Search Results (122)

In this study, a previously uncharacterized zearalenone lactone hydrolase, ZHD30L, from Knufia peltigerae was identified and characterized, and semi-rational design was employed to enhance its thermostability. The results indicate that the optimal reaction conditions for this enzyme are 40 °C and pH 9.0, under which it catalyzes the ring-opening of the ZEN lactone to generate the non-toxic product HZEN. The mutant with five combined sites Mut5, (E11T-A127V-I180K-H235P-V156I), was obtained through semi-rational design combined with multiple rounds of iterative superposition and negative elimination strategies. Thermodynamic characterization revealed that, compared to the wild type, the t_1/2 of Mut5 at 48 °C was significantly extended from 1.67 min to 796.8 min, and the T_m value increased from 39.56 °C to 50.04 °C. The markedly prolonged thermal half-life and increased apparent melting temperature may improve the operational robustness of Mut5 during moderate-temperature feed and food processing or post-processing applications, potentially reducing activity loss and the need for repeated enzyme additions. Concurrently, the k_cat/K_M improved from 19.08 μM⁻¹·s⁻¹ (95% Cl = 12.80 to 25.36 μM⁻¹·s⁻¹) to 33.29 μM⁻¹·s⁻¹ (95% Cl = 23.20 to 43.38 μM⁻¹·s⁻¹). Under optimal reaction conditions, WT and Mut5 degraded 76.51% ± 1.65% and 99.13% ± 0.71% of ZEN (10 μg/mL), respectively, within 3 min at equal enzyme concentrations. Molecular dynamics simulations indicate that the H235P and E11T mutations reduce local conformational entropy, the A127V and V156I mutations optimize internal hydrophobic stacking, and the I180K mutation reshapes the local charge microenvironment. Furthermore, Mut5 exhibited an overall RMSD at high temperatures that was 0.026 Å lower than that of the wild type, and a global free energy minimum that was 0.36 kcal/mol lower. These computational results offer possible structural interpretations, providing a theoretical reference for developing highly efficient enzyme preparations for the feed and food industries. Full article

Helicobacter pylori possesses an unusually high number of restriction–modification (R-M) systems relative to its small genome, contributing to a methylome increasingly implicated in bacterial gene regulation. In this study, we analyzed the methylomes of two mutant strains of H. pylori 26695: ∆rdxA (control) and ∆rdxA/∆arsS. Each mutant was cultivated under neutral (pH 7) and acidic (pH 5) growth conditions. We identified one conspicuous hypomethylated region of 21 kBp possessing 21 annotated genes across each methylome. Notably, over 600 protein coding regions and 10 different promoters displayed differential methylation between pH conditions, including several virulence factors. The vacA gene, encoding the Vacuolating Cytotoxin A, exhibited eight differentially methylated positions between pH 7 and pH 5 within the H. pylori 26695 control mutant methylome, potentially contributing to its previously documented 32-fold down regulation of mRNA in acidic environments. pH-dependent methylation changes were widespread within the cag pathogenicity island, genes encoding cell envelope proteins including adhesin-encoding sabA, babA, and hopQ, and numerous flagellar-associated genes. These results reveal the plasticity of the H. pylori methylome and suggest that DNA methylation is responsive to environmental pH in both ArsRS-dependent and independent manners. Methylome dynamics may serve as an important layer of gene regulation in acclimation to hostile gastric environments and promote persistent infection. Full article

Diffuse midline glioma (DMG) is one of the most aggressive paediatric brain tumours and remains almost universally fatal despite decades of research. The defining molecular feature of approximately 80% of DMG tumours is H3K27M, which disrupts PRC2 activity and profoundly remodels chromatin architecture. Increasing evidence suggests that this epigenetic alteration not only rewires transcriptional programs but also influences tumour metabolism. Several studies indicate that H3K27M-mutant tumours exhibit altered mitochondrial metabolism, oxidative phosphorylation activity, redox regulation, and cellular stress responses, although the extent of oxidative phosphorylation dependence varies between models, tumour subtypes, and cellular states. In parallel, dopaminergic signalling has been implicated in cancer stem cell maintenance, metabolic regulation, and tumour survival across multiple malignancies, including glioma. The imipridone compound ONC201/dordaviprone, initially described as a dopamine receptor D2/3 antagonist and subsequently characterised as a mitochondrial ClpP agonist, demonstrates clinical activity in H3K27M-mutant DMG and induces mitochondrial stress responses. In this review, we examine emerging connections between epigenetic dysregulation, mitochondrial metabolism, and dopamine signalling in DMG. We propose that H3K27M-driven epigenetic reprogramming may impose metabolic constraints that increase tumour reliance on mitochondrial bioenergetics and stress-buffering pathways. Within this context, dopamine signalling may function as a metabolic rheostat that contributes to mitochondrial homeostasis; however, this remains a hypothesis requiring direct experimental validation in DMG models. Pharmacologic disruption of this axis may destabilise tumour metabolism and expose therapeutically exploitable vulnerabilities in this otherwise treatment-resistant disease. Full article

African swine fever (ASF) is an acute, febrile, and lethal pig disease induced by the African swine fever virus (ASFV). In the absence of an effective vaccine, early diagnosis is essential for the prevention and control of ASF disease. The p54 protein is important for ASFV diagnosis and vaccine design. In this study, ASFV p54 protein was constructed, expressed, purified, and used to generate three mAbs, namely 9A3, 5H2, and 2G6. Epitope mapping was performed using alanine mutants; the minimal linear epitope recognized by 9A3 and 5H2 was ⁵⁶KKKAAAI⁶², and the minimal linear epitope recognized by 2G6 was ¹⁰⁸TNRPATN¹¹⁴. Of these, ⁵⁶KKKAAAI⁶² was identified as a new linear epitope for the first time. The epitopes were highly conserved in at least genotypes I and II. Alanine-scanning mutagenesis further revealed that residues 56K, 57K, 60A, 61A, 62L, 108T, 110R, 111P, 113T, and 114N were the core sites involved in antibody recognition. Overall, the mAbs and epitopes of the p54 protein identified in this study provide theoretical support for the development of ASFV vaccines based on the B cell epitope, the development of ASFV therapeutic antibody drugs, and the development of ASFV diagnostic tools. Full article

Thermophilic prokaryotic Argonaute proteins (pAgos) have emerged as powerful tools for nucleic acid manipulation, with applications in nucleic acid detection, and DNA assembly. However, their strong dependence on high-temperature catalytic activity limits their utility under moderate conditions. TcAgo, a thermophilic Argonaute nuclease from Thermogladius calderae, exhibits efficient DNA-guided target DNA cleavage above 80 °C, yet its structural basis and catalytic mechanism remain unclear. In this study, we attempted to analyze the structure of the TcAgo ternary complex and performed rational engineering based on its structure and characteristics of cold-adapted enzymes. A mutant, mTcAgo (K574G, D577G), was obtained with enhanced activity at moderate temperatures. Compared with the wild type, mTcAgo exhibited significantly improved cleavage activity toward both DNA and RNA targets at 37 °C. It utilized multiple guide types, including 5′OH- and 5′P-modified DNA and RNA guides, with a preference for 5′P-gDNA. mTcAgo displayed optimal activity at pH 7–8, broad salt tolerance, and an extended catalytic temperature range from 37 °C to 95 °C. Notably, it retained high activity after incubation at 90 °C, with a melting temperature of ~88 °C, and efficiently cleaved GC-rich targets under low Mg²⁺ conditions. These results demonstrate that rational cold-adaptation engineering can expand the functional temperature range of thermophilic pAgos, providing a promising strategy for developing versatile nucleic acid tools. Full article

Endophytic fungi are promising sources of novel antiviral compounds, and the crude extract from Alternaria alternata PO4PR2 has previously shown anti-HIV-1 activity. This study evaluated its efficacy against integrase strand-transfer inhibitor (INSTI)-resistant HIV-1 and its mechanism of action. Key resistance mutations (Y143H, G118R, N155H, and R263K) were introduced into the HIV-1 pNL4.3 clone via site-directed mutagenesis and confirmed through Sanger sequencing. Viral infectivity was assessed in TZM-bl cells, while cytotoxicity was measured using an MTT assay. Antiviral activity was determined through a luciferase-based assay, and integration inhibition was evaluated using integrase activity assays and Alu-gag nested PCR. The extract demonstrated potent inhibition of resistant mutants, with low IC₅₀ values (0.02971–0.1652 μg/mL), and showed minimal cytotoxicity (CC₅₀ = 300 μg/mL), maintaining over 80% cell viability. It inhibited integrase activity by 67%, specifically targeting the strand-transfer step, and significantly reduced integrated viral DNA. Molecular docking of 14 compounds identified coumarin derivatives as key bioactive metabolites, exhibiting mutation-tolerant binding within the integrase catalytic pocket. Overall, these findings highlight PO4PR2 as a promising source of compounds for developing new therapies targeting drug-resistant HIV-1 integrase. Full article

This study addressed the issue of insufficient activity in CALB lipase during the catalytic synthesis of key chiral intermediates for moxifloxacin. A structure-guided protein engineering strategy was employed to systematically modify its functional domains. Through molecular dynamics simulations of CALB-I189K, multiple regions exhibiting high conformational flexibility were preliminarily identified. Subsequently, by integrating 3D structural alignment with active site pocket distance analysis, the functionally most critical region (143–146) was selected. A site-directed saturation mutation library was constructed specifically targeting this region. Building upon the previously reported CALB-I189K, a mutant I189K/L144R/A146K was ultimately obtained through high-throughput screening combined with chiral HPLC validation. This mutant maintains excellent stereoselectivity (E = 206.52) while enhancing catalytic efficiency (k_cat/Κ_m) to 273.73 min⁻¹·mM⁻¹, approximately 4.5-fold that of I189K. At a substrate concentration of 1 M, it achieves 50% conversion within 2.6 h, demonstrating kinetic resolution capabilities approaching industrial standards. Molecular simulation analysis indicates that the L144R and A146K mutations synergistically enhance catalytic performance primarily by optimizing spatial distances between catalytic residues. This study not only provides a high-performance catalyst for the efficient biosynthesis of moxifloxacin chiral intermediates but also offers new insights for enzyme rational design based on dynamic structural information. Full article

Diffuse midline gliomas (DMGs) are rare but highly aggressive central nervous system (CNS) tumors that can present in both pediatric and adult populations. These tumors were redefined in the 2016 WHO classification of CNS tumors based on integrated histopathological and molecular features, and were initially designated as “DMG, H3 K27M-mutant”. In the 2021 WHO update, DMGs were incorporated into the newly defined category of primarily pediatric-type diffuse high-grade gliomas, and nomenclature was changed to “DMG, H3 K27-altered” to encompass additional molecular drivers beyond the canonical H3 K27M mutation. Clinically, DMGs arise as expansile, infiltrating tumors within midline structures and may present as non-enhancing or enhancing lesions on imaging. Diagnosis is based on neuroimaging and molecular confirmation by immunohistochemistry or sequencing when tissue is available. DMGs are categorized as WHO grade 4 malignant tumors due to their aggressive biology leading to rapid and infiltrative growth. Owing to their deep and midline location, surgical resection is typically not feasible. Radiation therapy is the backbone of treatment, but there is no standard regimen of chemotherapy that has demonstrated durable efficacy. Recent progress in therapeutic approaches has led to a major breakthrough on 6 August 2025 when the U.S. Food and Drug Administration granted the accelerated approval of dordaviprone (ONC201), marking it as the first systemic therapy for progressive DMG harboring H3 K27M mutation. Other novel approaches, including chimeric antigen receptor (CAR) T-cell directed therapies and convection-enhanced delivery, are actively under investigation. We aim to comprehensively review DMGs, including the recent insights into their biology, the evolving therapeutic landscape, and the opportunities to fuel this new momentum against one of the most formidable gliomas. Full article

Aflatoxin B1 (AFB1) poses a serious threat to global food and feed safety. Laccase-based enzymatic degradation represents a promising green strategy for AFB1 removal; however, its industrial application is severely limited by the rapid thermal inactivation of wild-type enzymes under high-temperature processing conditions (>70 °C). Here, we engineered the thermal stability of a laccase from Bacillus amyloliquefaciens B10 through an integrated strategy combining computational structural biology with semi-rational design. By coupling molecular dynamics (MD) simulations with folding free-energy (ΔΔG) calculations, we identified key flexible regions associated with thermal instability and subsequently implemented iterative saturation mutagenesis. The best single mutant, R196C, retained more than 96% relative activity after heat treatment at 80 °C for 10 min. Further iterative mutational stacking progressively enhanced thermostability: the R90E/R196C double mutant showed 1.25-fold higher activity at 80 °C than R196C, and the R90E/R196C/H54F triple mutant showed a further 1.16-fold increase over the double mutant. The final quadruple mutant, R90E/R196C/H54F/R253I, achieved 86.9% AFB1 degradation at 80 °C after 24 h. High-temperature MD simulations (100 ns at 353.15 K) indicated that the enhanced thermostability was associated with reduced conformational flexibility, lower radius of gyration (Rg) and solvent-accessible surface area (SASA), and a coil-to-β-sheet transition that contributed to stabilization of the protein core. In addition, efficient secretory expression of the engineered enzyme was achieved in Pichia pastoris, reaching 3.0 U/mL, while the crude enzyme maintained more than 70% activity at 80 °C. Collectively, these results provide a practical basis for the rational engineering and scalable production of thermostable biocatalysts for AFB1 detoxification-related applications of AFB1 control, and offer broader insights into the targeted enhancement of thermal stability in industrial enzymes. Full article

Background: Rabies is a highly fatal zoonotic disease that causes approximately 59,000 human deaths worldwide each year. Current inactivated rabies vaccines require multiple doses and are associated with high costs. The full-length rabies virus glycoprotein (RVG), a membrane protein, exhibits substantial instability in its trimeric structure during recombinant expression. This instability makes it difficult to obtain high-purity, correctly folded antigens. Objectives: This study focuses on the preparation of a full-length recombinant RVG subunit vaccine candidate expressed in a glycoengineered Pichia pastoris system with mammalian-like glycosylation. Methods: The full-length RVG gene (including the transmembrane domain and cytoplasmic tail) from the Challenge Virus Standard-11 (CVS-11) strain was codon-optimized and inserted into the pPICZαA vector to construct the recombinant expression plasmid pPICZαA-RVG. The plasmid was transformed into glycoengineered Pichia pastoris X33-7 (low-mannose type) by electroporation for inducible expression. The target protein was purified by nickel affinity chromatography, anion-exchange chromatography, and Superdex-200 size-exclusion chromatography. The structural characteristics of the purified protein were analyzed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The purified antigen was formulated with the adjuvants AS03 or MF59. BALB/c mice (n = 5 per group) were immunized intramuscularly following a four-dose schedule (days 0, 7, 14, and 28). Antigen-specific IgG antibody titers were measured by ELISA, and neutralizing antibody titers were determined using the rapid fluorescent focus inhibition test (RFFIT). Results: Glycoengineered Pichia pastoris yeast strains expressing wild-type RVG (RVG-WT) or a mutant variant (RVG-M6: R84S, R199S, H270P, R279S, K300S, and R463S) were successfully constructed. The purified RVG antigen formed nanoparticles with an average particle size of approximately 75 nm. Immunized mice generated robust RVG-specific IgG responses, with titers reaching approximately 6.31 × 10⁵ for RVG-WT after the fourth immunization, compared to 3.16 × 10³ for RVG-M6 and 5.62 × 10³ for the RVG-WT-PEG control. Two weeks after the fourth immunization, RVG-WT formulated with AS03 or MF59 induced significant neutralizing antibody responses compared with the control group (p < 0.0001 and p < 0.01, respectively). The neutralizing antibody titers reached 1:79.43 in the AS03 group and 1:33.11 in the MF59 group, whereas the WT-PEG + AS03 control group showed a low titer of 1:3.72. In contrast, RVG-M6 formulated with MF59 failed to induce detectable neutralizing antibodies (1:3.02). Furthermore, RVG-WT + AS03 induced significantly higher neutralizing antibody responses than the WT-PEG + AS03 control group (p < 0.0001), and a significant difference was also observed between the RVG-WT + MF59 and RVG-M6 + MF59 groups (p < 0.01). Conclusions: The glycoengineered Pichia pastoris expression system successfully produced uniform full-length rabies virus glycoprotein nanoparticles with high purity. When formulated with the AS03 adjuvant, RVG-WT induced high-titer neutralizing antibodies in mice, suggesting a promising strategy for the development of recombinant subunit vaccines against rabies. However, this study is limited by the absence of challenge studies and validation in target animal species, which will be further investigated in future work. Full article

Background/Objectives: Diffuse midline glioma (DMG), H3 K27M-altered, represents a rare group of gliomas arising in midline structures of the central nervous system. Historically regarded as a pediatric entity, it is now increasingly recognized in adults. Although its relative prevalence among all midline diffuse gliomas and its clinical-radiological characteristics are well defined in children, these tumors remain less characterized in adults, and comparative evaluations with H3 K27 wildtype midline diffuse gliomas are limited. Methods: Consecutive adult patients with histopathologically confirmed diffuse glioma (WHO grade ≥ 2) diagnosed between 2016 and 2025 were retrospectively screened for midline tumor location, with systematic revision of imaging and pathology. For identified midline diffuse gliomas, comprehensive clinical, imaging, and immunohistochemical data were collected, and a detailed morphometric analysis was performed. H3 K27 alteration status was established immunohistochemically, with supplementary immunostaining when necessary. Descriptive and comparative analyses were conducted. Results: A total of 5% of the 541 adult diffuse gliomas were midline, and 23% of IDH wildtype midline gliomas were consistent with DMG, H3 K27-altered (all H3 K27M-mutant). The affected patients were significantly younger, and these tumors predominantly involved the thalamus and mesencephalon. Morphometric analyses revealed trends toward fewer high-grade features in H3 K27-altered tumors, with composite scores demonstrating significant discriminatory ability. The overall survival was not significantly different between groups but showed associations with ring-like enhancement as well as adjuvant and salvage therapies in the overall midline cohort. Conclusions: This study provides population-based prevalence estimates for DMG, H3 K27M-altered, and complements the limited literature with comparative clinical-radiological and morphometric data of potential prognostic relevance. Full article

Plants respond to ultraviolet B radiation (280–320 nm) with an integrated reaction that includes the reception of the acting stress factor, followed by the generation of reactive oxygen species and damage to macromolecules and membrane structures, as well as changes in cellular metabolism and the formation of protective systems. However, the involvement of key UV-B–related signalling components such as HY5, SPA1 and BIC1 or BIC2 proteins in physiological, biochemical and molecular responses remains insufficiently understood. The effects of 8, 16 and 24 h of UV-B exposure (within an 8 h photoperiod over three days) on the net photosynthetic rate (Pn), chlorophyll fluorescence parameters Y(II) and F_v/F_m, reflecting the functional state of PSII, nonphotochemical quenching (NPQ), pigment contents (Chl(a+b), carotenoids, anthocyanins and UV-absorbing pigments (UAPs) and the expression of key light-induced genes in wild-type Arabidopsis thaliana and spa1, bic1,2 and hy5 mutants were studied. UV-B irradiation resulted in a gradual reduction in the Pn, Y(II), F_v/F_m values and Chl(a+b) but caused a marked increase in the anthocyanin and UAP contents and only minor changes in the carotenoid content. The hy5 mutant presented the lowest net photosynthetic rate (Pn), chlorophyll fluorescence parameters, and chlorophyll and carotenoid contents under all the UV-B exposures. In addition, the accumulation of anthocyanins and UAPs during UV-B treatment was consistently the lowest in hy5. After any UV-B exposure, the highest accumulation of UAPs and anthocyanins was observed in the spa1 mutant, whereas the highest Pn values were detected after 24 h in bic1,2. One of the reasons for the reduced photosynthetic activity and antioxidant capacity in hy5 may be the lower expression levels of CHS and PAL in this variety than in the other genotypes. Our results indicate that HY5 is required to maintain antioxidant responses and photosynthetic performance under repeated daytime UV-B exposure (16.8 kJ m⁻² per day). In contrast, BIC1, BIC2, and SPA1 also contribute to UV-B tolerance, but through distinct regulatory mechanisms and to a lesser extent. Full article

Background/Objectives: SETD2 is a dual-function methyltransferase important for methylation of histone H3 at lysine 36 and α-tubulin in spindle microtubules. Genetic inactivation of SETD2 during oncogenesis drives loss of H3K36me3, genomic instability, and cancer progression. This study asked if disruption of genomic stability was a canonical feature of SETD2 inactivation via different pathways. Methods: We evaluated the impact of EPZ-719, a pharmacologic SETD2 inhibitor, and an H3.3K36M mutant histone (“oncohistone”) that binds and sequesters SETD2, on methylation activity and genomic stability in human cell lines. SETD2 activity was measured using in vitro methylation assays, H3K36me3 loss confirmed by Western analysis, and mitotic defects, specifically micronuclei and chromatin bridges, quantified with cytogenetic analysis. Results: EPZ-719 caused a dose- and time-dependent reduction in SETD2 activity on both histone and tubulin substrates, accompanied by significant increases in chromatin bridges and micronuclei in retinal pigmented epithelial (RPE-1) and 786-O ccRCC cells. Similarly, oncohistone expression markedly decreased SETD2 function, as determined by H3K36me3 levels, and induced comparable mitotic defects in 786-O cells, and aneuploidy in two chondrocyte cell lines expressing the H3.3K36M oncohistone. Combining EPZ-719 with H3.3K36M expression did not exacerbate mitotic defects beyond either oncohistone or pharmacologic inhibition alone, consistent with inhibition of SETD2 as their shared underlying mechanism of action. Conclusions: Pharmacologic inhibition and oncohistone-mediated sequestration of SETD2 converge on the induction of mitotic defects, underscoring SETD2’s essential role in maintaining genomic stability. Identification of loss of genomic stability as a canonical feature of SETD2 inactivation points to a potential therapeutic liability associated with targeting SETD2 in cancers where it is overexpressed and reveals a mechanism that could contribute to the progression of cancers expressing oncohistone mutations. Full article

Fructooligosaccharides (FOSs) are plant-based prebiotics widely utilized in the food and pharmaceutical industries. As a major sugar-producing region, Guangxi holds significant potential for enzymatic production of FOS from sucrose. This study engineered a mutant enzyme, 142P-242K, to address the low catalytic activity characteristic of wild-type enzymes. The mutation upregulated the FOS conversion efficiency from 29 to 52%, respectively. Optimal enzymatic activity was observed at 45 °C, pH 6.0, and in the presence of 1 mM Na⁺. Mechanistic investigations revealed that modifications to the catalytic domain pocket and shifts in substrate affinity were the primary factors driving enhanced FOS production. The accumulation of 1-Kestose (GF2) was attributed to the enhanced flexibility of the 142P-242K loop, which facilitates substrate access to the active site. However, the synthesis of nystose (GF3) from GF2 is hindered by the hydrophobic nature of the active site and strong hydrogen bonds binding GF2. Comparing the enzyme’s ability to produce FOS using sugarcane juice, sugarcane molasses, and adsorption-heating sugarcane molasses, it was determined that heat-adsorbed molasses yielded the highest FOS concentration (30.77%). This study offers a practical and cost-effective strategy for enzyme modification and efficient valorization of molasses. Full article

This study aims to construct a nattokinase (NK) high-yielding strain using the multiple-scale breeding method. First, an NK-producing strain Bacillus subtilis A-1 was isolated from fermented soybean, which produces 254 FU/mL of NK. Subsequently, ARTP mutagenesis was employed to screen high-yield mutants with resistance to rifampicin (i.e., strain R-F7), kanamycin (i.e., strain K-E11), and gentamicin (i.e., strain G-D5), and the resulted strains showed NK activity increases of 113.78%, 76.38%, and 62.99%, respectively. Moreover, a fusion strain C-D7 with resistant to the above three antibiotics (i.e., rifampicin, kanamycin, and gentamicin) was obtained by protoplast fusion, which produced 610 FU/mL of NK and represents a 140.16% higher that of strain A-1. The fermenting property of strain C-D7 was also done in a 5-L bioreactor, and results indicated that strain C-D7 produced 1020 ± 35 FU/mL of NK under a two-stage pH control strategy and a two-step feeding strategy. To elucidate the genetic basis for the high-yield phenotype of C-D7. comparative whole-genome analysis was performed between C-D7 and the parental strain A-1. The results revealed that C-D7 harbors specific mutations across multiple functional categories, primarily in genes related to transcription, translation, global regulation, as well as metabolism and secretion. The biological processes affected by these mutations show a strong correlation with the high-yield trait, suggesting their potential collective role in contributing to the observed increase in nattokinase production. Lastly, ituD and srfAC were knocked out to reduce foam during fermentation, thus reducing the use of antifoaming agents and mitigating the negative effects on cell growth. In a word, a genetically stable, high-yield, and low-foaming Bacillus subtilis strain C-D7-ΔDouble was constructed in this study, which provides a core microbial resource and process foundation for the low-cost industrial production of nattokinase. Full article