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1.
Sci Rep ; 14(1): 10894, 2024 05 13.
Article in English | MEDLINE | ID: mdl-38740817

ABSTRACT

This study evaluated the association of atherogenic index of plasma (AIP) with platelet reactivity and clinical outcomes according to acute myocardial infarction (AMI). The composite of 3-year adverse outcomes of all-cause death, myocardial infarction, and cerebrovascular accident was evaluated in 10,735 patients after successful percutaneous coronary intervention with drug-eluting stents. AIP was defined as the base 10 logarithm of the ratio of triglyceride to high-density lipoprotein cholesterol concentration. High platelet reactivity (HPR) was defined as ≥ 252 P2Y12 reactivity unit. An increase of AIP (per-0.1 unit) was related to the decreased risk of HPR [odds ratio (OR) 0.97, 95% confidence interval (CI) 0.96-0.99; P = 0.001] in non-AMI patients, not in AMI patients (OR 0.98, 95% CI 0.96-1.01; P = 0.138). The HPR was associated with the increased risk of composite outcomes in both non-AMI and AMI patients (all-P < 0.05). AIP levels were not independently associated with the risk of composite outcomes in both patients with non-AMI and AMI. In conclusion, an inverse association between AIP and the risk of HPR was observed in patients with non-AMI. This suggests that the association between plasma atherogenicity and platelet reactivity may play a substantial role in the development of AMI.Trial registration: NCT04734028.


Subject(s)
Atherosclerosis , Blood Platelets , Myocardial Infarction , Humans , Myocardial Infarction/blood , Male , Female , Middle Aged , Aged , Blood Platelets/metabolism , Atherosclerosis/blood , Percutaneous Coronary Intervention , Risk Factors , Triglycerides/blood , Cholesterol, HDL/blood , Drug-Eluting Stents , Platelet Activation
2.
Proc Natl Acad Sci U S A ; 121(19): e2403049121, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38691587

ABSTRACT

Molecular chaperones assist in protein refolding by selectively binding to proteins in their nonnative states. Despite progress in creating artificial chaperones, these designs often have a limited range of substrates they can work with. In this paper, we present molecularly imprinted flexible polymer nanoparticles (nanoMIPs) designed as customizable biomimetic chaperones. We used model proteins such as cytochrome c, laccase, and lipase to screen polymeric monomers and identify the most effective formulations, offering tunable charge and hydrophobic properties. Utilizing a dispersed phase imprinting approach, we employed magnetic beads modified with destabilized whole-protein as solid-phase templates. This process involves medium exchange facilitated by magnetic pulldowns, resulting in the synthesis of nanoMIPs featuring imprinted sites that effectively mimic chaperone cavities. These nanoMIPs were able to selectively refold denatured enzymes, achieving up to 86.7% recovery of their activity, significantly outperforming control samples. Mechanistic studies confirmed that nanoMIPs preferentially bind denatured rather than native enzymes, mimicking natural chaperone interactions. Multifaceted analyses support the functionality of nanoMIPs, which emulate the protective roles of chaperones by selectively engaging with denatured proteins to inhibit aggregation and facilitate refolding. This approach shows promise for widespread use in protein recovery within biocatalysis and biomedicine.


Subject(s)
Molecular Chaperones , Nanoparticles , Polymers , Protein Denaturation , Nanoparticles/chemistry , Molecular Chaperones/chemistry , Molecular Chaperones/metabolism , Polymers/chemistry , Protein Refolding , Protein Folding , Cytochromes c/chemistry , Cytochromes c/metabolism , Laccase/chemistry , Laccase/metabolism , Lipase/chemistry , Lipase/metabolism
3.
Microb Biotechnol ; 17(5): e14456, 2024 May.
Article in English | MEDLINE | ID: mdl-38801001

ABSTRACT

EXECUTIVE SUMMARY: Microbes are all pervasive in their distribution and influence on the functioning and well-being of humans, life in general and the planet. Microbially-based technologies contribute hugely to the supply of important goods and services we depend upon, such as the provision of food, medicines and clean water. They also offer mechanisms and strategies to mitigate and solve a wide range of problems and crises facing humanity at all levels, including those encapsulated in the sustainable development goals (SDGs) formulated by the United Nations. For example, microbial technologies can contribute in multiple ways to decarbonisation and hence confronting global warming, provide sanitation and clean water to the billions of people lacking them, improve soil fertility and hence food production and develop vaccines and other medicines to reduce and in some cases eliminate deadly infections. They are the foundation of biotechnology, an increasingly important and growing business sector and source of employment, and the centre of the bioeconomy, Green Deal, etc. But, because microbes are largely invisible, they are not familiar to most people, so opportunities they offer to effectively prevent and solve problems are often missed by decision-makers, with the negative consequences this entrains. To correct this lack of vital knowledge, the International Microbiology Literacy Initiative-the IMiLI-is recruiting from the global microbiology community and making freely available, teaching resources for a curriculum in societally relevant microbiology that can be used at all levels of learning. Its goal is the development of a society that is literate in relevant microbiology and, as a consequence, able to take full advantage of the potential of microbes and minimise the consequences of their negative activities. In addition to teaching about microbes, almost every lesson discusses the influence they have on sustainability and the SDGs and their ability to solve pressing problems of societal inequalities. The curriculum thus teaches about sustainability, societal needs and global citizenship. The lessons also reveal the impacts microbes and their activities have on our daily lives at the personal, family, community, national and global levels and their relevance for decisions at all levels. And, because effective, evidence-based decisions require not only relevant information but also critical and systems thinking, the resources also teach about these key generic aspects of deliberation. The IMiLI teaching resources are learner-centric, not academic microbiology-centric and deal with the microbiology of everyday issues. These span topics as diverse as owning and caring for a companion animal, the vast range of everyday foods that are produced via microbial processes, impressive geological formations created by microbes, childhood illnesses and how they are managed and how to reduce waste and pollution. They also leverage the exceptional excitement of exploration and discovery that typifies much progress in microbiology to capture the interest, inspire and motivate educators and learners alike. The IMiLI is establishing Regional Centres to translate the teaching resources into regional languages and adapt them to regional cultures, and to promote their use and assist educators employing them. Two of these are now operational. The Regional Centres constitute the interface between resource creators and educators-learners. As such, they will collect and analyse feedback from the end-users and transmit this to the resource creators so that teaching materials can be improved and refined, and new resources added in response to demand: educators and learners will thereby be directly involved in evolution of the teaching resources. The interactions between educators-learners and resource creators mediated by the Regional Centres will establish dynamic and synergistic relationships-a global societally relevant microbiology education ecosystem-in which creators also become learners, teaching resources are optimised and all players/stakeholders are empowered and their motivation increased. The IMiLI concept thus embraces the principle of teaching societally relevant microbiology embedded in the wider context of societal, biosphere and planetary needs, inequalities, the range of crises that confront us and the need for improved decisioning, which should ultimately lead to better citizenship and a humanity that is more sustainable and resilient. ABSTRACT: The biosphere of planet Earth is a microbial world: a vast reactor of countless microbially driven chemical transformations and energy transfers that push and pull many planetary geochemical processes, including the cycling of the elements of life, mitigate or amplify climate change (e.g., Nature Reviews Microbiology, 2019, 17, 569) and impact the well-being and activities of all organisms, including humans. Microbes are both our ancestors and creators of the planetary chemistry that allowed us to evolve (e.g., Life's engines: How microbes made earth habitable, 2023). To understand how the biosphere functions, how humans can influence its development and live more sustainably with the other organisms sharing it, we need to understand the microbes. In a recent editorial (Environmental Microbiology, 2019, 21, 1513), we advocated for improved microbiology literacy in society. Our concept of microbiology literacy is not based on knowledge of the academic subject of microbiology, with its multitude of component topics, plus the growing number of additional topics from other disciplines that become vitally important elements of current microbiology. Rather it is focused on microbial activities that impact us-individuals/communities/nations/the human world-and the biosphere and that are key to reaching informed decisions on a multitude of issues that regularly confront us, ranging from personal issues to crises of global importance. In other words, it is knowledge and understanding essential for adulthood and the transition to it, knowledge and understanding that must be acquired early in life in school. The 2019 Editorial marked the launch of the International Microbiology Literacy Initiative, the IMiLI. HERE, WE PRESENT: our concept of how microbiology literacy may be achieved and the rationale underpinning it; the type of teaching resources being created to realise the concept and the framing of microbial activities treated in these resources in the context of sustainability, societal needs and responsibilities and decision-making; and the key role of Regional Centres that will translate the teaching resources into local languages, adapt them according to local cultural needs, interface with regional educators and develop and serve as hubs of microbiology literacy education networks. The topics featuring in teaching resources are learner-centric and have been selected for their inherent relevance, interest and ability to excite and engage. Importantly, the resources coherently integrate and emphasise the overarching issues of sustainability, stewardship and critical thinking and the pervasive interdependencies of processes. More broadly, the concept emphasises how the multifarious applications of microbial activities can be leveraged to promote human/animal, plant, environmental and planetary health, improve social equity, alleviate humanitarian deficits and causes of conflicts among peoples and increase understanding between peoples (Microbial Biotechnology, 2023, 16(6), 1091-1111). Importantly, although the primary target of the freely available (CC BY-NC 4.0) IMiLI teaching resources is schoolchildren and their educators, they and the teaching philosophy are intended for all ages, abilities and cultural spectra of learners worldwide: in university education, lifelong learning, curiosity-driven, web-based knowledge acquisition and public outreach. The IMiLI teaching resources aim to promote development of a global microbiology education ecosystem that democratises microbiology knowledge.


Subject(s)
Microbiology , Microbiology/education , Humans , Biotechnology
4.
Nat Microbiol ; 9(5): 1167-1175, 2024 May.
Article in English | MEDLINE | ID: mdl-38594310

ABSTRACT

Climate change-induced alterations in weather patterns, such as frequent and severe heatwaves, cold waves, droughts, floods, heavy rain and storms, are reducing crop yields and agricultural productivity. At the same time, greenhouse gases arising from food production and supply account for almost 30% of anthropogenic emissions. This vicious circle is producing a global food crisis. Sustainable food resources and production systems are needed now, and microbial foods are one possible solution. In this Perspective, we highlight the most promising technologies, and carbon and energy sources, for microbial food production.


Subject(s)
Climate Change , Agriculture/methods , Food Supply , Food Microbiology , Carbon/metabolism , Crops, Agricultural/microbiology , Crops, Agricultural/growth & development
5.
Genome Biol ; 25(1): 66, 2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38468344

ABSTRACT

BACKGROUND: Oncometabolites, often generated as a result of a gene mutation, show pro-oncogenic function when abnormally accumulated in cancer cells. Identification of such mutation-associated metabolites will facilitate developing treatment strategies for cancers, but is challenging due to the large number of metabolites in a cell and the presence of multiple genes associated with cancer development. RESULTS: Here we report the development of a computational workflow that predicts metabolite-gene-pathway sets. Metabolite-gene-pathway sets present metabolites and metabolic pathways significantly associated with specific somatic mutations in cancers. The computational workflow uses both cancer patient-specific genome-scale metabolic models (GEMs) and mutation data to generate metabolite-gene-pathway sets. A GEM is a computational model that predicts reaction fluxes at a genome scale and can be constructed in a cell-specific manner by using omics data. The computational workflow is first validated by comparing the resulting metabolite-gene pairs with multi-omics data (i.e., mutation data, RNA-seq data, and metabolome data) from acute myeloid leukemia and renal cell carcinoma samples collected in this study. The computational workflow is further validated by evaluating the metabolite-gene-pathway sets predicted for 18 cancer types, by using RNA-seq data publicly available, in comparison with the reported studies. Therapeutic potential of the resulting metabolite-gene-pathway sets is also discussed. CONCLUSIONS: Validation of the metabolite-gene-pathway set-predicting computational workflow indicates that a decent number of metabolites and metabolic pathways appear to be significantly associated with specific somatic mutations. The computational workflow and the resulting metabolite-gene-pathway sets will help identify novel oncometabolites and also suggest cancer treatment strategies.


Subject(s)
Neoplasms , Humans , Neoplasms/genetics , Mutation , Metabolome
6.
Curr Opin Biotechnol ; 87: 103104, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38447325

ABSTRACT

Carotenoids are natural pigments that exhibit a wide range of red, orange, and yellow colors and are extensively used in the food, nutraceuticals, cosmetics, and aquaculture industries. While advances in systems metabolic engineering have established a foundation for constructing carotenoid-producing microbial cell factories at a laboratory scale, translating these technologies to industrial scales remains a big challenge. Moreover, there is a need to devise cost-effective methods for downstream processing and purification of carotenoids. In this review, we discuss recent strategies in metabolic engineering, such as metabolic flux optimization, enzyme assembly, and storage capacity engineering, aimed at constructing high-performance carotenoid-producing microbial strains. We also review recent approaches for cost-effective downstream processing and purification of carotenoids.

7.
Microb Cell Fact ; 23(1): 10, 2024 Jan 04.
Article in English | MEDLINE | ID: mdl-38178149

ABSTRACT

BACKGROUND: Crocin, a glycosylated apocarotenoid pigment predominantly found in saffron, has garnered significant interest in the field of biotechnology for its bioactive properties. Traditional production of crocins and their aglycone, crocetin, typically involves extraction from crocin-producing plants. This study aimed to develop an alternative biosynthetic method for these compounds by engineering the metabolic pathways of zeaxanthin, crocetin, and crocin in Escherichia coli strains. RESULTS: Employing a series of genetic modifications and the strategic overexpression of key enzymes, we successfully established a complete microbial pathway for synthesizing crocetin and four glycosylated derivatives of crocetin, utilizing glycerol as the primary carbon source. The overexpression of zeaxanthin cleavage dioxygenase and a novel variant of crocetin dialdehyde dehydrogenase resulted in a notable yield of crocetin (34.77 ± 1.03 mg/L). Further optimization involved the overexpression of new types of crocetin and crocin-2 glycosyltransferases, facilitating the production of crocin-1 (6.29 ± 0.19 mg/L), crocin-2 (5.29 ± 0.24 mg/L), crocin-3 (1.48 ± 0.10 mg/L), and crocin-4 (2.72 ± 0.13 mg/L). CONCLUSIONS: This investigation introduces a pioneering and integrated microbial synthesis method for generating crocin and its derivatives, employing glycerol as a sustainable carbon feedstock. The substantial yields achieved highlight the commercial potential of microbial-derived crocins as an eco-friendly alternative to plant extraction methods. The development of these microbial processes not only broadens the scope for crocin production but also suggests significant implications for the exploitation of bioengineered compounds in pharmaceutical and food industries.


Subject(s)
Escherichia coli , Glycerol , Escherichia coli/genetics , Zeaxanthins , Carbon
8.
Nat Commun ; 15(1): 908, 2024 Jan 30.
Article in English | MEDLINE | ID: mdl-38291035

ABSTRACT

Ice crystals at low temperatures exhibit structural polymorphs including hexagonal ice, cubic ice, or a hetero-crystalline mixture of the two phases. Despite the significant implications of structure-dependent roles of ice, mechanisms behind the growths of each polymorph have been difficult to access quantitatively. Using in-situ cryo-electron microscopy and computational ice-dynamics simulations, we directly observe crystalline ice growth in an amorphous ice film of nanoscale thickness, which exhibits three-dimensional ice nucleation and subsequent two-dimensional ice growth. We reveal that nanoscale ice crystals exhibit polymorph-dependent growth kinetics, while hetero-crystalline ice exhibits anisotropic growth, with accelerated growth occurring at the prismatic planes. Fast-growing facets are associated with low-density interfaces that possess higher surface energy, driving tetrahedral ordering of interfacial H2O molecules and accelerating ice growth. These findings, based on nanoscale observations, improve our understanding on early stages of ice formation and mechanistic roles of the ice interface.

9.
ChemSusChem ; 17(7): e202301044, 2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38030584

ABSTRACT

A crystalline supramolecular photocatalyst is prepared through metal-induced self-assembly of perylene diimide with imidazole groups at the imide position (PDI-Hm). Exploiting the metal-coordination ability of imidazole, a crystalline assembly of copper-coordinated PDI-Hm (CuPDI-Hm) in a nanorod shape is prepared which displays an outstanding photocatalytic oxygen evolution rate of 25,900 µmol g-1 h-1 without additional co-catalysts. The imidazole-copper coordination, along with π-π stacking of PDI frameworks, guides the arrangement of PDI-Hm molecules to form highly crystalline assemblies. The coordination of copper also modulates the size of the CuPDI-Hm supramolecular assembly by regulating the nucleation and growth processes. Furthermore, the imidazole-copper coordination constructs the electric field within the PDI-Hm assembly, hindering the recombination of photo-induced charges to enhance the photoelectric/photocatalytic activity when compared to Cu-free PDI-Hm assemblies. Small CuPDI-Hm assembly exhibits higher photocatalytic activity due to their larger surface area and reduced light scattering. Together, the Cu-imidazole coordination presents a facile way for fabricating size-controlled crystalline PDI assemblies with built-in electric field enhancing photoelectric and photocatalytic activities substantially.

10.
Nat Commun ; 14(1): 7370, 2023 11 14.
Article in English | MEDLINE | ID: mdl-37963869

ABSTRACT

Functional annotation of open reading frames in microbial genomes remains substantially incomplete. Enzymes constitute the most prevalent functional gene class in microbial genomes and can be described by their specific catalytic functions using the Enzyme Commission (EC) number. Consequently, the ability to predict EC numbers could substantially reduce the number of un-annotated genes. Here we present a deep learning model, DeepECtransformer, which utilizes transformer layers as a neural network architecture to predict EC numbers. Using the extensively studied Escherichia coli K-12 MG1655 genome, DeepECtransformer predicted EC numbers for 464 un-annotated genes. We experimentally validated the enzymatic activities predicted for three proteins (YgfF, YciO, and YjdM). Further examination of the neural network's reasoning process revealed that the trained neural network relies on functional motifs of enzymes to predict EC numbers. Thus, DeepECtransformer is a method that facilitates the functional annotation of uncharacterized genes.


Subject(s)
Deep Learning , Escherichia coli K12 , Escherichia coli K12/genetics , Proteins/genetics , Genome , Escherichia coli/genetics , Molecular Sequence Annotation , Open Reading Frames
11.
Cell Syst ; 14(11): 990-1001.e5, 2023 11 15.
Article in English | MEDLINE | ID: mdl-37935194

ABSTRACT

In metabolic engineering, predicting gene overexpression targets remains challenging because both endogenous and heterologous genes in a large metabolic space can be candidates, in contrast to gene knockout targets that are confined to endogenous genes. We report the development of iBridge that identifies positive and negative metabolites exerting positive and negative impacts on product formation, respectively, based on the sum of covariances of their outgoing (consuming) reaction fluxes for a target chemical. Then, "bridge" reactions converting negative metabolites to positive metabolites are identified as overexpression targets, while the opposites as downregulation targets. Using iBridge, overexpression and downregulation targets are suggested for the production of 298 chemicals and validated for 36 chemicals experimentally demonstrated in previous studies. Finally, iBridge is employed to engineer Escherichia coli strains capable of producing 10.3 g/L of D-panthenol, a compound not previously produced, as well as putrescine and 4-hydroxyphenyllactate at enhanced titers, 63.7 and 8.3 g/L, respectively.


Subject(s)
Escherichia coli , Metabolic Engineering , Down-Regulation/genetics , Escherichia coli/genetics , Escherichia coli/metabolism , Genome
12.
Nat Microbiol ; 8(12): 2253-2276, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38030909

ABSTRACT

Plastics are indispensable in everyday life and industry, but the environmental impact of plastic waste on ecosystems and human health is a huge concern. Microbial biotechnology offers sustainable routes to plastic production and waste management. Bacteria and fungi can produce plastics, as well as their constituent monomers, from renewable biomass, such as crops, agricultural residues, wood and organic waste. Bacteria and fungi can also degrade plastics. We review state-of-the-art microbial technologies for sustainable production and degradation of bio-based plastics and highlight the potential contributions of microorganisms to a circular economy for plastics.


Subject(s)
Ecosystem , Plastics , Humans , Plastics/chemistry , Plastics/metabolism , Biotechnology , Bacteria/genetics , Bacteria/metabolism
13.
Curr Opin Biotechnol ; 84: 103004, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37778304

ABSTRACT

Systems metabolic engineering, which integrates metabolic engineering with systems biology, synthetic biology, and evolutionary engineering, has revolutionized the sustainable production of fuels and materials through the creation of efficient microbial cell factories. Recent advancements in systems metabolic engineering targeting different biological components of the host cell have enabled the creation of highly productive microbial cell factories. This article provides a review of the recent tools and strategies used for enzyme-, genetic module-, pathway-, flux-, genome-, and cell-level engineering, supported by illustrative examples. Furthermore, we highlight recent trends in systems metabolic engineering, which involve the application of multiple tools discussed in this review. Finally, the paper addresses the challenges and perspectives of transitioning academic-level metabolic engineering studies to commercial-scale production.


Subject(s)
Metabolic Engineering , Metabolic Networks and Pathways , Systems Biology , Synthetic Biology , Genome
14.
Front Psychiatry ; 14: 1260567, 2023.
Article in English | MEDLINE | ID: mdl-37840788

ABSTRACT

We examined whether media coverage of suicides and frequencies of searching for suicide methods or suicide pacts predicted the number of users posting tweets seeking others for a suicide pact. Analyses of 6,119 tweets containing "suicide pact" posted on Twitter during a 6-month period revealed that the number of users posting tweets seeking others for a suicide pact had a positive association with media coverage of celebrity suicides, but not with that of suicide pact victims, and a greater positive association with the search frequency for suicide methods than for suicide pacts. We found that the search frequency on suicide methods was positively associated with media coverage of celebrity suicides, while that on suicide pacts was more strongly related to media coverage of suicide pacts.

15.
Dalton Trans ; 52(37): 13269-13277, 2023 Sep 26.
Article in English | MEDLINE | ID: mdl-37668062

ABSTRACT

In this study, we present a colloidal assembly of histidyl bolaamphiphiles whose imidazoles coordinate with rhodium ions (HisC7[Rh]) to exhibit catalytic isomerization activity for cis-stilbene and cis-alkene molecules. The histidyl bolaamphiphiles self-assemble to form a soft scaffold that functions analogously to an apoenzyme. This scaffold exposes multiple histidyl imidazoles and carboxylates on its surface, to which rhodium ions bind, generating catalytically active sites. The Rh coordination with the biochemical functional groups was verified through comprehensive vibrational spectroscopy and calorimetry. The colloidal HisC7[Rh] demonstrated a significant catalytic effect on the isomerization of cis- to trans-stilbene under mild H2 conditions, resulting in 69% yield of trans-stilbene. In contrast, when Rh(cod)2BF4 was employed as a control catalyst, only the hydrogenated products of bibenzyl were obtained. These findings underscore the crucial role of histidyl motifs in exhibiting unique catalytic isomerization activity through the coordination with Rh. The catalytic activity of HisC7[Rh] is governed by several factors, such as rhodium content, solvent composition, temperature, and H2 pressure. Moreover, HisC7[Rh] displayed moderate isomerization activity towards not only stilbene but also unsaturated fatty acid isomers, highlighting its expansive potential as an isomerization catalyst.

16.
Metab Eng ; 80: 130-141, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37734652

ABSTRACT

The establishment of a bio-based circular economy is imperative in tackling the climate crisis and advancing sustainable development. In this realm, the creation of microbial cell factories is central to generating a variety of chemicals and materials. The design of metabolic pathways is crucial in shaping these microbial cell factories, especially when it comes to producing chemicals with yet-to-be-discovered biosynthetic routes. To aid in navigating the complexities of chemical and metabolic domains, computer-supported tools for metabolic pathway design have emerged. In this paper, we evaluate how digital strategies can be employed for pathway prediction and enzyme discovery. Additionally, we touch upon the recent strides made in using deep learning techniques for metabolic pathway prediction. These computational tools and strategies streamline the design of metabolic pathways, facilitating the development of microbial cell factories. Leveraging the capabilities of deep learning in metabolic pathway design is profoundly promising, potentially hastening the advent of a bio-based circular economy.


Subject(s)
Deep Learning , Metabolic Engineering , Metabolic Engineering/methods , Metabolic Networks and Pathways/genetics
17.
Nat Commun ; 14(1): 5304, 2023 08 31.
Article in English | MEDLINE | ID: mdl-37652926

ABSTRACT

Vitamin B6 is an essential nutrient with extensive applications in the medicine, food, animal feed, and cosmetics industries. Pyridoxine (PN), the most common commercial form of vitamin B6, is currently chemically synthesized using expensive and toxic chemicals. However, the low catalytic efficiencies of natural enzymes and the tight regulation of the metabolic pathway have hindered PN production by the microbial fermentation process. Here, we report an engineered Escherichia coli strain for PN production. Parallel pathway engineering is performed to decouple PN production and cell growth. Further, protein engineering is rationally designed including the inefficient enzymes PdxA, PdxJ, and the initial enzymes Epd and Dxs. By the iterative multimodule optimization strategy, the final strain produces 1.4 g/L of PN with productivity of 29.16 mg/L/h by fed-batch fermentation. The strategies reported here will be useful for developing microbial strains for the production of vitamins and other bioproducts having inherently low metabolic fluxes.


Subject(s)
Escherichia coli Proteins , Pyridoxine , Animals , Vitamin B 6 , Vitamins , Protein Engineering , Escherichia coli/genetics , Ligases , Escherichia coli Proteins/genetics
18.
Nat Commun ; 14(1): 5177, 2023 08 24.
Article in English | MEDLINE | ID: mdl-37620358

ABSTRACT

Adenosylcobalamin (AdoCbl), a biologically active form of vitamin B12 (coenzyme B12), is one of the most complex metal-containing natural compounds and an essential vitamin for animals. However, AdoCbl can only be de novo synthesized by prokaryotes, and its industrial manufacturing to date was limited to bacterial fermentation. Here, we report a method for the synthesis of AdoCbl based on a cell-free reaction system performing a cascade of catalytic reactions from 5-aminolevulinic acid (5-ALA), an inexpensive compound. More than 30 biocatalytic reactions are integrated and optimized to achieve the complete cell-free synthesis of AdoCbl, after overcoming feedback inhibition, the complicated detection, instability of intermediate products, as well as imbalance and competition of cofactors. In the end, this cell-free system produces 417.41 µg/L and 5.78 mg/L of AdoCbl using 5-ALA and the purified intermediate product hydrogenobyrate as substrates, respectively. The strategies of coordinating synthetic modules of complex cell-free system describe here will be generally useful for developing cell-free platforms to produce complex natural compounds with long and complicated biosynthetic pathways.


Subject(s)
Vitamin B 12 , Vitamins , Animals , Cell-Free System , Aminolevulinic Acid , Biocatalysis
19.
Metab Eng ; 79: 78-85, 2023 09.
Article in English | MEDLINE | ID: mdl-37451533

ABSTRACT

Valerolactam (VL) is an important precursor chemical for nylon-5 and nylon 6,5. It has been produced by petroleum-based route involving harsh reaction conditions and generating toxic wastes. Here, we report the complete biosynthesis of VL by metabolically engineered Corynebacterium glutamicum overproducing L-lysine. The pathway comprising L-lysine monooxygenase (davB) and 5-aminovaleramide amidohydrolase (davA) from Pseudomonas putida, and ß-alanine CoA transferase (act) from Clostridium propionicum was introduced into the C. glutamicum GA16 strain. To increase the VL flux, competitive pathways predicted from sRNA knockdown target screening were deleted. This engineered C. glutamicum strain produced VL as a major product, but still secreted significant amount of its precursor, 5-aminovaleric acid (5AVA). To circumvent this problem, putative 5AVA transporter genes were screened and engineered in the genome, thereby reuptaking 5AVA excreted. Also, multiple copies of the act gene were integrated into the genome to strengthen the conversion of 5AVA to VL. The final VL10 (pVL1) strain was constructed by enhancing glucose uptake system, which produced 9.68 g/L of VL in flask culture. Fed-batch fermentation of the VL10 (pVL1) strain produced 76.1 g/L of VL from glucose with the yield and productivity of 0.28 g/g and 0.99 g/L/h, respectively, showcasing a high potential for bio-based production of VL from renewable resources.


Subject(s)
Corynebacterium glutamicum , Corynebacterium glutamicum/genetics , Corynebacterium glutamicum/metabolism , Nylons/metabolism , Metabolic Engineering , Lactams/metabolism , Fermentation
20.
ACS Synth Biol ; 12(8): 2353-2366, 2023 08 18.
Article in English | MEDLINE | ID: mdl-37402223

ABSTRACT

CRISPR tools, especially Cas9n-sgRNA guided cytidine deaminase base editors such as CRISPR-BEST, have dramatically simplified genetic manipulation of streptomycetes. One major advantage of CRISPR base editing technology is the possibility to multiplex experiments in genomically instable species. Here, we demonstrate scaled up Csy4 based multiplexed genome editing using CRISPR-mcBEST in Streptomyces coelicolor. We evaluated the system by simultaneously targeting 9, 18, and finally all 28 predicted specialized metabolite biosynthetic gene clusters in a single experiment. We present important insights into the performance of Csy4 based multiplexed genome editing at different scales. Using multiomics analysis, we investigated the systems wide effects of such extensive editing experiments and revealed great potentials and important bottlenecks of CRISPR-mcBEST. The presented analysis provides crucial data and insights toward the development of multiplexed base editing as a novel paradigm for high throughput engineering of Streptomyces chassis and beyond.


Subject(s)
Actinomycetales , Gene Editing , CRISPR-Cas Systems/genetics , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , RNA, Guide, CRISPR-Cas Systems , Actinomycetales/genetics , Systems Analysis
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