Enhanced molecular stability of ApxII antigen during secretion in Corynebacterium glutamicum by rational design.

ApxII is a vaccine antigen used to protect against porcine contagious pleuropneumonia, which is a significant threat to the pig industry. Here, we aimed to improve the proteolytic degradation stability of ApxII during its secretion by establishing a complete screening process of stable variants through bioinformatics and site-directed mutagenesis. We employed a combination of semi-rational and rational design strategies to create 34 single-point variants of ApxII.

Microbial conversion of ethanol to high-value products: progress and challenges.

Industrial biotechnology heavily relies on the microbial conversion of carbohydrate substrates derived from sugar- or starch-rich crops. This dependency poses significant challenges in the face of a rising population and food scarcity. Consequently, exploring renewable, non-competing carbon sources for sustainable bioprocessing becomes increasingly important.

Bacterial surface display of PETase mutants and MHETase for an efficient dual-enzyme cascade catalysis.

Biological degradation of PET plastic holds great potential for plastic recycling. However, the high costs associated with preparing free enzymes for degrading PET make it unfeasible for industrial applications. Hence, we developed various cell catalysts by surface-displaying PETase mutants and MHETase using autotransporters in E.

Recent advances in lycopene and germacrene a biosynthesis and their role as antineoplastic drugs.

Sesquiterpenes and tetraterpenes are classes of plant-derived natural products with antineoplastic effects. While plant extraction of the sesquiterpene, germacrene A, and the tetraterpene, lycopene suffers supply chain deficits and poor yields, chemical synthesis has difficulties in separating stereoisomers. This review highlights cutting-edge developments in producing germacrene A and lycopene from microbial cell factories.

Continuous catalytic production of 1,3-dihydroxyacetone: Sustainable approach combining perfusion cultures and immobilized cells.

Currently, the predominant method for the industrial production of 1,3-dihydroxyacetone (DHA) from glycerol involves fed-batch fermentation. However, previous research has revealed that in the biocatalytic synthesis of DHA from glycerol, when the DHA concentration exceeded 50 g·L, it significantly inhibited microbial growth and metabolism, posing a challenge in maintaining prolonged and efficient catalytic production of DHA. In this study, a new integrated continuous production and synchronous separation (ICSS) system was constructed using hollow fiber columns and perfusion culture technology.

Application of Multivariate Data Analysis on Historical Recombinant Adenovirus Zoster Vaccine Production Data for Upstream Process Improvements.

In recent years, multivariate data analysis (MVDA) has been widely used for process characterization and fault diagnosis in the biopharmaceutical industry. This study aims to investigate the feasibility of using MVDA for the development and scale-up of a perfusion process for HEK293 cell-based recombinant adenovirus zoster vaccine (Ad-HER) production. The Principal Component Analysis (PCA) results suggested comparable performance among the ATF, PATFP, and BFP perfusion systems in benchtop-scale stirred-tank bioreactor (STR).

The murein endopeptidase MepA regulated by MtrAB and MprAB participate in cell wall homeostasis.

The complete genome of Corynebacterium glutamicum contain a gene encoding murein endopeptidase MepA which maintain cell wall homeostasis by regulating peptidoglycan biosynthesis. In this study, we investigate the physiological function, localization and regulator of MepA. The result shows that mepA overexpression lead to peptidoglycan degradation and the defects in cell division.

Hyper-production of porcine contagious pleuropneumonia subunit vaccine proteins in Escherichia coli by developing a bicistronic T7 expression system.

The ApxII toxin and the outer membrane lipoprotein (Oml) of Actinobacillus pleuropneumoniae are important vaccine antigens against porcine contagious pleuropneumonia (PCP), a prevalent infectious disease affecting the swine industry worldwide. Previous studies have reported the recombinant expression of ApxII and Oml in Escherichia coli; however, their yields were not satisfactory. Here, we aimed to enhance the production of ApxII and Oml by constructing a bicistronic expression system based on the widely used T7 promoter.

Development and characterization of anti-IL-5 monoclonal antibody Fab fragment for blocking IL-5/IL-5Rα binding.

Interleukin-5 (IL-5) is a homodimeric cytokine that is a crucial regulator of the proliferation, activation, and maturation of eosinophils. Anti-IL-5 monoclonal antibodies, which block the binding of IL-5 to the IL-5 receptor subunit alpha (IL-5Rα), have been successfully used to treat eosinophilic (EOS) asthma. The currently marketed monoclonal antibody drugs require repeated injections for administration, which seriously affect patient compliance and high systemic exposure for injectable drug delivery.

Creating NADP -Specific Formate Dehydrogenases from Komagataella phaffii by Enzymatic Engineering.

Most natural formate dehydrogenases (FDHs) exhibit NAD specificity, making it imperative to explore the engineering of FDH cofactor specificity for NADPH regeneration systems. The endogenous FDH of Komagataella phaffii (K. phaffii), termed KphFDH, is a typical NAD -specific FDH.

High-throughput process development from gene cloning to protein production.

In the post-genomic era, the demand for faster and more efficient protein production has increased, both in public laboratories and industry. In addition, with the expansion of protein sequences in databases, the range of possible enzymes of interest for a given application is also increasing. Faced with peer competition, budgetary, and time constraints, companies and laboratories must find ways to develop a robust manufacturing process for recombinant protein production.

[Hyperosmotic stress and perfusion culture strategies increase the yield of recombinant adenoviral vector produced by HEK 293 cells].

With various diseases ravaging internationally, the demands for recombinant adenoviral vector (Adv) vaccines have increased dramatically. To meet the demand for Adv vaccine, development of a new cell culture process is an effective strategy. Applying hyperosmotic stress in cells before virus infection could increase the yield of Adv in batch culture mode.

Improved Membrane Permeability via Hypervesiculation for Recovery of Lycopene in .

Lycopene biosynthesis is frequently hampered by downstream processing hugely due to its inability to be secreted out from the producing chassis. Engineering cell factories can resolve this issue by secreting this hydrophobic compound. A highly permeable strain was developed for a better release rate of lycopene.

Plasmid Copy Number Engineering Accelerates Fungal Polyketide Discovery upon Unnatural Polyketide Biosynthesis.

has been extensively used as a convenient synthetic biology chassis to reconstitute fungal polyketide biosynthetic pathways. Despite progress in refactoring these pathways for expression and optimization of the yeast production host by metabolic engineering, product yields often remain unsatisfactory. Such problems are especially acute when synthetic biological production is used for bioprospecting via genome mining or when chimeric fungal polyketide synthases (PKSs) are employed to produce novel bioactive compounds.

Longitudinal analysis of memory Tfh cells and antibody response following CoronaVac vaccination.

The inactivated vaccine CoronaVac is one of the most widely used COVID-19 vaccines globally. However, the longitudinal evolution of the immune response induced by CoronaVac remains elusive compared with other vaccine platforms. Here, we recruited 88 healthy individuals who received 3 doses of CoronaVac vaccine.

Leaderless Bicistronic Design for Precise and Reliable Control of Gene Expression in .

In synthetic biology, the precise control of gene expression is challenging due to the limited orthogonality of expression elements. Here, to address this issue and improve the reusability of genetic elements, we developed a bicistronic expression cassette in based on a leaderless promoter lacking a 5'UTR. The created leaderless bicistronic design (BCD) significantly improved the orthogonality of expression elements across different genes of interest.

Engineering Escherichia coli BL21 (DE3) for high-yield production of germacrene A, a precursor of β-elemene via combinatorial metabolic engineering strategies.

β-elemene is one of the most commonly used antineoplastic drugs in cancer treatment. As a plant-derived natural chemical, biologically engineering microorganisms to produce germacrene A to be converted to β-elemene harbors great expectations since chemical synthesis and plant isolation methods come with their production deficiencies. In this study, we report the design of an Escherichia coli cell factory for the de novo production of germacrene A to be converted to β-elemene from a simple carbon source.

Direct Utilization of Peroxisomal Acetyl-CoA for the Synthesis of Polyketide Compounds in .

Polyketides are a class of natural products with many applications but are mainly appealing as pharmaceuticals. Heterologous production of polyketides in the yeast has been widely explored because of the many merits of this model eukaryotic microorganism. Although acetyl-CoA and malonyl-CoA, the precursors for polyketide synthesis, are distributed in several yeast subcellular organelles, only cytosolic synthesis of polyketides has been pursued in previous studies.

Enhanced production of recombinant proteins in Corynebacterium glutamicum using a molecular chaperone.

Protein synthesis in Corynebacterium glutamicum is critical for applications in biotechnology and medicine. However, the use of C. glutamicum for protein production is limited by its low expression and aggregation.

CRISPRi-microfluidics screening enables genome-scale target identification for high-titer protein production and secretion.

Genome-scale target identification promises to guide microbial cell factory engineering for higher-titer production of biomolecules such as recombinant proteins (r-protein), but challenges remain due to the need not only for comprehensive genotypic perturbation but also in conjunction with high-throughput phenotypic screening strategies. Here, we developed a CRISPRi-microfluidics screening platform to systematically identify crucial gene targets that can be engineered to enhance r-protein secretion in Corynebacterium glutamicum. We created a CRISPR interference (CRISPRi) library containing 46,549 single-guide RNAs, where we aimed to unbiasedly target all genes for repression.

Metabolic Engineering Mevalonate Pathway Mediated by RNA Scaffolds for Mevalonate and Isoprene Production in .

Co-localizing biochemical processes is a great strategy when expressing the heterologous metabolic pathway for product biosynthesis. The RNA scaffold is a flexible and efficient synthetic compartmentalization method to co-localize the enzymes involved in the metabolic pathway by binding to the specific RNA, binding domains fused with the engineered enzymes. Herein, we designed two artificial RNA scaffold structures─0D RNA scaffolds and 2D RNA scaffolds─using the reported aptamers PP7 and BIV-Tat and the corresponding RNA-binding domains (RBDs).

Optimization of an adenovirus-vectored zoster vaccine production process with chemically defined medium and a perfusion system.

Objectives: Cells grown in chemically defined medium are sensitive to shear force, potentially resulting in decreased cell growth. We optimized the perfusion process for HEK293 cell-based recombinant adenovirus-vectored zoster vaccine (Ad-HER) production with chemically defined medium.

Methods: We first studied the pseudo-continuous strategies in shake flasks as a mimic of the bioreactor equipped with perfusion systems.

Immobilization of D-allulose 3-epimerase into magnetic metal-organic framework nanoparticles for efficient biocatalysis.

D-allulose is a rare low-calorie sugar that has many fundamental biological functions. D-allulose 3-epimerase from Agrobacterium tumefaciens (AT-DAEase) catalyzes the conversion of D-fructose to D-allulose. The enzyme has attracted considerable attention because of its mild catalytic properties.

Advances in the Study of Inhaled Formulations for the Treatment of Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a serious disease with reduced systemic circulation and low bioavailability associated with conventional and dosed therapy, which inhaled drugs can avoid. A mean pulmonary artery pressure (mPAP) of ≥25 mmHg (1 mmHg = 0.133 kPa) at rest or ≥30 mmHg during exercise and a pulmonary capillary pressure or left atrial pressure (PLA) of ≤15 mmHg can be diagnosed with PAH.