Systems biology approach for enhancing limonene yield by re-engineering Escherichia coli.

Engineered microorganisms have emerged as viable alternatives for limonene production. However, issues such as low enzyme abundance or activities, and regulatory feedback/forward inhibition may reduce yields. To understand the underlying metabolism, we adopted a systems biology approach for an engineered limonene-producing Escherichia coli strain K-12 MG1655.

IL-1β promotes esophageal squamous cell carcinoma growth and metastasis through FOXO3A by activating the PI3K/AKT pathway.

Esophageal cancer is a common type of cancer that poses a significant threat to human health. While the pro-inflammatory cytokine IL-1β has been known to contribute to the development of various types of tumors, its role in regulating esophageal cancer progression has not been extensively studied. Our studies found that the expression of IL-1β and FOXO3A was increased in esophageal squamous cell carcinoma (ESCC).

Breakthrough infection elicits hypermutated IGHV3-53/3-66 public antibodies with broad and potent neutralizing activity against SARS-CoV-2 variants including the emerging EG.5 lineages.

The rapid emergence of SARS-CoV-2 variants of concern (VOCs) calls for efforts to study broadly neutralizing antibodies elicited by infection or vaccination so as to inform the development of vaccines and antibody therapeutics with broad protection. Here, we identified two convalescents of breakthrough infection with relatively high neutralizing titers against all tested viruses. Among 50 spike-specific monoclonal antibodies (mAbs) cloned from their B cells, the top 6 neutralizing mAbs (KXD01-06) belong to previously defined IGHV3-53/3-66 public antibodies.

Advances and applications of CRISPR/Cas-mediated interference in .

The bacterium () is one of the most widely used chassis microbes employed for the biosynthesis of numerous valuable chemical compounds. In the past decade, the metabolic engineering of has undergone significant advances, although further productivity improvements will require extensive genome modification, multi-dimensional regulation, and multiple metabolic-pathway coordination. In this context, clustered regularly interspaced short palindromic repeats (CRISPR), along with CRISPR-associated protein (Cas) and its inactive variant (dCas), have emerged as notable recombination and transcriptional regulation tools that are particularly useful for multiplex metabolic engineering in .

Mutagenesis of Dimer Interfacial Residues Improves the Activity and Specificity of Methyltransferase for -α-Irone Biosynthesis.

Promiscuous enzymes show great potential to establish new-to-nature pathways and expand chemical diversity. Enzyme engineering strategies are often employed to tailor such enzymes to improve their activity or specificity. It is paramount to identify the target residues to be mutated.

High-Yield Biosynthesis of -Nerolidol from Sugar and Glycerol.

Isoprenoids, or terpenoids, have wide applications in food, feed, pharmaceutical, and cosmetic industries. Nerolidol, an acyclic C15 isoprenoid, is widely used in cosmetics, food, and personal care products. Current supply of nerolidol is mainly from plant extraction that is inefficient, costly, and of inconsistent quality.

β-Cryptoxanthin Production in by Optimization of the Cytochrome P450 CYP97H1 Activity.

Cytochromes P450, forming a superfamily of monooxygenases containing heme as a cofactor, show great versatility in substrate specificity. Metabolic engineering can take advantage of this feature to unlock novel metabolic pathways. However, the cytochromes P450 often show difficulty being expressed in a heterologous chassis.

Cytochrome P450 Surface Domains Prevent the β-Carotene Monohydroxylase CYP97H1 of from Acting as a Dihydroxylase.

Molecular biodiversity results from branched metabolic pathways driven by enzymatic regioselectivities. An additional complexity occurs in metabolites with an internal structural symmetry, offering identical extremities to the enzymes. For example, in the terpene family, β-carotene presents two identical terminal closed-ring structures.

Micro-Image Strain Sensing Method for Displacement and Strain Measurement in One United Sensor.

Micro-image strain sensing (MISS) is an innovative technology to measure strain within a measurement range of ±8300 microstrains. It has been proved to be effective and satisfy all requirements in the field of structural health monitoring. However, there is still room for improvement and extend the range of measurement.

Total enzymatic synthesis of cis-α-irone from a simple carbon source.

Metabolic engineering has become an attractive method for the efficient production of natural products. However, one important pre-requisite is to establish the biosynthetic pathways. Many commercially interesting molecules cannot be biosynthesized as their native biochemical pathways are not fully elucidated.

Mediating oxidative stress enhances α-ionone biosynthesis and strain robustness during process scaling up.

Background: α-Ionone is highly valued in cosmetics and perfumery with a global usage of 100-1000 tons per year. Metabolic engineering by microbial fermentation offers a promising way to produce natural (R)-α-ionone in a cost-effective manner. Apart from optimizing the metabolic pathways, the approach is also highly dependent on generating a robust strain which retains productivity during the scale-up process.

Sustainable biosynthesis of valuable diterpenes in microbes.

Diterpenes, or diterpenoids, are the most abundant and diverse subgroup of terpenoids, the largest family of secondary metabolites. Most diterpenes possess broad biological activities including anti-inflammatory, antiviral, anti-tumoral, antimicrobial, anticancer, antifungal, antidiabetic, cardiovascular protective, and phytohormone activities. As such, diterpenes have wide applications in medicine (e.

SOFA Score in relation to Sepsis: Clinical Implications in Diagnosis, Treatment, and Prognostic Assessment.

Purpose: To analyze the clinical significance of the sequential organ failure assessment (SOFA) score in the diagnosis, treatment, and prognostic assessment of sepsis.

Methods: 140 patients with sepsis from January 2020 to January 2021 were selected as the observation group, and 40 healthy people were selected as the control group. The observation group was divided into mild group, severe group, and septic shock group by single blind grouping according to the condition of the disease, and they were also divided into survival group and death group according to the prognosis.

Early Diagnosis and Prediction of Death Risk in Patients with Sepsis by Combined Detection of Serum PCT, BNP, Lactic Acid, and Apache II Score.

In order to investigate the expression levels of procalcitonin (PCT), B-type brain natriuretic peptide (BNP), and lactic acid (Lac) in serum of patients with sepsis, a retrospective analysis is conducted. 80 sepsis patients admitted to the ICU of our hospital from January 2019 to June 2020 are selected, and the application value of these factors combined with Apache II score in early diagnosis and prediction of death risk is analyzed. All patients are classified into survival group ( = 57) and death group ( = 23), and examined by blood routine.

Metabolic engineering of Escherichia coli BL21 strain using simplified CRISPR-Cas9 and asymmetric homology arms recombineering.

Background: The recent CRISPR-Cas coupled with λ recombinase mediated genome recombineering has become a common laboratory practice to modify bacterial genomes. It requires supplying a template DNA with homology arms for precise genome editing. However, generation of homology arms is a time-consuming, costly and inefficient process that is often overlooked.

Biotechnological applications of S-adenosyl-methionine-dependent methyltransferases for natural products biosynthesis and diversification.

In the biosynthesis of natural products, methylation is a common and essential transformation to alter molecules' bioavailability and bioactivity. The main methylation reaction is performed by S-adenosylmethionine (SAM)-dependent methyltransferases (MTs). With advancements in genomic and chemical profiling technologies, novel MTs have been discovered to accept complex substrates and synthesize industrially valuable natural products.

High-level de novo biosynthesis of glycosylated zeaxanthin and astaxanthin in Escherichia coli.

Because of wide applications in food, feed, pharmaceutical and cosmetic industries, the carotenoid market is growing rapidly. Most carotenoids are hydrophobic, which limits their bioavailability. Glycosylation is a natural route that substantially increases the water solubility, as well as the bioavailability, photostability and biological activities of carotenoids.

Bioinformatics-aided identification, characterization and applications of mushroom linalool synthases.

Enzymes empower chemical industries and are the keystone for metabolic engineering. For example, linalool synthases are indispensable for the biosynthesis of linalool, an important fragrance used in 60-80% cosmetic and personal care products. However, plant linalool synthases have low activities while expressed in microbes.

Microbial astaxanthin biosynthesis: recent achievements, challenges, and commercialization outlook.

Astaxanthin is a natural pigment, known for its strong antioxidant activity and numerous health benefits to human and animals. Its antioxidant activity is known to be substantially greater than β-carotene and about a thousand times more effective than vitamin E. The potential health benefits have generated a growing commercial interest, and the escalating demand has prompted the exploration of alternative supply chain.

Serves As a Gateway for Identifying Sesquiterpene Biosynthetic Enzymes in Higher Fungi.

Terpenoids constitute a structurally diverse group of natural products with wide applications in the pharmaceutical, nutritional, flavor and fragrance industries. Fungi are known to produce a large variety of terpenoids, yet fungal terpene synthases remain largely unexploited. Here, we report the sesquiterpene network and gene clusters of the black poplar mushroom Among 11 putative sesquiterpene synthases (STSs) identified in its genome, nine are functional, including two novel synthases producing viridiflorol and viridiflorene.

Metabolic Engineering Strategies for Sustainable Terpenoid Flavor and Fragrance Synthesis.

Terpenoids derived from plant material are widely applied in the flavor and fragrance industry. Traditional extraction methods are unsustainable, but microbial synthesis offers a promising solution to attain efficient production of natural-identical terpenoids. Overproduction of terpenoids in microbes requires careful balancing of the synthesis pathway constituents within the constraints of host cell metabolism.

Effective Data-Aware Covariance Estimator From Compressed Data.

Estimating covariance matrix from massive high-dimensional and distributed data is significant for various real-world applications. In this paper, we propose a data-aware weighted sampling-based covariance matrix estimator, namely DACE, which can provide an unbiased covariance matrix estimation and attain more accurate estimation under the same compression ratio. Moreover, we extend our proposed DACE to tackle multiclass classification problems with theoretical justification and conduct extensive experiments on both synthetic and real-world data sets to demonstrate the superior performance of our DACE.

Systematic engineering for high-yield production of viridiflorol and amorphadiene in auxotrophic Escherichia coli.

Isoprenoids, widely used as pharmaceuticals, flavors and nutraceuticals, represent one of the largest groups of natural products. Yet the low availability of top-quality (enantiopure) products and high cost limit the wide application of many valuable terpenoids. An example being viridiflorol, currently used in cosmetics and personal care products, may have other unexplored applications (e.

Integrating Enzyme and Metabolic Engineering Tools for Enhanced α-Ionone Production.

Metabolic engineering aims to balance intracellular pathways and increase the precursor supply. However, some heterologous enzymes are not evolved to support high flux. To remove the limitation, the catalytic properties of rate-limiting enzymes must be enhanced.

Multidimensional heuristic process for high-yield production of astaxanthin and fragrance molecules in Escherichia coli.

Optimization of metabolic pathways consisting of large number of genes is challenging. Multivariate modular methods (MMMs) are currently available solutions, in which reduced regulatory complexities are achieved by grouping multiple genes into modules. However, these methods work well for balancing the inter-modules but not intra-modules.