New Biotechnology

The rapid emergence of SARS-CoV-2 variants that evade neutralizing antibodies underscores the need for next-generation antiviral biologics that combine molecular precision with scalable, cost-effective manufacturing. Computationally designed miniproteins targeting the receptor-binding domain (RBD) of the spike protein offer a compelling alternative to monoclonal antibodies due to their small size, high thermal stability, and compatibility with microbial expression systems. Here we report the end-to-end development and cGMP production of IPD-52520, a de novo antiviral miniprotein, using an optimized E. coli platform. Two miniprotein candidates, a homotrimeric construct (Trimer is referred to as IPD-52520, 17 kDa) and a tandem fusion (Daisy is referred to as IPD-52521, 25 kDa), were evaluated in parallel through systematic optimization of strain selection, media composition, fed-batch fermentation, inclusion-body solubilization, refolding, and chromatographic purification. The Trimer was downselected as the lead molecule based on superior preclinical efficacy, favorable pharmacokinetic properties, and higher volumetric manufacturing yields. The optimized process delivers approximately 2 g/L of purified protein at greater than 90% purity. Scale-up from 5 L to 50 L under cGMP conditions demonstrated excellent batch-to-batch reproducibility across six independent batches, supporting nonclinical and Phase 1 clinical supply. Comprehensive biophysical characterization confirmed a well-folded, predominantly alpha-helical trimer (Tm = 73.4 {degrees}C; polydispersity = 1.005) with an intact primary structure and strong target-binding affinity (KD < 1 pM). Real-time stability studies indicate that the drug substance is stable at 2-8 {degrees}C for at least 12 months, with ongoing stability studies. These results demonstrate the feasibility of translating computationally designed antiviral miniproteins into manufacturable biologics and provide a platform applicable to rapid-response therapeutics against current and future pandemic threats.

The successful translation of rationally designed HIV-1 immunogens into effective vaccines requires manufacturing platforms that maintain structural conformity while meeting clinical-grade quality standards. We developed and scaled a robust, cGMP-compliant process for N332-GT5 gp140, a germline-targeting envelope trimer designed to initiate broadly neutralizing antibody responses, which is now undergoing first-in-human evaluation in HVTN144. Starting with a stable CHO cell line developed using Leap-In(R) transposon technology, we established a production clone exhibiting high-titer expression (>200 mg/L) and genetic stability through 60 population doublings. The manufacturing process scaled efficiently from Ambr(R) 250 miniature bioreactors to 200-L single-use systems, delivering consistent product quality across multiple cGMP batches. A streamlined three-step purification strategy--affinity capture, multimodal polishing, and viral clearance- yielded >99% trimeric purity with preserved quaternary structure and native-like antigenicity. Orthogonal LC-MS analyses confirmed site-specific glycan occupancy matching design specifications, while robust viral clearance exceeded 18-log and 11-log reductions for model retroviruses. Clinical material manufactured through this platform has been successfully administered in HVTN144. This work establishes a scalable, reproducible manufacturing paradigm for structurally complex HIV-1 envelope immunogens, advancing the field toward rational vaccine design based on germline-targeting principles.

The purification of industrial enzymes typically relies on costly, multi-step chromatographic protocols. To address this, we developed a novel platform termed Coated Bacterial Enzymes (CBEs), which enables one-step purification and immobilization of recombinant proteins fused to the SlpA cell wall binding domain. As a proof of concept, we used a {beta}-galactosidase from Bifidobacterium bifidum of dairy relevance. The chimeric enzyme BbgII-SlpA was expressed in Escherichia coli and captured from crude lysate onto glutaraldehyde-inactivated Bacillus subtilis cells via SlpA domain. Binding was characterized by a dissociation constant (Kd) of 16.2 {micro}M and maximum binding capacity (Bmax) of 144 {micro}mol/g. The resulting CBE biocatalyst exhibited optimal activity at pH 6.0 for ONPG and lactose, with a broader pH profile than the free enzyme. Optimal temperatures were 60 {degrees}C for ONPG and 50 {degrees}C for lactose, and CBE retained >80% activity after 390 min at 45 {degrees}C, compared to 20% for the free enzyme. Catalytic efficiencies (kcat/Km) were 2.62 x106 M-1{middle dot}s-1 for ONPG and 4.40 x102 M-1{middle dot}s-1 for lactose. Moreover, CBE showed improved tolerance to cations such as Ca2+ and Fe2+. These results suggest that the CBE platform offers a cost-effective alternative for producing high-purity, immobilized enzymes for diverse industrial bioprocesses.

Recombinant adeno-associated viruses (rAAVs) have gained increasing importance in gene therapy due to their safe and precise gene delivery. However, certain indications require substantially higher vector doses, pushing manufacturing capacity and cost of goods (COG) to its limits. In this study, we present for the first time a continuous twin-column capture process (CaptureSMB) enabling direct purification of rAAV5 from unprocessed perfusion harvest without prior concentration or processing. This approach differs fundamentally from conventional batch workflows which typically mandate clarification and concentration before affinity capture and offers a novel process integration in viral vector manufacturing. A single-column batch capture process was developed first and subsequently compared to continuous CaptureSMB configurations. Optimized CaptureSMB operation achieved consistent yields over four cycles, with recoveries exceeding batch operation (+ 14.3%) with concomitant higher productivity (+ 11.4%) and reduced buffer consumption (- 79.2%). Critical quality attribute analysis showed lower host cell protein levels and lower residual DNA in early CaptureSMB cycles, while full capsid ratios, thermal stability and transduction efficiency of rAAV5 particles remained unaltered across cycles and process modes. These findings highlight that continuous twin-column CaptureSMB directly from perfusion harvest can not only improve yield and manufacturing efficiency but also maintain and in some respects enhance product quality. This novel strategy provides a promising route to address manufacturing capacity and cost challenges in rAAV gene therapy production.

Bacterial microcompartments (MCPs) are versatile proteinaceous organelles that compartmentalize metabolic pathways, offering promising scaffolds for synthetic biology and metabolic engineering. However, designing customized nanobioreactors requires distinguishing structurally indispensable shell proteins from those that can be modified or deleted to tune shell permeability without disrupting core organelle assembly. In this study, we performed a systematic biophysical and metabolic characterization of the hexameric shell protein PduU to evaluate its potential as a modular platform for synthetic organelle engineering. We tested whether deleting pduU or selectively truncating its N-terminal {beta}-barrel domain preserves shell assembly, metabolite flux, and intermediate confinement. Our results demonstrate that PduU modifications alter shell permeability while fully maintaining organelle structural integrity, monodispersity, and electrostatic colloidal stability. Crucially, this modulation in permeability redirects internal metabolic flux toward the energy-generating propionate pathway, resulting in elevated cell biomass and significantly increased yields of propionate, an economically vital industrial platform chemical. By establishing that PduU is a non-essential structural component whose modification tunes small-molecule flux, this work highlights PduU as a flexible locus for shell engineering, providing a scalable strategy for biomanufacturing of high-value bio-based products in tailor-made MCP nanobioreactors.

Raffinose family oligosaccharides (RFOs) are abundant in side streams from food and feed production from legumes, and the transition to plant-based diets increases the volume of such side streams. RFOs in the diet tend to have negative impacts on the consumers gut (e.g., nausea, bloating, diarrhoea), and in many ways, RFOs are comparable to lactose as a side stream from the dairy industry and symptoms associated with lactose intolerance. On the contrary, galactooligosaccharides (GOS) are recognized as prebiotics, and in this study we used a {beta}-galactosidase from Niallia circulans to produce potential prebiotics from RFOs (acceptors) and lactose (donor), which we hypothesized to have a lower fermentability than unmodified RFOs. The transglycosylation reactions resulted in RFO-based -{beta}-GOS, with NMR characterization showing ({beta}1-4) galactosylations on the non-reducing galactose end of RFOs as the major product. In reactions with RFOs, the characteristics were comparable to reactions with lactose alone and the new -{beta}-GOS products made up the largest fraction (by weight). A screening of 11 relevant gut and food microbe strains revealed that the gut commensal Bacteroides ovatus metabolised these modified oligosaccharides for growth whereas other strains grew only after adaption and others did not use them at all. This implies that mixed-linkage -{beta}-GOS are less fermentable by some microbes compared to raffinose, while other (beneficial) bacteria can still ferment them. The enzymatic synthesis established here is an interesting approach to upgrade abundant food side streams towards new prebiotics in a world where functional foods and food waste reduction receive increasing attention. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/731070v1_ufig1.gif" ALT="Figure 1000"> View larger version (22K): org.highwire.dtl.DTLVardef@18e0e62org.highwire.dtl.DTLVardef@1525b4borg.highwire.dtl.DTLVardef@1e7be88org.highwire.dtl.DTLVardef@18df278_HPS_FORMAT_FIGEXP M_FIG C_FIG

In liquid fermentation of filamentous fungi such as Aspergillus oryzae, increased broth viscosity and biomass adhesion to bioreactor surfaces remain major challenges. We previously developed a hyphal dispersion mutant lacking two hyphal adhesion factors, namely cell wall -1,3-glucan (AG) and biofilm galactosaminogalactan (GAG) (AG{Delta}-GAG{Delta} strain). The culture broth of the AG{Delta}-GAG{Delta} strain has low viscosity, which improves mixing and enzyme production. However, mycelia still extensively attach to bioreactor walls and downstream equipment, which impairs mixing and reduces product recovery. The hydrophobin RolA, a surface-active protein of A. oryzae, densely coats conidia and hyphae and contributes to cell surface hydrophobicity. In this study, we disrupted the rolA gene in AG{Delta}-GAG{Delta} (AG{Delta}-GAG{Delta}-{Delta}rolA strain) and evaluated the effects of this disruption on hyphal adhesion to the walls of culture vessels, enzyme production, and bioreactor performance. At the flask scale, the adhesion to glass surfaces was significantly reduced and recombinant enzyme activity was increased by 10%. Improved culture recovery at the end of fermentation further increased total enzyme yield. In a lab-scale stirred-tank bioreactor, both growth and enzyme production were increased. Scaling-up to a 200-L bioreactor showed reduced agitation power consumption while improving hydrodynamic properties. Fermentation of AG{Delta}-GAG{Delta}-{Delta}rolA was successfully scaled up to a 3000-L bioreactor; consistent enzyme activity and improved flow circulation in the bioreactors were confirmed by computational fluid dynamics analysis. Overall, the AG{Delta}-GAG{Delta}-{Delta}rolA strain has increased enzyme production and scalability, supporting its suitability for industrial applications.

The objective of this study was to enhance the production of monensin and its derivatives in Streptomyces sp. ATCC 15413. To this end the contributions of medium composition and enzyme engineering on polyketide biosynthesis were assessed. Enzyme engineering was implemented through a single-point mutation in KS5 of the polyketide synthase (PKS). This mutation increased premonensin productivity up to 29-fold, revealing and alleviating a rate-limiting step in the multi-enzyme biosynthetic pathway. Medium optimization proved comparably effective, raising titers by at least an order of magnitude across strains. Moreover, medium optimization and ketosynthase mutagenesis acted additively in the premonensin strain, further boosting its production. Overall, our findings show that medium optimization is the dominant factor in maximizing monensin yields, while enzyme engineering can deliver targeted benefits in specific contexts.

The trend towards concentrated animal feeding operations (CAFOs) has served to concentrate not only livestock animals but the waste they produce to comparatively smaller areas. The point-source nature of this waste is an opportunity for the recovery and valorization of the nitrogen therein. Such a process would be viable on small to intermediate scales and require minimal inputs at the CAFO. In this study, we demonstrate the potential of the biopolymer cyanophycin to serve as a medium for manure-nitrogen recovery. In the first step, genetically modified strains of Escherichia coli produce intracellular cyanophycin from mock manure hydrolysates. Next, cyanophycin is recovered from microbial biomass via acid solubilization and base precipitation using electrochemically generated acids and bases. Finally, to improve both the yield and recoverable fraction of cyanophycin produced, we leverage the tunability of our genetically engineered system to probe the impacts of cyanophycin synthetase solubility, N-domain activity, and cyanophycin molecular weight on cyanophycin recoverability. Collectively, this work serves as a proof of concept for nitrogen recovery from agricultural waste, aligning with global sustainability initiatives.

The increasing world population necessitates new sustainable nutrient sources, making microalgae like Chlorella sorokiniana interesting due to its rich nutrient profile and sustainable cultivation methods. With genetic optimization tools like CRISPR/Cas9, microalgae as a nutrient source can be improved even further. However, degradation of the rigid cell wall of microalgae, and thereby developing protoplasts, is often necessary prior to transformation, but monitoring protoplast development in spherical, single-celled organisms like C. sorokiniana is challenging using bright-field microscopy. Carbotrace 480 and 630 were tested as fluorescent markers of the cell wall of a C. sorokiniana mutant for protoplast detection, and Carbotrace 480 was successfully used to distinguish protoplast from normal cells in a cell suspension. The enzymes Driselase, Glucanex, Snailase, and Saczyme were tested in different combinations to degrade the cell wall of the mutant, with Snailase as the most effective yielding ~60 % protoplasts. This study provides a quick and easy tool for monitoring protoplast development in the microalgae C. sorokiniana, the first step to improve C. sorokiniana as a sustainable nutrient source using genetic optimization tools like CRISPR/Cas9.

1.Virus-like particles (VLPs) formed from the murine polyomavirus major capsid protein VP1 are widely used as vaccine antigens and are being explored as nucleic acid and drug delivery vehicles. However, the factors controlling distinct VP1 capsid morphologies remain unclear. We investigated in vitro VP1 assembly with tRNA across NaCl concentrations of 0.15-1.0 M and tRNA mass ratios of 1:1-1:80 (w/w) using SEC-HPLC, transmission electron microscopy, and dynamic light scattering. Two competing assembly pathways were identified. At low ionic strength ([&le;]0.15 M NaCl), nucleic acid-templated assembly produced compact, tRNA-filled T=1 VLPs ([~]28-30 nm). Assembly was maximal at tRNA ratios of 1:10-1:20, whereas excess or insufficient tRNA reduced yields. Increasing NaCl to 0.30 M lowered T=1 yields by 68-97%, and no T=1 particles were detected at [&ge;]0.5 M NaCl. Conversely, high ionic strength ([&ge;]0.5 M NaCl) promoted template-independent formation of hollow T=7 VLPs ([~]55-60 nm). T=7 assembly was inhibited by tRNA and was highest without nucleic acid. At 1.0 M NaCl, reducing the tRNA ratio from 1:40 to 1:80 increased T=7 yield more than 11-fold, while removing tRNA produced the greatest assembly efficiency. Kinetic analyses further showed that VP1 concentration and ionic strength regulate nucleation and assembly rate in the template-driven pathway. These findings show that electrostatic interactions govern pathway selection between tRNA-templated T=1 assembly and salt-driven T=7 self-assembly, providing practical guidance for controlling capsid morphology and cargo loading in VLP-based applications.

AbstractMetarhizium anisopliae is an important entomopathogenic fungi used in biological control of agricultural pests, but its commercial application is limited by relatively slow host mortality. This study aimed to engineer a chimeric protease (cPr1A) with enhanced binding affinity and protease activity against insect cuticle. We hypothesized that stronger cuticle binding would increase local enzyme concentration at the cuticle surface and thereby enhance cuticle degradation. To achieve this, the Bombyx mori chitin-binding domain (BmCBD) was fused to the C-terminus of the Pr1A protease from M. anisopliae. Recombinant Pr1A and cPr1A were expressed in Escherichia coli, purified by Ni-NTA affinity chromatography. Binding and protease activity were assayed in triplicate using Samia ricini cuticle powder as substrate. Results are presented as mean +/- SEM. The chimeric protease cPr1A showed a 28.9% increase in cuticle binding compared to wild-type Pr1A (15.81 +/- 1.97 vs. 12.27 +/- 2.13 g bound protein/mg cuticle powder; p < 0.002) and a 35% increase in protease activity (0.343 +/- 0.08 U/mg vs. 0.254 +/- 0.06 U/mg; p < 0.03). These results indicate that cPr1A is a promising candidate for overexpression in M. anisopliae to enhance cuticle degradation and potentially improve fungal virulence against insect pests.

Recombinant protein purification from E. coli frequently requires screening various affinity tags and variations to optimize yield and purity. However, classical cloning methods are limited in throughput and modularity, which is circumvented by GoldenGate cloning. While GreenGate cloning, a GoldenGate variant, is widely used in plant research, it lacks compatibility with E. coli expression vectors. Here, we introduce a comprehensive, GreenGate-compatible vector toolkit for efficient and versatile assembly of three modules, for N- and C-terminal tagging of a protein of interest into an IPTG-inducible E. coli expression vector. To allow versatility, this toolkit contains diverse affinity tags, with or without HRV3C protease cleavage sites. Moreover, we included plasmids for the homemade low-cost production of this protease. This GreenGate-compatible toolkit allows efficient combinations of different tags and eliminates the need for re-cloning modules between plant and bacterial systems, streamlining the workflow for recombinant protein production, especially in plant research.

Global demand for platform chemicals and biomaterials urges us to seek sustainable strategies along with waste valorization to produce lactic acid (LA) sustainably. The study has designed a one-pot fermentation strategy by employing in-house produced ligninolytic and saccharifying enzymes on rice straw along with a consortium of hexose and pentose sugar co-fermenting microorganisms. Biological pretreatment with in-house ligninolytic enzyme was selected for the one-pot strategy from a comparison study of chemical and enzymatic pretreatment of rice straw. In this study, simultaneous pretreatment and saccharification of rice straw followed by LA fermentation by Lactobacillus casei- Lactobacillus rhamnosus system (35.58{+/-}0.29 g/L) was found out to be more efficient than Lactobacillus casei-Lactobacillus pentosus system (29.80{+/-}0.92 g/L). Thus, the L. casei- L. rhamnosus system (CR system) was selected and was further statistically optimized by response surface methodology (RSM) to yield 64.96 g/L of LA. The fermentation broth was decolorized and purified by ion exchange chromatography to yield 85.56% pure LA with 84.95% optical purity. The one-pot fermentation strategy has reduced the number of unit operations involved to synthesize LA from rice straw without compromising the yield and purity through a greener route. The use of in-house enzymes and consortium of lactic acid producing bacteria in one-pot presents a strategic approach to sustainable LA production. The biological enroute and the minimum use of chemicals during upstream, fermentation, and downstream processing adds to the carbon credit of the process. HighlightsO_LILactic acid was produced from rice straw using one-pot co-fermentation strategy C_LIO_LIUpstream processing employed in-house enzymes from fungal solid-state fermentation C_LIO_LIThe process addresses the underutilization of pentose sugars after saccharification C_LIO_LIA consortium LAB produced 64.96 g/L LA with 0.855 g/L.h productivity C_LIO_LIDownstream processing yielded LA with 85.56% purity and 84.95% optical purity C_LI

Protein engineering and precision fermentation provide an opportunity to increase the value of food proteins by improving their solubility, stability, functionality, or nutritional composition. Here, we use {beta}-lactoglobulin ({beta}LG) as a model protein to investigate how state-of-the-art computational protein design approaches affect these properties. First, the deep learning-based design tool ProteinMPNN was used to alter up to 20% of {beta}LG residues for increased stability. Second, the physics-based modeling platform PyRosetta was used to find positions in {beta}LG accommodating increased branched-chain amino acid (BCAA) content and up to 10 residues were simultaneously exchanged. Experimental characterisation of ProteinMPNN and stabilised BCAA-enriched variants showed similar secondary structure and oligomeric state as native {beta}LG. ProteinMPNN variants gave increased titers and increased thermal stability up to 15 {degrees}C, and this correlated with changes in the rate of surface pressure in droplet tensiometry. Stabilized BCAA-enriched mutants had altered acid solubility. Correlations between computationally derived biophysical metrics and experimental properties are presented and suggest some predictive power for surface hydrophobicity on protein yield.

For structural-biology and protein-production pipelines, the hardest part of a difficult protein is not the biology -- it is obtaining a well-behaved sample for functional studies. Programs routinely stall at construct design, expression, and purification: deciding where to truncate, which tags to use, how to express, and how to purify so the protein survives concentration and handling. These decisions are still made largely by literature precedent and experimental experience, and they require trial-and-error before arriving at a functional construct for hard targets. We present a prospective, single-pair wet-lab case study testing whether an integrated computational platform can improve these decisions. For human fibroblast growth factor 21 (FGF21) -- a clinically important and stability-challenged metabolic hormone -- we compared two expression constructs produced side by side under the same experimental workflow, using two different design strategies: one designed by a scientist from the literature (reproducing the published core-domain construct, PDB 6M6E), and one designed by the Orbion platform -- an AI, prediction-guided protein-design system (orbion.life) -- which additionally generated the expression and purification protocols (executed scientist-in-the-loop). The platforms construct used an unconventional, longer C-terminal boundary not found in public sequence databases. Since the two constructs differ in more than one feature, we treat them as workflow-level designs throughout. The scientist construct gave a higher initial yield ([~]2.4 xmore protein recovered at affinity capture). The platform-designed construct, however, showed a more favourable downstream developability profile: it concentrated higher (1.4 vs 0.7 mg/mL) while remaining more monodisperse by dynamic light scattering (DLS). The scientist construct, in contrast, aggregated on concentration, so its initial-yield advantage did not survive: in the final concentrated sample the Orbion construct provided the more usable material for downstream studies. Computed for the mammalian host used, the platform had prospectively scored its own design higher (composite 68.7 vs 59.0 for the scientist-designed construct), and its predictions of yield, solubility, and disorder matched the wet-lab outcome. This is a single, deliberately scoped case study, not a population-level benchmark; the two constructs differ in more than one feature, and biological activity was not assayed. Alongside the bottlenecks of this approach discussed here, used as a decision aid, prediction-guided construct and protocol design has the potential to remove costly iteration cycles of protein production campaigns.

Background: The N-terminal ectodomain (NTE) of the SARS-CoV-2 membrane (M) glycoprotein is a short, flexible region that remains exposed on the virion surface and exhibits immunogenic potential across multiple coronaviruses. Despite its small size and conformational plasticity, this region contains conserved linear epitopes that may serve as practical surrogates for full-length proteins in serological diagnostics. Objective: To develop and evaluate a synthetic peptide-based diagnostic assay targeting the NTE of the SARS-CoV-2 M protein. Methods: Epitope prediction, peptide synthesis, and antibody affinity assays were performed to design homomultivalent peptide analogs that exploit avidity effects through disulfide polymerization. The resulting peptide antigens were tested in an enzyme-linked immunosorbent assay (ELISA) using clinical samples from RT-PCR-confirmed COVID-19 patients and biobanked controls. Results: The selected peptide analogs (M1, M1i, M1s) corresponded to a conserved surface-exposed motif of the SARS-CoV-2 M protein. Polymeric M1 exhibited a twofold gain in apparent affinity (Kdapp = 4.33 nM) compared with the monomeric form (Kdapp = 8.00 nM). Clinical validation using 1,222 patient samples yielded a sensitivity of 95.26% and specificity of 52.27%, with an overall diagnostic accuracy of 88.70%. Conclusion: The M peptide analogs demonstrate that synthetic peptide antigens can serve as stable, high-sensitivity surrogates for whole-protein assays. This design principle may be applied to other emerging pathogens where rapid assay development and scalability are critical. Keywords: Peptides, Antibodies, COVID-19, Enzyme-Linked Immunosorbent Assay, Protein Binding

Calreticulin is an emerging cancer biomarker, but current detection methods rely on expensive monoclonal antibodies that suffer from inefficient protein production, pharmacokinetic challenges and poor tissue penetration. Cal3, a calreticulin-specific nanobody, was constructed by replacing the complimentary determining region 2 (CDR2) of a soluble, clinically validated nanobody with a calreticulin-specific CDR2 isolated from a phage display library. However, the poor solubility and low yield of Cal3 limit its usefulness. In this study, we engineered CALR-Nb02 by adapting the core of Cal3 to a partial consensus framework sequence of stable nanobodies. CALR-Nb02 was purified with a 240-fold higher yield as a predominantly monomeric, soluble protein that exhibits an increased thermal stability and a higher calreticulin binding affinity (KD: 25-50 nM) compared with Cal3. These results reveal a strategy for quickly altering the specificity of a stable nanobody, and provide an improved calreticulin-binding reagent for future diagnostic, imaging, and therapeutic applications.

The development of cost-effective, serum-free media is critical for scalable cultivated meat production. This study used high-throughput screening through a Design of Experiments (DoE) approach to develop an animal-free, serum-free medium (MMM1) specifically for the C2C12 murine myoblasts model cell line with applicability in cultivated meat research including for pet food. Low cost, food-grade inputs such as methylcellulose and spirulina extract resulted in significant cell growth improvements. The optimised MMM1 formulation containing low cost, food-grade inputs, achieved cumulative population doublings comparable to 10% (v/v) fetal bovine serum over four consecutive passages. Furthermore, MMM1 supported scalable cell expansion on commercially available dextran-based microcarriers (Cytodex-3) in both static and agitated conditions in spinner flasks, matching growth rates of serum-based controls. Finally, transitioning to a food-grade DMEM/F12 basal medium maintained cell proliferation equivalent to the pharmaceutical-grade DMEM/F12, but at a significantly lower cost, thus offering a viable strategy to substantially reduce biomanufacturing costs which is a critical challenge in cultivated meat production.

With the rapid development of modern biotechnology, DNA vectors have become fundamental tools for inserting, transferring, and expressing specific gene sequences in various fields such as gene cloning, gene expression, gene editing, and gene therapy. However, when dealing with complex structured DNA sequences, traditional vector construction methods face challenges with low connection efficiency. This study proposes a new method for constructing recombinant vectors by employing a strategy of high-temperature treatment followed immediately by placement on ice, effectively reducing the complexity of DNA structures and enhancing the efficiency of PCR product-vector connection, thereby improving the construction efficiency of recombinant vectors. This paper describes the technical details of the method, experimental validation, and applications in gene cloning, gene recombination editing, and the preparation of gene therapy drugs, providing a new efficient tool for molecular biology experiments.