Publications by authors named "Jay D Keasling"

Rationale: Viral lung infections are a major cause of morbidity and mortality worldwide. Despite significant advances in vaccines and antivirals, there remains a tremendous need for broadly applicable treatments that can be utilized across viral infections. Prior to infecting epithelial cells, viruses interact with the epithelial glycocalyx, which contains high molecular weight hyaluronan (HMWHA), a glycosaminoglycan that has beneficial effects in lung injury.

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Isoprenoids are a diverse class of natural products that are essential in all domains of life. Most bacteria synthesize isoprenoids through either the methylerythritol phosphate (MEP) pathway or the mevalonate (MEV) pathway, while a small subset encodes both pathways, including the pathogen (Mm). It is unclear whether the MEV pathway is functional in Mm, or why Mm encodes seemingly redundant metabolic pathways.

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There is an urgent need to develop a more efficacious anti-tuberculosis vaccine as the current live-attenuated vaccine strain BCG fails to prevent pulmonary infection in adults. Our long-term goal is to test whether increasing the immunogenicity of BCG will improve vaccine effectiveness while maintaining its proven safety profile. In this study, we leverage a synthetic biology approach to engineer BCG to produce more (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), a phosphoantigen produced as an intermediate of bacterial-but not host-isoprenoid biosynthesis via the methylerythritol phosphate (MEP) pathway.

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Synthetic biology offers the promise of manufacturing chemicals more sustainably than petrochemistry. Yet, both the rate at which biomanufacturing can synthesize these molecules and the net chemical accessible space are limited by existing pathway discovery methods, which can often rely on arduous literature searches. Here, we introduce BioPKS pipeline, an automated retrobiosynthesis tool combining multifunctional type I polyketide synthases (PKSs) and monofunctional enzymes via two complementary tools: RetroTide and DORAnet.

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Microbial bioproduction using one-carbon (C1) feedstocks has the potential to decarbonize the manufacturing of materials, fuels, and chemicals. Formate is a promising C1 feedstock, and the realization of industrial, formatotrophic platform organisms is a key goal for C1-based bioproduction. So far, a major limitation for synthetic formatotrophy has been slow energy supply due to slow formate dehydrogenase activity.

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Covering: 2020 to 2025Natural products remain indispensable sources of therapeutic and bioactive compounds, yet traditional discovery strategies are constrained by compound rediscovery. Modular biosynthetic enzymes, such as type I polyketide synthases (PKSs) and type A non-ribosomal peptide synthetases (NRPSs), offer promising platforms for combinatorial biosynthesis owing to their programmable architectures. However, practical implementation is frequently limited by inter-modular incompatibility and domain-specific interactions.

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NRRL 18488, the primary producer of the immunosuppressant FK506, was analyzed to elucidate regulatory features of secondary metabolism. Completion of its 7.9-Mb linear genome enabled accurate re-annotation of the FK506 biosynthetic gene cluster (BGC).

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Heterologous expression of polyketide synthase (PKS) genes in Escherichia coli has enabled the production of various valuable natural and synthetic products. However, the limited availability of malonyl-CoA (M-CoA) in E. coli remains a substantial impediment to high-titer polyketide production.

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Machine learning has revolutionized drug discovery by enabling the exploration of vast, uncharted chemical spaces essential for discovering novel patentable drugs. Despite the critical role of human G protein-coupled receptors in FDA-approved drugs, exhaustive in-distribution drug-target interaction testing across all pairs of human G protein-coupled receptors and known drugs is rare due to significant economic and technical challenges. This often leaves off-target effects unexplored, which poses a considerable risk to drug safety.

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Although synthetic biology can produce valuable chemicals in a renewable manner, its progress is still hindered by a lack of predictive capabilities. Media optimization is a critical, and often overlooked, process which is essential to obtain the titers, rates and yields needed for commercial viability. Here, we present a molecule- and host-agnostic active learning process for media optimization that is enabled by a fast and highly repeatable semi-automated pipeline.

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Engineered type I polyketide synthases (T1PKSs) are a potentially transformative platform for the biosynthesis of small molecules. Due to their modular nature, T1PKSs can be rationally designed to produce a wide range of bulk or specialty chemicals. While heterologous PKS expression is best studied in microbes of the genus , recent studies have focused on the exploration of non-native PKS hosts.

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Biotechnology offers a sustainable route to manufacturing, but closing the loop towards safeguarding biodiversity remains challenging. Here, we explore how partnerships with Indigenous Peoples and Local Communities (IP&LC) can promote an ethical and circular bioeconomy.

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Converting polyethylene (PE) into valuable materials, particularly ones that are better for the environment than the incumbent plastics, not only helps mitigate environmental issues caused by plastic waste but also alleviates the long-standing problem of microbial fermentation competing with food supplies. However, the inherent robustness of PE due to its strong carbon-carbon bonds and high molecular weight necessitates harsh decomposition conditions, resulting in diverse decomposition outcomes that present significant challenges for downstream applications, especially for bioconversion. In this study, we demonstrate a hybrid biological-chemical conversion process for PE, converting its decomposition products, namely short-chain diacids, into a monomer, β-keto-δ-lactone (BKDL), for highly recyclable polydiketoenimine plastics using engineered Corynebacterium glutamicum.

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Prenol and isoprenol are promising advanced biofuels and serve as biosynthetic precursors for pharmaceuticals, fragrances, and other industrially relevant compounds. Despite engineering improvements that circumvent intermediate cytotoxicity and lower energy barriers, achieving high titer 'mevalonate (MVA)-derived' prenol has remained elusive. Difficulty in selective prenol production stems from the necessary isomerization of isopentenyl diphosphate (IPP) to dimethylallyl diphosphate (DMAPP) as well as the intrinsic toxicity of these diphosphate precursors.

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10-hydroxy-2-decenoic acid (10-HDA), a unique unsaturated fatty acid present in royal jelly, has attracted considerable interest due to its potential medical applications. However, its low concentration in royal jelly and complex conformational structure present challenges for large-scale production. In this study, we designed and constructed a de novo biosynthetic pathway for 10-HDA in Escherichia coli.

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The copy number of a plasmid is linked to its functionality, yet there have been few attempts to optimize higher-copy-number mutants for use across diverse origins of replication in different hosts. We use a high-throughput growth-coupled selection assay and a directed evolution approach to rapidly identify origin of replication mutations that influence copy number and screen for mutants that improve Agrobacterium-mediated transformation (AMT) efficiency. By introducing these mutations into binary vectors within the plasmid backbone used for AMT, we observe improved transient transformation of Nicotiana benthamiana in four diverse tested origins (pVS1, RK2, pSa and BBR1).

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Article Synopsis
  • Monoterpene indole alkaloids (MIAs) from the kratom plant, like mitragynine and speciogynine, show potential for treating pain and addiction, with a complex historical use in Southeast Asia as pain relief and a stimulant.* -
  • The researchers successfully engineered yeast (Saccharomyces cerevisiae) to produce these MIAs by reconstructing a synthetic pathway that converts a precursor compound, achieving a yield of around 290 μg/L.* -
  • The study also opens up avenues for optimizing production further and creating new derivatives of mitragynine with potential uses in drug development, establishing a platform for biomanufacturing these compounds.*
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Fungal fermentation of food and agricultural by-products holds promise for improving food sustainability and security. However, the molecular basis of fungal waste-to-food upcycling remains poorly understood. Here we use a multi-omics approach to characterize oncom, a fermented food traditionally produced from soymilk by-products in Java, Indonesia.

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Promoter-centric genetic tools play a crucial role in controlling gene expression for various applications, such as strain engineering and synthetic biology studies. Hence, a critical need persists for the development of robust gene expression tools. are well-known prolific producers of natural products and exceptional surrogate hosts for the production of high-value chemical compounds and enzymes.

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Article Synopsis
  • Sunscreen has a long history of use for skin protection, but modern ingredients like oxybenzone and ZnO raise health and environmental concerns.
  • This study focuses on creating a microbial platform using Pseudomonas putida to produce shinorine, a compound that absorbs UV light and has anti-aging benefits.
  • Researchers used advanced techniques such as CRISPRi, biosynthetic pathway optimization, and amino acid feeding experiments to enhance shinorine production and identify key factors influencing its yield.
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Glycosylation is a ubiquitous modification present across all of biology, affecting many things such as physicochemical properties, cellular recognition, subcellular localization, and immunogenicity. Nucleotide sugars are important precursors needed to study glycosylation and produce glycosylated products. is a potentially powerful platform for producing glycosylated biomolecules, but it lacks nucleotide sugar diversity.

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Article Synopsis
  • QS-21 is a clinically approved saponin-based vaccine adjuvant, but its extraction is challenging due to its complex structure and limited supply from natural sources or low-yield chemical synthesis.
  • Researchers have achieved the complete biosynthesis of QS-21 and its precursors in engineered yeast strains by carefully tuning the yeast's metabolic pathways and expressing 38 foreign enzymes from six different organisms.
  • This innovative microbial production method not only simplifies the production of QS-21 but also allows for the creation of structural analogues, paving the way for improved vaccine adjuvant design based on structure-activity relationships.
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Natural products have played significant roles as medicine and food throughout human history. Here, we first provide a brief historical overview of natural products, their classification and biosynthetic origins, and the microbiological and genetic methods used for their discovery. We also describe and discuss the technologies that revolutionized the field, which transitioned from classic genetics to genome-centric discovery approximately two decades ago.

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