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1.
Nature ; 604(7907): 662-667, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35478237

RESUMO

Plastic waste poses an ecological challenge1-3 and enzymatic degradation offers one, potentially green and scalable, route for polyesters waste recycling4. Poly(ethylene terephthalate) (PET) accounts for 12% of global solid waste5, and a circular carbon economy for PET is theoretically attainable through rapid enzymatic depolymerization followed by repolymerization or conversion/valorization into other products6-10. Application of PET hydrolases, however, has been hampered by their lack of robustness to pH and temperature ranges, slow reaction rates and inability to directly use untreated postconsumer plastics11. Here, we use a structure-based, machine learning algorithm to engineer a robust and active PET hydrolase. Our mutant and scaffold combination (FAST-PETase: functional, active, stable and tolerant PETase) contains five mutations compared to wild-type PETase (N233K/R224Q/S121E from prediction and D186H/R280A from scaffold) and shows superior PET-hydrolytic activity relative to both wild-type and engineered alternatives12 between 30 and 50 °C and a range of pH levels. We demonstrate that untreated, postconsumer-PET from 51 different thermoformed products can all be almost completely degraded by FAST-PETase in 1 week. FAST-PETase can also depolymerize untreated, amorphous portions of a commercial water bottle and an entire thermally pretreated water bottle at 50 ºC. Finally, we demonstrate a closed-loop PET recycling process by using FAST-PETase and resynthesizing PET from the recovered monomers. Collectively, our results demonstrate a viable route for enzymatic plastic recycling at the industrial scale.


Assuntos
Hidrolases , Aprendizado de Máquina , Polietilenotereftalatos , Engenharia de Proteínas , Hidrolases/genética , Hidrolases/metabolismo , Hidrólise , Plásticos , Polietilenotereftalatos/metabolismo
2.
Small ; 20(22): e2306564, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38105580

RESUMO

3D-printed engineered living materials (ELM) are promising bioproduction platforms for agriculture, biotechnology, sustainable energy, and green technology applications. However, the design of these platforms faces several challenges, such as the processability of these materials into complex form factors and control over their mechanical properties. Herein, ELM are presented as 3D-printed bioreactors with arbitrary shape geometries and tunable mechanical properties (moduli and toughness). Poly(ethylene glycol) diacrylate (PEGDA) is used as the precursor to create polymer networks that encapsulate the microorganisms during the vat photopolymerization process. A major limitation of PEGDA networks is their propensity to swell and fracture when submerged in water. The authors overcame this issue by adding glycerol to the resin formulation to 3D print mechanically tough ELM hydrogels. While polymer concentration affects the modulus and reduces bioproduction, ELM bioreactors still maintain their metabolic activity regardless of polymer concentration. These ELM bioreactors have the potential to be used in different applications for sustainable architecture, food production, and biomedical devices that require different mechanical properties from soft to stiff.


Assuntos
Reatores Biológicos , Polietilenoglicóis , Polimerização , Impressão Tridimensional , Polietilenoglicóis/química , Hidrogéis/química , Polímeros/química
3.
Metab Eng ; 83: 1-11, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38447910

RESUMO

Flavonoids are a diverse set of natural products with promising bioactivities including anti-inflammatory, anti-cancer, and neuroprotective properties. Previously, the oleaginous host Yarrowia lipolytica has been engineered to produce high titers of the base flavonoid naringenin. Here, we leverage this host along with a set of E. coli bioconversion strains to produce the flavone apigenin and its glycosylated derivative isovitexin, two potential nutraceutical and pharmaceutical candidates. Through downstream strain selection, co-culture optimization, media composition, and mutant isolation, we were able to produce168 mg/L of apigenin, representing a 46% conversion rate of 2-(R/S)-naringenin to apigenin. This apigenin platform was modularly extended to produce isovitexin by addition of a second bioconversion strain. Together, these results demonstrate the promise of microbial production and modular bioconversion to access diversified flavonoids.


Assuntos
Apigenina , Escherichia coli , Flavanonas , Engenharia Metabólica , Yarrowia , Apigenina/metabolismo , Apigenina/biossíntese , Flavanonas/biossíntese , Flavanonas/metabolismo , Yarrowia/metabolismo , Yarrowia/genética , Escherichia coli/metabolismo , Escherichia coli/genética , Glucosídeos/biossíntese , Glucosídeos/metabolismo
4.
Nat Chem Biol ; 18(9): 981-989, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35799063

RESUMO

A key bottleneck in the microbial production of therapeutic plant metabolites is identifying enzymes that can improve yield. The facile identification of genetically encoded biosensors can overcome this limitation and become part of a general method for engineering scaled production. We have developed a combined screening and selection approach that quickly refines the affinities and specificities of generalist transcription factors; using RamR as a starting point, we evolve highly specific (>100-fold preference) and sensitive (half-maximum effective concentration (EC50) < 30 µM) biosensors for the alkaloids tetrahydropapaverine, papaverine, glaucine, rotundine and noscapine. High-resolution structures reveal multiple evolutionary avenues for the malleable effector-binding site and the creation of new pockets for different chemical moieties. These sensors further enabled the evolution of a streamlined pathway for tetrahydropapaverine, a precursor to four modern pharmaceuticals, collapsing multiple methylation steps into a single evolved enzyme. Our methods for evolving biosensors enable the rapid engineering of pathways for therapeutic alkaloids.


Assuntos
Alcaloides , Técnicas Biossensoriais , Alcaloides/química , Plantas/metabolismo
5.
Proc Natl Acad Sci U S A ; 118(36)2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34475218

RESUMO

Sorting large libraries of cells for improved small molecule secretion is throughput limited. Here, we combine producer/secretor cell libraries with whole-cell biosensors using a microfluidic-based screening workflow. This approach enables a mix-and-match capability using off-the-shelf biosensors through either coencapsulation or pico-injection. We demonstrate the cell type and library agnostic nature of this workflow by utilizing single-guide RNA, transposon, and ethyl-methyl sulfonate mutagenesis libraries across three distinct microbes (Escherichia coli, Saccharomyces cerevisiae, and Yarrowia lipolytica), biosensors from two organisms (E. coli and S. cerevisiae), and three products (triacetic acid lactone, naringenin, and L-DOPA) to identify targets improving production/secretion.


Assuntos
Ensaios de Triagem em Larga Escala/métodos , Microfluídica/métodos , Técnicas Biossensoriais , Escherichia coli/genética , Escherichia coli/metabolismo , Fluorescência , Levodopa/biossíntese , Mutagênese , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Yarrowia/genética , Yarrowia/metabolismo
6.
Adv Funct Mater ; 33(24)2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37810281

RESUMO

Engineered living materials (ELMs) combine living cells with polymeric matrices to yield unique materials with programmable functions. While the cellular platform and the polymer network determine the material properties and applications, there are still gaps in our ability to seamlessly integrate the biotic (cellular) and abiotic (polymer) components into singular material, then assemble them into devices and machines. Herein, we demonstrated the additive-manufacturing of ELMs wherein bioproduction of metabolites from the encapsulated cells enhanced the properties of the surrounding matrix. First, we developed aqueous resins comprising bovine serum albumin (BSA) and poly(ethylene glycol diacrylate) (PEGDA) with engineered microbes for vat photopolymerization to create objects with a wide array of 3D form factors. The BSA-PEGDA matrix afforded hydrogels that were mechanically stiff and tough for use in load-bearing applications. Second, we demonstrated the continuous in situ production of L-DOPA, naringenin, and betaxanthins from the engineered cells encapsulated within the BSA-PEGDA matrix. These microbial metabolites bioaugmented the properties of the BSA-PEGDA matrix by enhancing the stiffness (L-DOPA) or resistance to enzymatic degradation (betaxanthin). Finally, we demonstrated the assembly of the 3D printed ELM components into mechanically functional bolts and gears to showcase the potential to create functional ELMs for synthetic living machines.

7.
Metab Eng ; 80: 241-253, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37890611

RESUMO

Building and optimizing biosynthetic pathways in engineered cells holds promise to address societal needs in energy, materials, and medicine, but it is often time-consuming. Cell-free synthetic biology has emerged as a powerful tool to accelerate design-build-test-learn cycles for pathway engineering with increased tolerance to toxic compounds. However, most cell-free pathway prototyping to date has been performed in extracts from wildtype cells which often do not have sufficient flux towards the pathways of interest, which can be enhanced by engineering. Here, to address this gap, we create a set of engineered Escherichia coli and Saccharomyces cerevisiae strains rewired via CRISPR-dCas9 to achieve high-flux toward key metabolic precursors; namely, acetyl-CoA, shikimate, triose-phosphate, oxaloacetate, α-ketoglutarate, and glucose-6-phosphate. Cell-free extracts generated from these strains are used for targeted enzyme screening in vitro. As model systems, we assess in vivo and in vitro production of triacetic acid lactone from acetyl-CoA and muconic acid from the shikimate pathway. The need for these platforms is exemplified by the fact that muconic acid cannot be detected in wildtype extracts provided with the same biosynthetic enzymes. We also perform metabolomic comparison to understand biochemical differences between the cellular and cell-free muconic acid synthesis systems (E. coli and S. cerevisiae cells and cell extracts with and without metabolic rewiring). While any given pathway has different interfaces with metabolism, we anticipate that this set of pre-optimized, flux enhanced cell extracts will enable prototyping efforts for new biosynthetic pathways and the discovery of biochemical functions of enzymes.


Assuntos
Engenharia Metabólica , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Acetilcoenzima A/metabolismo , Extratos Celulares , Escherichia coli/metabolismo
8.
Crit Rev Biotechnol ; 43(4): 646-663, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35450502

RESUMO

The use of intracellular, biosensor-based dynamic regulation strategies to regulate and improve the production of useful compounds have progressed significantly over previous decades. By employing such an approach, it is possible to simultaneously realize high productivity and optimum growth states. However, industrial fermentation conditions contain a mixture of high- and low-performance non-genetic variants, as well as young and aged cells at all growth phases. Such significant individual variations would hinder the precise controlling of metabolic flux at the single-cell level to achieve high productivity at the macroscopic population level. Intracellular biosensors, as the regulatory centers of metabolic networks, can real-time sense intra- and extracellular conditions and, thus, could be synthetically adapted to balance the biomass formation and overproduction of compounds by individual cells. Herein, we highlight advances in the designing and engineering approaches to intracellular biosensors. Then, the spatiotemporal properties of biosensors associated with the distribution of inducers are compared. Also discussed is the use of such biosensors to dynamically control the cellular metabolic flux. Such biosensors could achieve single-cell regulation or collective regulation goals, depending on whether or not the inducer distribution is only intracellular.


Assuntos
Técnicas Biossensoriais , Engenharia Metabólica , Humanos , Idoso , Redes e Vias Metabólicas , Fermentação , Expressão Gênica
9.
Biotechnol Bioeng ; 120(2): 572-582, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36281490

RESUMO

Engineered living materials (ELMs) have broad applications for enabling on-demand bioproduction of compounds ranging from small molecules to large proteins. However, most formulations and reports lack the capacity for storage beyond a few months. In this study, we develop an optimized procedure to maximize stress resilience of yeast-laden ELMs through the use of desiccant storage and 10% trehalose incubation before lyophilization. This approach led to over 1-year room temperature storage stability across a range of strain genotypes. In particular, we highlight the superiority of exogenously added trehalose over endogenous, engineered production in yielding robust preservation resilience that is independent of cell state. This simple, effective protocol enables sufficient accumulation of intracellular trehalose over a short period of contact time across a range of strain backgrounds without requiring the overexpression of a trehalose importer. A variety of microscopic analysis including µ-CT and confocal microscopy indicate that cells form spherical colonies within F127-BUM ELMs that have variable viability upon storage. The robustness of the overall procedure developed here highlights the potential for widespread deployment to enable on-demand, cold-chain independent bioproduction.


Assuntos
Higroscópicos , Trealose , Liofilização/métodos
10.
Appl Microbiol Biotechnol ; 107(5-6): 2011-2025, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36719433

RESUMO

Hydrothermal liquefaction (HTL) is an emerging method for thermochemical conversion of wet organic waste and biomass into renewable biocrude. HTL also produces an aqueous phase (HTL-AP) side stream containing 2-4% light organic compounds that require treatment. Although anaerobic digestion (AD) of HTL-AP has shown promise, lengthy time periods were required for AD microbial communities to adapt to metabolic inhibitors in HTL-AP. An alternative for HTL-AP valorization was recently demonstrated using two engineered strains of Yarrowia lipolytica, E26 and Diploid TAL, for the overproduction of lipids and the polyketide triacetic acid lactone (TAL) respectively. These strains tolerated up to 10% HTL-AP (v/v) in defined media and up to 25% (v/v) HTL-AP in rich media. In this work, adaptive laboratory evolution (ALE) of these strains increased the bulk population tolerance for HTL-AP to up to 30% (v/v) in defined media and up to 35% (v/v) for individual isolates in rich media. The predominate organic acids within HTL-AP (acetic, butyric, and propionic) were rapidly consumed by the evolved Y. lipolytica strains. A TAL-producing isolate (strain 144-3) achieved a nearly 3-fold increase in TAL titer over the parent strain while simultaneously reducing the chemical oxygen demand (COD) of HTL-AP containing media. Fermentation with HTL-AP as the sole nutrient source demonstrated direct conversion of waste into TAL at 10% theoretical yield. Potential genetic mutations of evolved TAL production strains that could be imparting tolerance were explored. This work advances the potential of Y. lipolytica to biologically treat and simultaneously extract value from HTL wastewater. KEY POINTS: • Adaptive evolution of two Y. lipolytica strains enhanced their tolerance to waste. • Y. lipolytica reduces chemical oxygen demand in media containing waste. • Y. lipolytica can produce triacetic acid lactone directly from wastewater.


Assuntos
Policetídeos , Yarrowia , Águas Residuárias , Yarrowia/metabolismo , Fermentação , Policetídeos/metabolismo
11.
Proc Natl Acad Sci U S A ; 117(31): 18424-18430, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690674

RESUMO

Most classic genetic approaches utilize binary modifications that preclude the identification of key knockdowns for essential genes or other targets that only require moderate modulation. As a complementary approach to these classic genetic methods, we describe a plasmid-based library methodology that affords bidirectional, graded modulation of gene expression enabled by tiling the promoter regions of all 969 genes that comprise the ito977 model of Saccharomyces cerevisiae's metabolic network. When coupled with a CRISPR-dCas9-based modulation and next-generation sequencing, this method affords a library-based, bidirection titration of gene expression across all major metabolic genes. We utilized this approach in two case studies: growth enrichment on alternative sugars, glycerol and galactose, and chemical overproduction of betaxanthins, leading to the identification of unique gene targets. In particular, we identify essential genes and other targets that were missed by classic genetic approaches.


Assuntos
RNA Fúngico/genética , RNA Guia de Cinetoplastídeos/genética , Saccharomyces cerevisiae/genética , Sistemas CRISPR-Cas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Regulação Fúngica da Expressão Gênica , Biblioteca Gênica , Plasmídeos/genética , Plasmídeos/metabolismo , Regiões Promotoras Genéticas , RNA Fúngico/metabolismo , RNA Guia de Cinetoplastídeos/metabolismo , Saccharomyces cerevisiae/metabolismo
12.
Metab Eng ; 74: 24-35, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36067877

RESUMO

ß-alanine is an important biomolecule used in nutraceuticals, pharmaceuticals, and chemical synthesis. The relatively eco-friendly bioproduction of ß-alanine has recently attracted more interest than petroleum-based chemical synthesis. In this work, we developed two types of in vivo high-throughput screening platforms, wherein one was utilized to identify a novel target ribonuclease E (encoded by rne) as well as a redox-cofactor balancing module that can enhance de novo ß-alanine biosynthesis from glucose, and the other was employed for screening fermentation conditions. When combining these approaches with rational upstream and downstream module engineering, an engineered E. coli producer was developed that exhibited 3.4- and 6.6-fold improvement in ß-alanine yield (0.85 mol ß-alanine/mole glucose) and specific ß-alanine production (0.74 g/L/OD600), respectively, compared to the parental strain in a minimal medium. Across all of the strains constructed, the best yielding strain exhibited 1.08 mol ß-alanine/mole glucose (equivalent to 81.2% of theoretic yield). The final engineered strain produced 6.98 g/L ß-alanine in a batch-mode bioreactor and 34.8 g/L through a whole-cell catalysis. This approach demonstrates the utility of biosensor-enabled high-throughput screening for the production of ß-alanine.


Assuntos
Técnicas Biossensoriais , Engenharia Metabólica , Escherichia coli/genética , Escherichia coli/metabolismo , Fermentação , beta-Alanina/genética , beta-Alanina/metabolismo , Glucose/genética , Glucose/metabolismo
13.
Appl Microbiol Biotechnol ; 106(4): 1571-1581, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35099573

RESUMO

Microbial fermentation offers a sustainable source of fuels, commodity chemicals, and pharmaceuticals, yet strain performance is influenced greatly by the growth media selected. Specifically, trace metals (e.g., iron, copper, manganese, zinc, and others) are critical for proper growth and enzymatic function within microorganisms yet are non-standardized across media formulation. In this work, the effect of trace metal supplementation on the lipid production profile of Yarrowia lipolytica was explored using tube scale fermentation followed by biomass and lipid characterization. Addition of iron (II) to the chemically defined Yeast Synthetic Complete (YSC) medium increased final optical density nearly twofold and lipid production threefold, while addition of copper (II) had no impact. Additionally, dose-responsive changes in lipid distribution were observed, with the percent of oleic acid increasing and stearic acid decreasing as initial iron concentration increased. These changes were reversible with subsequent iron-selective chelation. Use of rich Yeast Peptone Dextrose (YPD) medium enabled further increases in the production of two specialty oleochemicals ultimately reaching 63 and 47% of the lipid pool as α-linolenic acid and cyclopropane fatty acid, respectively, compared to YSC medium. Selective removal of iron (II) natively present in YPD medium decreased this oleochemical production, ultimately aligning the lipid profile with that of non-supplemented YSC medium. These results provide further insight into the proposed mechanisms for iron regulation in yeasts especially as these productions strains contain a mutant allele of the iron regulator, mga2. The work presented here also suggests a non-genetic method for control of the lipid profile in Y. lipolytica for use in diverse applications. KEY POINTS: • Iron supplementation increases cell density and lipid titer in Yarrowia lipolytica. • Iron addition reversibly alters lipid portfolio increasing linolenic acid. • Removal of iron from YPD media provides a link to enhanced oleochemical production.


Assuntos
Yarrowia , Biomassa , Ácidos Graxos/química , Fermentação , Ferro , Yarrowia/genética
14.
J Ind Microbiol Biotechnol ; 49(2)2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-34529075

RESUMO

The growing burden of waste disposal coupled with natural resource scarcity has renewed interest in the remediation, valorization, and/or repurposing of waste. Traditional approaches such as composting, anaerobic digestion, use in fertilizers or animal feed, or incineration for energy production extract very little value out of these waste streams. In contrast, waste valorization into fuels and other biochemicals via microbial fermentation is an area of growing interest. In this review, we discuss microbial valorization of nonconventional, aqueous waste streams such as food processing effluents, wastewater streams, and other industrial wastes. We categorize these waste streams as carbohydrate-rich food wastes, lipid-rich wastes, and other industrial wastes. Recent advances in microbial valorization of these nonconventional waste streams are highlighted, along with a discussion of the specific challenges and opportunities associated with impurities, nitrogen content, toxicity, and low productivity.


Assuntos
Compostagem , Eliminação de Resíduos , Animais , Fertilizantes , Resíduos Industriais/análise , Águas Residuárias
15.
J Environ Manage ; 324: 116364, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36191503

RESUMO

Since 2011, a massive influx of pelagic brown algae Sargassum has invaded coastlines causing environmental and economic disaster. Valorizing this plentiful macroalgae can present much needed economic relief to the areas affected. Here the production of biodiesel and a high-value alginate stream using Sargassum biomass collected from the coast of Quintana Roo, Mexico is reported. Biomass was pretreated via AEA (Alginate Extraction Autohydrolysis) and enzymatic saccharification via fungal Solid State Fermentation, releasing 7 g/L total sugars. The sugar mixture was fermented using engineered Yarrowia lipolytica resulting in 0.35 g/L total lipid titer at the lab tube scale. Additionally, the capability of extracting 0.3875 g/g DW of a high-value, purified alginate stream from this material is demonstrated. The findings presented here are promising and suggest an opportunity for the optimization and scale up of a biodiesel production biorefinery for utilization of Sargassum seaweeds during seasons of high invasion.


Assuntos
Sargassum , Alga Marinha , Biomassa , Biocombustíveis , Açúcares , Alginatos
16.
Metab Eng ; 67: 41-52, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34052445

RESUMO

Metabolic heterogeneity and dynamic changes in metabolic fluxes are two inherent characteristics of microbial fermentation that limit the precise control of metabolisms, often leading to impaired cell growth and low productivity. Dynamic metabolic engineering addresses these challenges through the design of multi-layered and multi-genetic dynamic regulation network (DRN) that allow a single cell to autonomously adjust metabolic flux in response to its growth and metabolite accumulation conditions. Here, we developed a growth coupled NCOMB (Naringenin-Coumaric acid-Malonyl-CoA-Balanced) DRN with systematic optimization of (2S)-naringenin and p-coumaric acid-responsive regulation pathways for real-time control of intracellular supply of malonyl-CoA. In this scenario, the acyl carrier protein was used as a novel critical node for fine-tuning malonyl-CoA consumption instead of direct repression of fatty acid synthase commonly employed in previous studies. To do so, we first engineered a multi-layered DRN enabling single cells to concurrently regulate acpH, acpS, acpT, acs, and ACC in malonyl-CoA catabolic and anabolic pathways. Next, the NCOMB DRN was optimized to enhance the synergies between different dynamic regulation layers via a biosensor-based directed evolution strategy. Finally, a high producer obtained from NCOMB DRN approach yielded a 8.7-fold improvement in (2S)-naringenin production (523.7 ± 51.8 mg/L) with a concomitant 20% increase in cell growth compared to the base strain using static strain engineering approach, thus demonstrating the high efficiency of this system for improving pathway production.


Assuntos
Flavanonas , Malonil Coenzima A , Escherichia coli/genética , Engenharia Metabólica
17.
Proc Natl Acad Sci U S A ; 115(9): 2096-2101, 2018 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-29440400

RESUMO

Polyketides represent an extremely diverse class of secondary metabolites often explored for their bioactive traits. These molecules are also attractive building blocks for chemical catalysis and polymerization. However, the use of polyketides in larger scale chemistry applications is stymied by limited titers and yields from both microbial and chemical production. Here, we demonstrate that an oleaginous organism (specifically, Yarrowia lipolytica) can overcome such production limitations owing to a natural propensity for high flux through acetyl-CoA. By exploring three distinct metabolic engineering strategies for acetyl-CoA precursor formation, we demonstrate that a previously uncharacterized pyruvate bypass pathway supports increased production of the polyketide triacetic acid lactone (TAL). Ultimately, we establish a strain capable of producing over 35% of the theoretical conversion yield to TAL in an unoptimized tube culture. This strain also obtained an averaged maximum titer of 35.9 ± 3.9 g/L with an achieved maximum specific productivity of 0.21 ± 0.03 g/L/h in bioreactor fermentation. Additionally, we illustrate that a ß-oxidation-related overexpression (PEX10) can support high TAL production and is capable of achieving over 43% of the theoretical conversion yield under nitrogen starvation in a test tube. Next, through use of this bioproduct, we demonstrate the utility of polyketides like TAL to modify commodity materials such as poly(epichlorohydrin), resulting in an increased molecular weight and shift in glass transition temperature. Collectively, these findings establish an engineering strategy enabling unprecedented production from a type III polyketide synthase as well as establish a route through O-functionalization for converting polyketides into new materials.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Engenharia Genética/métodos , Pironas/metabolismo , Yarrowia/metabolismo , Estrutura Molecular , Oxirredução , Pironas/química , Piruvatos/metabolismo , Yarrowia/genética
18.
J Environ Manage ; 283: 112013, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33508553

RESUMO

Since long ago, pelagic Sargassum mats have been known to be abundant in the Sargasso Sea, where they provide habitat to diverse organisms. However, over the last few years, massive amounts of pelagic Sargassum have reached the coast of several countries in the Caribbean and West Africa, causing economic and environmental problems. Aiming for lessening the impacts of the blooms, governments and private companies remove the seaweeds from the shore, but this process results expensive. The valorization of this abundant biomass can render Sargassum tides into an economic opportunity and concurrently solve their associated environmental problems. Despite the diverse fields where algae have found applications and the relevance of this recurrent situation, Sargassum biomass remains without large scale applications. Therefore, this review aims to present the potential uses of these algae, identifying the limitations that must be assessed to effectively valorize this bioresource. Due to the constraints identified for each of the presented applications, it is concluded that a biorefinery approach should be developed to effectively valorize this abundant biomass. However, there is an urgent need for investigations focusing on holopelagic Sargassum to be able to truly valorize this seaweed.


Assuntos
Sargassum , Alga Marinha , África Ocidental , Biomassa , Região do Caribe
19.
Metab Eng ; 57: 174-181, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31740389

RESUMO

Polyketides are a diverse class of molecules sought after for their valuable properties, including as potential pharmaceuticals. Previously, we demonstrated that the oleaginous yeast Yarrowia lipolytica is an optimal host for production of the simple polyketide, triacetic acid lactone (TAL). We here expand the capacities of this host by overcoming previous media challenges and enabling production of more complex polyketides. Specifically, we employ a ß-oxidation related strategy to improve polyketide production directly from defined media. Beyond TAL production, we establish biosynthesis of the 4-coumaroyl-CoA derived polyketides: naringenin, resveratrol, and bisdemethoxycurcumin, as well as the diketide intermediate, (E)-5-(4-hydroxyphenyl)-3-oxopent-4-enoic acid. In this background, we enable high-level de novo production of naringenin through import of both a heterologous pathway and a mutant Y. lipolytica allele. In doing so, we generated an averaged maximum titer of 898 mg/L naringenin, the highest titer reported to date in any host. These results demonstrate that Y. lipolytica is an ideal polyketide production host for more complex 4-coumaroyl-CoA derived products.


Assuntos
Acil Coenzima A , Policetídeos/metabolismo , Pironas/metabolismo , Yarrowia , Acil Coenzima A/genética , Acil Coenzima A/metabolismo , Oxirredução , Yarrowia/genética , Yarrowia/metabolismo
20.
Microb Cell Fact ; 19(1): 143, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32664999

RESUMO

BACKGROUND: Resveratrol is a plant secondary metabolite with diverse, potential health-promoting benefits. Due to its nutraceutical merit, bioproduction of resveratrol via microbial engineering has gained increasing attention and provides an alternative to unsustainable chemical synthesis and straight extraction from plants. However, many studies on microbial resveratrol production were implemented with the addition of water-insoluble phenylalanine or tyrosine-based precursors to the medium, limiting in the sustainable development of bioproduction. RESULTS: Here we present a novel coculture platform where two distinct metabolic background species were modularly engineered for the combined total and de novo biosynthesis of resveratrol. In this scenario, the upstream Escherichia coli module is capable of excreting p-coumaric acid into the surrounding culture media through constitutive overexpression of codon-optimized tyrosine ammonia lyase from Trichosporon cutaneum (TAL), feedback-inhibition-resistant 3-deoxy-d-arabinoheptulosonate-7-phosphate synthase (aroGfbr) and chorismate mutase/prephenate dehydrogenase (tyrAfbr) in a transcriptional regulator tyrR knockout strain. Next, to enhance the precursor malonyl-CoA supply, an inactivation-resistant version of acetyl-CoA carboxylase (ACC1S659A,S1157A) was introduced into the downstream Saccharomyces cerevisiae module constitutively expressing codon-optimized 4-coumarate-CoA ligase from Arabidopsis thaliana (4CL) and resveratrol synthase from Vitis vinifera (STS), and thus further improve the conversion of p-coumaric acid-to-resveratrol. Upon optimization of the initial inoculation ratio of two populations, fermentation temperature, and culture time, this co-culture system yielded 28.5 mg/L resveratrol from glucose in flasks. In further optimization by increasing initial net cells density at a test tube scale, a final resveratrol titer of 36 mg/L was achieved. CONCLUSIONS: This is first study that demonstrates the use of a synthetic E. coli-S. cerevisiae consortium for de novo resveratrol biosynthesis, which highlights its potential for production of other p-coumaric-acid or resveratrol derived biochemicals.


Assuntos
Técnicas de Cocultura/métodos , Ácidos Cumáricos/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Resveratrol/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Aciltransferases/genética , Amônia-Liases/genética , Amônia-Liases/metabolismo , Arabidopsis/enzimologia , Basidiomycota/enzimologia , Corismato Mutase/genética , Corismato Mutase/metabolismo , Códon/genética , Coenzima A Ligases/genética , Coenzima A Ligases/metabolismo , Escherichia coli/crescimento & desenvolvimento , Fermentação , Genes Fúngicos , Genes de Plantas , Engenharia Genética , Microbiologia Industrial , Malonil Coenzima A/metabolismo , Engenharia Metabólica , Redes e Vias Metabólicas/genética , Prefenato Desidrogenase/genética , Prefenato Desidrogenase/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Tirosina/metabolismo , Vitis/enzimologia
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