modern methodologies, discussing the advantages and drawbacks of each, and hence the considerations for designing directed evolution experiments. Furthermore, the most recent developments are discussed, showing how advances in the handling of ever larger library sizes are enabling new research questions to be tackled.
Sun T, Yu Y, Wang L, et al., 2023, Combination of a push–pull–block strategy with a heterologous xylose assimilation pathway toward lipid overproduction from lignocellulose in yarrowia lipolytica, ACS Synthetic Biology, Vol: 12, Pages: 761-767, ISSN: 2161-5063
The production of biodiesel using microbial lipids derived from renewable lignocellulosic biomass is considered a promising strategy to reduce environmental pressure and promote the green energy transition. The hydrolysates of lignocellulosic biomass are rich in glucose and xylose, which makes it crucial to efficiently utilize both sugars. Here, we combined metabolic engineering and adaptive laboratory evolution (ALE) to construct an engineered Yarrowia lipolytica strain that can efficiently produce lipids from glucose and xylose. First, the “Push–Pull–Block” strategy was adopted to increase lipid content to 73.42% of the dry cell weight (DCW). Then, a heterologous xylose-utilization pathway was integrated into the engineered strain, which was subjected to ALE. The final evolved strain could accumulate 53.64% DCW of lipids from xylose, and the lipid titer reached 16.25 g/L. This work sheds light on the potential of microbial lipid overproduction from lignocellulose using engineered Y. lipolytica.
Wu Y, Li Y, Jin K, et al., 2023, CRISPR-dCas12a-mediated genetic circuit cascades for multiplexed pathway optimization, NATURE CHEMICAL BIOLOGY, Vol: 19, Pages: 367-+, ISSN: 1552-4450
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- Citations: 4
Bi X, Cheng Y, Xu X, et al., 2023, et<i>i</i>Bsu1209: A comprehensive multiscale metabolic model for <i>Bacillus subtilis</i>, BIOTECHNOLOGY AND BIOENGINEERING, ISSN: 0006-3592
Venturelli OS, Wang HH, Estrela S, et al., 2023, What is the key challenge in engineering microbiomes?, Cell Systems, Vol: 14, Pages: 85-90, ISSN: 2405-4720
Park Y-K, Ledesma-Amaro R, 2023, What makes Yarrowia lipolytica well suited for industry?, Trends in Biotechnology, Vol: 41, Pages: 242-254, ISSN: 0167-7799
Yarrowia lipolytica possesses natural and engineered traits that make it a good host for the industrial bioproduction of chemicals, fuels, foods, and pharmaceuticals. In recent years, academic and industrial researchers have assessed its potential, developed synthetic biology techniques, improved its features, scaled its processes, and identified its limitations. Both publications and patents related to Y. lipolytica have shown a drastic increase during the past decade. Here, we discuss the characteristics of this yeast that make it suitable for industry and the remaining challenges for its wider use at large scale. We present evidence herein that shows the importance and potential of Y. lipolytica in bioproduction such that it may soon be one of the preferred choices of industry.
Cui Q, Zhong Y, Shang W, et al., 2023, Fluorescent Probe Combined with Photoelectric Analysis Technology for Detection of <i>Escherichia coli</i>, BIOSENSORS-BASEL, Vol: 13
Sun L, Zhang Q, Kong X, et al., 2023, Highly efficient neutralizer-free L-malic acid production using engineered Saccharomyces cerevisiae, BIORESOURCE TECHNOLOGY, Vol: 370, ISSN: 0960-8524
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- Citations: 5
Lin L, Ledesma-Amaro R, Ji X-J, et al., 2023, Multienzymatic synthesis of nylon monomers from vegetable oils, TRENDS IN BIOTECHNOLOGY, Vol: 41, Pages: 150-153, ISSN: 0167-7799
Hambalko J, Gajdos P, Nicaud J-M, et al., 2023, Biosynthesis of fatty acid derivatives by recombinant Yarrowia lipolytica containing MsexD2 and MsexD3 desaturase genes from Manduca sexta, Journal of Fungi, Vol: 9, Pages: 1-13, ISSN: 2309-608X
One of the most interesting groups of fatty acid derivates is the group of conjugated fatty acids from which the most researched include: conjugated linoleic acid (CLA) and conjugated linolenic acid (CLNA), which are associated with countless health benefits. Sex pheromone mixtures of some insect species, including tobacco horn-worm (Manduca sexta), are typical for the production of uncommon C16 long conjugated fatty acids with two and three conjugated double bonds, as opposed to C18 long CLA and CLNA. In this study, M. sexta desaturases MsexD2 and MsexD3 were expressed in multiple strains of Y. lipolytica with different genotypes. Experiments with the supplementation of fatty acid methyl esters into the medium resulted in the production of novel fatty acids. Using GCxGC-MS, 20 new fatty acids with two or three double bonds were identified. Fatty acids with conjugated or isolated double bonds, or a combination of both, were produced in trace amounts. The results of this study prove that Y. lipolytica is capable of synthesizing C16-conjugated fatty acids. Further genetic optimization of the Y. lipolytica genome and optimization of the fermentation process could lead to increased production of novel fatty acid derivatives with biotechnologically interesting properties.
Yu Y, Zhou Y, Wang K, et al., 2023, Metabolic and Process Engineering for Producing the Peach-Like Aroma Compound γ-Decalactone in<i> Yarrowia</i><i> lipolytica</i>, JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, Vol: 71, Pages: 110-120, ISSN: 0021-8561
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- Citations: 2
Shaw WM, Studena L, Roy K, et al., 2023, Author Correction: Inducible expression of large gRNA arrays for multiplexed CRISPRai applications( doi 10.1038/s41467-022-32603-7, 25 augu , 20220, Nature Communications, Vol: 14, Pages: 1-1, ISSN: 2041-1723
Walls LE, Otoupal P, Ledesma-Amaro R, et al., 2023, Bioconversion of cellulose into bisabolene using Ruminococcus flavefaciens and Rhodosporidium toruloides, Bioresource Technology, Vol: 368, ISSN: 0960-8524
In this study, organic acids were demonstrated as a promising carbon source for bisabolene production by the non-conventional yeast, Rhodosporidium toruloides, at microscale with a maximum titre of 1055 ± 7 mg/L. A 125-fold scale-up of the optimal process, enhanced bisabolene titres 2.5-fold to 2606 mg/L. Implementation of a pH controlled organic acid feeding strategy at this scale lead to a further threefold improvement in bisabolene titre to 7758 mg/L, the highest reported microbial titre. Finally, a proof-of-concept sequential bioreactor approach was investigated. Firstly, the cellulolytic bacterium Ruminococcus flavefaciens was employed to ferment cellulose, yielding 4.2 g/L of organic acids. R. toruloides was subsequently cultivated in the resulting supernatant, producing 318 ± 22 mg/L of bisabolene. This highlights the feasibility of a sequential bioprocess for the bioconversion of cellulose, into biojet fuel candidates. Future work will focus on enhancing organic acid yields and the use of real lignocellulosic feedstocks to further enhance bisabolene production.
Gajdos P, Ledesma-Amaro R, Nicaud J-M, et al., 2022, A yeast-based tool for screening mammalian diacylglycerol acyltransferase inhibitors, MicrobiologyOpen, Vol: 11, Pages: 1-10, ISSN: 2045-8827
Dysregulation of lipid metabolism is associated with obesity and metabolic diseases but there is also increasing evidence of a relationship between lipid body excess and cancer. Lipid body synthesis requires diacylglycerol acyltransferases (DGATs) which catalyze the last step of triacylglycerol synthesis from diacylglycerol and acyl-coenzyme A. The DGATs and in particular DGAT2, are therefore considered potential therapeutic targets for the control of these pathologies. Here, the murine and the human DGAT2 were overexpressed in the oleaginous yeast Yarrowia lipolytica deleted for all DGAT activities, to evaluate the functionality of the enzymes in this heterologous host and DGAT activity inhibitors. This work provides evidence that mammalian DGATs expressed in Y. lipolytica are a useful tool for screening chemical libraries to identify potential inhibitors or activators of these enzymes of therapeutic interest.
Cao L, Yin M, Shi T-Q, et al., 2022, Engineering Yarrowia lipolytica to produce nutritional fatty acids: Current status and future perspectives., Synthetic and Systems Biotechnology, Vol: 7, Pages: 1024-1033, ISSN: 2405-805X
Due to their vital physiological functions, nutritional fatty acids have great potential as nutraceutical food supplements for preventing an array of diseases such as inflammation, depression, arthritis, osteoporosis, diabetes and cancer. Microbial biosynthesis of fatty acids follows the trend of sustainable development, as it enables green, environmentally friendly and efficient production. As a natural oleaginous yeast, Yarrowia lipolytica is especially well-suited for the production of fatty acids. Moreover, it has a variety of genetic engineering tools and novel metabolic engineering strategies that make it a robust workhorse for the production of an array of value-added products. In this review, we summarize recent advances in metabolic engineering strategies for accumulating nutritional fatty acids in Y. lipolytica, including conjugated fatty acids and polyunsaturated fatty acids. In addition, the future prospects of nutritional fatty acid production using the Y. lipolytica platform are discussed in light of the current progress, challenges, and trends in this field. Finally, guidelines for future studies are also emphasized.
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