Engineering substrate specificity of quinone-dependent dehydrogenases for efficient oxidation of deoxynivalenol to 3-keto-deoxynivalenol.

The oxidative reaction of Fusarium mycotoxin deoxynivalenol (DON) using the dehydrogenase is a desirable strategy and environmentally friendly to mitigate its toxicity. However, a critical issue for these dehydrogenases shows widespread substrate promiscuity. In this study, we conducted pocket reshaping of Devosia strain A6-243 pyrroloquinoline quinone (PQQ)-dependent dehydrogenase (DADH) on the basis of protein structure and kinetic analysis of substrate libraries to improve preference for particular substrate DON (10a). The variant presented an increased preference for substrate 10a and enhanced catalytic efficiency. A 4.7-fold increase in preference for substrate 10a was observed. Kinetic profiling and molecular dynamics (MD) simulations provided insights into the enhanced substrate specificity and activity. Moreover, the variant exhibited stronger conversion of substrate 10a to 3-keto-DON compared to the wild DADH. Overall, this study provides a feasible protocol for the redesign of PQQ-dependent dehydrogenases with favourable substrate specificity and catalytic activity, which is desperately needed for DON antidote development.

Fermentation of millet bran with Bacillus natto: enhancement of bioactivity levels and the bioactivity of bran extract.

BACKGROUND: Millet bran (MB), a byproduct of millet production, is rich in functional components but it is underutilized. In recent years, researchers have shown that fermentation can improve the biological activity of cereals and their byproducts. This study used Bacillus natto to ferment millet bran to improve its added value and broaden the application of MB. The bioactive component content, physicochemical properties, and functional activity of millet bran extract (MBE) from fermented millet bran were determined. RESULTS: After fermentation, the soluble dietary fiber (SDF) content increased by 92.0%, the ß-glucan content by 164.4%, the polypeptide content by 111.4%, the polyphenol content by 32.5%, the flavone content by 16.4%, and the total amino acid content by 95.4%. Scanning electron microscopy revealed that the microscopic morphology of MBE changed from complete and dense blocks to loosely porous shapes after fermentation. After fermentation, the solubility, water-holding capacity, and viscosity significantly increased and the particle size decreased. Moreover, the glucose adsorption capacity (2.1 mmol g-1), glucose dialysis retardation index (75.3%), and α-glucosidase inhibitory (71.4%, mixed reversible inhibition) activity of the fermented MBE (FMBE) were greater than those of the unfermented MBE (0.99 mmol g-1, 32.1%, and 35.1%, respectively). The FMBE presented better cholesterol and sodium cholate (SC) adsorption properties and the adsorption was considered inhomogeneous surface adsorption. CONCLUSION: Fermentation increased the bioactive component content and improved the physicochemical properties of MBE, thereby improving its hypoglycemic and hypolipidemic properties. This study not only resolves the problem of millet bran waste but also encourages the development of higher value-added application methods for millet bran. © 2024 Society of Chemical Industry.

Engineering a Lactobacillus Lysine Riboswitch to Dynamically Control Metabolic Pathways for Lysine Production in Corynebacterium glutamicum.

Knock-out of genes of metabolic pathways is conventionally used in the metabolic engineering of microorganisms, but it is not applicable for genes of essential pathways. In order to avoid undesirable effects caused by gene deletion, it is attractive to develop riboswitches to dynamically control the metabolic pathways of microbial cell factories. In this regard, the aim of this study is to utilize the lysine riboswitch to control gene expressions of the biosynthetic pathways and by-pathways and thus improve lysine production in Corynebacterium glutamicum. To achieve this, a natural lysine riboswitch from Lactobacillus plantarum (LPRS) was first detected and then fused with RFP to test its functionality. After that, engineered lysine-activated (Lys-A) and lysine-repressed (Lys-R) riboswitches were successfully screened by dual genetic selection. Furthermore, the optimized A263 and R152 were applied to control the expression of aspartate kinase III and homoserine dehydrogenase in the lysine-producing strain C. glutamicum QW45, respectively. In contrast with QW45, the growth of the resulting A263-lysC mutant QW48 was similar to that of QW45; however, the growth of the resulting R357-hom mutant QW54 was slightly inhibited, indicating an inhibition of threonine biosynthesis caused by the riboswitch upon binding of intracellular lysine. Importantly, the lysine production of QW48 and QW54 was, respectively, 35% and 43% higher than that of the parent strain QW45, implying more metabolic flux directed into the lysine synthesis pathway. Finally, the engineered A263 and R357 were simultaneously applied to the same mutant QW55, which greatly improved lysine production. Thus, the approach demonstrated in this work could be principally used as a powerful tool to dynamically control any other undesired metabolic pathways.

Drug-loaded lipid nanoparticles improve the removal rates of the Staphylococcus aureus biofilm.

Biofilms of the foodborne pathogen Staphylococcus aureus show improved resistance to antibiotics and are difficult to eliminate. To enhance antibacteria and biofilm dispersion via extracellular matrix diffusion, a new lipid nanoparticle was prepared, which employed a mixture of phospholipids and a 0.8% surfactin shell. In the lipid nanoparticle, 31.56 µg mL-1 of erythromycin was encapsulated. The lipid nanoparticle size was approximately 52 nm and the zeta-potential was -67 mV, which was measured using a Marvin laser particle size analyzer. In addition, lipid nanoparticles significantly dispersed the biofilms of S. aureus W1, CICC22942, and CICC 10788 on the surface of stainless steel, reducing the total viable count of bacteria in the biofilms by 103 CFU mL-1 . In addition, the lipid nanoparticle can remove polysaccharides and protein components from the biofilm matrix. The results of laser confocal microscopy showed that the lipid nanoparticles effectively killed residual bacteria in the biofilms. Thus, to thoroughly eliminate biofilms on material surfaces in food factories to avoid repeated contamination, drug-lipid nanoparticles present a suitable method to achieve this.

Prevention of high-fat-diet-induced obesity in mice by soluble dietary fiber from fermented and unfermented millet bran.

Obesity-related diabetes, cardiovascular disease, and hypertension pose many risks to human health. Thus, mice on a high-fat diet were gavaged with millet bran (unfermented/fermented) soluble dietary fiber (RSDF/FSDF, 500 mg·kg-1) for 10 weeks in current research, and then evaluated the various biological indicators. These findings revealed that RSDF and FSDF supplements could prevent fat synthesis by inhibiting sterol regulatory element-binding protein-1c gene expression. The RSDF supplements can also accelerate fat catabolism through enhanced the mRNA expression levels of adipose triglyceride lipase and peroxisome proliferator-activated receptor α. FSDF supplements can prevent obesity by decreasing 3-hydroxy-3-methyl-glutaryl-CoA reductase expression and increasing cholesterol 7α-hydroxylase expression. Moreover, FSDF also controls obesity development by lowering total cholesterol and low-density lipoprotein cholesterol levels in the blood, triglyceride, total cholesterol, and bile acid levels in the liver. Notably, FSDF supplements can promote Bacteroides and Prevotella propagation; excretive propionic acid binds to free fatty acid receptor 2/3 and then stimulates intestinal epithelial cells to generate glucagon-like-peptide-1 and peptide YY, which can reduce food and energy intake and ultimately prevent obesity. All evidence suggests that FSDF supplements play a crucial role in preventing obesity.

Self-cascade deoxynivalenol detoxification by an artificial enzyme with bifunctions of dehydrogenase and aldo/keto reductase from genome mining.

Due to the severe health risks for human and animal caused by the intake of toxic deoxynivalenol (DON) derived from Fusarium species, elimination DON in food and feed has been initiated as a critical issue. Enzymatic cascade catalysis by dehydrogenase and aldo-keto reductase represents a fascinating strategy for DON detoxification. Here, one quinone-dpendent alcohol dehydrogenase DADH oxidized DON into less-toxic 3-keto-DON and NADPH-dependent aldo-keto reductase AKR13B3 reduced 3-keto-DON into relatively non-toxic 3-epi-DON were identified from Devosia strain A6-243, indicating that degradation of DON on C3 are two-step sequential cascade processes. To establish the bifunctions, fusion enzyme linking DADH and AKR13B3 was successfully assembled to promote one-step DON degradations with accelerated specific activity and efficiency, resulting 93.29 % of DON removal rate in wheat sample. Three-dimensional simulation analysis revealed that the bifunctional enzyme forms an artificial intramolecular channel to minimize the distance of intermediate from DADH to AKR13B3 for two-step enzymatic reactions, and thereby accelerates this enzymatic process. As the first report of directing single step DON detoxification by an interesting bifunctional artificial enzyme, this work revealed a facile and eco-friendly approach to detoxify DON with application potential and gave valuable insights into execute other mycotoxin detoxification for ensuring food safety.

Rational engineering and insight for a L-glutaminase activity reduced type II L-asparaginase from Bacillus licheniformis and its antileukemic activity in vitro.

Type II L-asparaginase (ASNase) has been approved by the FDA for treating acute lymphoid leukemia (ALL), but its therapeutic effect is limited by low catalytic efficiency and L-glutaminase (L-Gln) activity. This study utilized free energy based molecular dynamics calculations to identify residues associated with substrate binding in Bacillus licheniformis L-asparaginase II (BLASNase) with high catalytical activity. After saturation and combination mutagenesis, the mutant LGT (74 L/75G/111 T) with intensively reduced l-glutamine catalytic activity was generated. The l-glutamine/L-asparagine activity (L-Gln/L-Asn) of LGT was only 6.6 % of parent BLASNase, whereas the L-asparagine (L-Asn) activity was preserved >90 %. Furthermore, structural comparison and molecular dynamics calculations indicated that the mutant LGT had reduced binding ability and affinity towards l-glutamine. To evaluate its effect on acute leukemic cells, LGT was supplied in treating MOLT-4 cells. The experimental results demonstrated that LGT was more cytotoxic and promoted apoptosis compared with commercial Escherichia coli ASNase. Overall, our findings firstly provide insights into reducing l-glutamine activity without impacting L-asparagine activity for BLASNase to possess remarkable potential for anti-leukemia therapy.

Structure-Guided Steric Hindrance Engineering of Devosia Strain A6-243 Quinone-Dependent Dehydrogenase to Enhance Its Catalytic Efficiency.

Deoxynivalenol (DON), the most widely distributed mycotoxin worldwide, causes severe health risks for humans and animals. Quinone-dependent dehydrogenase derived from Devosia strain A6-243 (DADH) can degrade DON into less toxic 3-keto-DON and then aldo-keto reductase AKR13B3 can reduce 3-keto-DON into relatively nontoxic 3-epi-DON. However, the poor catalytic efficiency of DADH made it unsuitable for practical applications, and it has become the rate-limiting step of the two-step enzymatic cascade catalysis. Here, structure-guided steric hindrance engineering was employed to enhance the catalytic efficiency of DADH. After the steric hindrance engineering, the best mutant, V429G/N431V/T432V/L434V/F537A (M5-1), showed an 18.17-fold increase in specific activity and an 11.04-fold increase in catalytic efficiency (kcat/Km) compared with that of wild-type DADH. Structure-based computational analysis provided information on the increased catalytic efficiency in the directions that attenuated steric hindrance, which was attributed to the reshaped substrate-binding pocket with an expanded catalytic binding cavity and a favorable attack distance. Tunnel analysis suggested that reshaping the active cavity by mutation might alter the shape and size of the enzyme tunnels or form one new enzyme tunnel, which might contribute to the improved catalytic efficiency of M5-1. These findings provide a promising strategy to enhance the catalytic efficiency by steric hindrance engineering.

Improved catalytic performance and molecular insight for lipoxygenase from Enterovibrio norvegicus via directed evolution.

Lipoxygenase (LOX) holds significant promise for food and pharmaceutical industries. However, albeit its application has been hampered by low catalytic activity and suboptimal thermostability. To address the drawbacks, a directed evolution strategy was explored to enhance the catalytic activity and thermostability of LOX from Enterovibrio norvegicus (EnLOX) for the first time. After two rounds of error-prone polymerase chain reaction (error-prone PCR) and one generations of sequential DNA shuffling, all of four different mutants showed a significant increase in the specific activity of EnLOX, ranging from 132.07 ± 9.34 to 330.17 ± 18.54 U/mg. Among these mutants, D95E/T99A/A121H/S142N/N444W/S613G (EAHNWG) exhibited the highest specific activity, which was 8.25-fold higher than the wild-type enzyme (WT). Meanwhile, the catalytic efficiency (K cat /K m) of EAHNWG was also improved, which was 13.61 ± 1.67 s-1 µM-1, in comparison to that of WT (4.83 ± 0.38 s-1 µM-1). In addition, mutant EAHNWG had a satisfied thermostability with the t 1/2,50 °C value of 6.44 ± 0.24 h, which was 0.4 h longer than that of the WT. Furthermore, the molecular dynamics simulation and structural analysis demonstrated that the reduction of hydrogen bonds number, the enhancement of hydrophobic interactions in the catalytic pocket, and the improvement of flexibility of the lid domain facilitated structural stability and the strength of substrate binding capacity for improved thermal stability and catalytic efficiency of mutant LOX after directed evolution. Overall, these results could provide the guidance for further enzymatic modification of LOX with high catalytic performance for industrial application.

Enhancing the Physicochemical Attributes of Dough and Noodles through the Incorporation of Bacillus vallismortis Laccase.

This investigation examined how the Bacillus vallismortis laccase (rBVL-MRL522) influenced the physicochemical characteristics, structural attributes, and functional capabilities of both dough and noodles. Incorporating rBVL-MRL522 (1 U/g) did not lead to a substantial change in the water absorption of wheat flour. However, the introduction of rBVL-MRL522 caused a significant elongation in the formation time of wheat flour dough, extending it by 88.9%, and also resulted in a 50% increase in the stabilization duration of wheat flour dough. Furthermore, adding rBVL-MRL522 led to a proportional rise in both the elastic and viscous moduli (G'' of the dough, signifying that r-BVL (rBVL-MRL522) has a beneficial effect on the gluten strength of the dough. Integrating rBVL-MRL522 promoted the consolidation of the gluten-based cross-linked structure within the dough, decreasing the size of starch particles and, more evenly, the dispersion of these starch particles. In the noodle processing, adding rBVL-MRL522 at a rate of 1 U/g raised the L* value of the noodles by 2.34 units compared to the noodles prepared without the inclusion of rBVL-MRL522. Using a greater amount of rBVL-MRL522 (2 U/g) substantially increased the hardness of the noodles by 51.31%. Additionally, rBVL-MRL522 showed a noteworthy enhancement in the elasticity, cohesiveness, and chewiness of the noodles. In conclusion, rBVL-MRL522 promoted the cross-linking gluten, leading to a more extensive and condensed three-dimensional network structure in raw and cooked noodles. As a result, this study offers valuable insights into the environmentally friendly processing of dough and associated products.

Comparative Transcriptome Analysis Revealing the Enhanced Volatiles of Cofermentation of Yeast and Lactic Acid Bacteria on Whole Wheat Steamed Bread Dough.

To reveal the underlying mechanism of enhanced volatiles of whole wheat steamed bread, the current study screened Saccharomyces cerevisiae Y5 and Lactiplantibacillus plantarum L7 from sourdough and studied the synergetic effect of cofermentation on the volatiles of steamed bread and fermented dough by comparative transcriptome analysis. Cofermentation significantly improved the types and concentration of volatiles in addition to the improved specific volume and texture. Genes involved in galactose, starch, and glucose metabolism and genes encoding pyruvate oxidase and ß-galactosidase were significantly upregulated in S. cerevisiae and L. plantarum, respectively. Expression of the OPT2 encoding oligopeptide transporter in S. cerevisiae was upregulated, which facilitated the transmembrane transport of oligopeptide and amino acid into yeast cells. Genes involved in the synthesis and metabolism of amino acids, lipids, and ester compounds in L. plantarum changed significantly, and gene encoding acetic acid kinase was upregulated. Moreover, the quorum sensing-related genes in S. cerevisiae and L. plantarum were upregulated.

Establishment of real-time fluorescence and visual LAMP for rapid detection of Escherichia coli O157:H7 and kits construction.

Escherichia coli O157:H7 is a common pathogenic bacterium in food and water that can pose a threat to human health. The aim of this study was to develop loop-mediated isothermal amplification (LAMP) method for the detection of E. coli O157:H7 in food based on the specific gene Ecs_2840 and to construct rapid detection kits based on the established methods. Specifically, we established two methods of real-time fluorescent LAMP (RT-LAMP) and visual LAMP with calcein as an indicator. In pure bacterial culture, the cell sensitivity and genomic sensitivity of the RT-LAMP kit were 8.8 × 100 CFU ml-1 and 4.61 fg µl-1, respectively. The sensitivity of the visual LAMP kit was 2.35 × 100 CFU ml-1 and 4.61 fg µl-1. Both kits had excellent specificity and anti-interference performance. In addition, milk inoculated with 2.26 × 100 CFU ml-1E. coli O157:H7 could be detected within the reaction time after enrichment for 3 h. The results showed that the LAMP kits were rapid, sensitive, and specific for the detection of E. coli O157:H7 in food and had good application prospects in food safety surveillance.

Effects of the deletion and substitution of thioesterase on bacillomycin D synthesis.

OBJECTIVES: The importance of thioesterase domains on bacillomycin D synthesis and the ability of different thioesterase domains to selectively recognize and catalyze peptide chain hydrolysis and cyclization were studied by deleting and substituting thioesterase domains. RESULTS: No bacillomycin D analogs were found in the thioesterase-deleted strain fmbJ-ΔTE, indicating that the TE domain was essential for bacillomycin D synthesis. Then the thioesterase in bacillomycin D synthetases was replaced by the thioesterase in bacillomycin F, iturin A, mycosubtilin, plipastatin and surfactin synthetases. Except for fmbJ-S-TE, all others were able to synthesize bacillomycin D homologs because a suitable recombination site was selected, which maintained the integrity of NRPSs. In particular, the yield of bacillomycin D in fmbJ-IA-TE, fmbJ-M-TE and fmbJ-P-TE was significantly increased. CONCLUSION: This study expands our understanding of the TE domain in bacillomycin D synthetases and shows that thioesterase has excellent potential in the chemical-enzymatic synthesis of natural products or their analogs.

The global regulator SpoVG regulates Listeria monocytogenes biofilm formation.

Biofilms provide a suitable environment for L. monocytogenes and are the cause of enormous risks in the food industry. SpoVG is a global regulatory factor that plays a vital role in physiological activity of L. monocytogenes. We constructed spoVG mutant strains to investigate the effects of these mutants on L. monocytogenes biofilms. The results show that L. monocytogenes biofilm formation was decreased by 40%. Furthermore, we measured biofilm related phenotypes to study the regulation of SpoVG. The motility capacity of L. monocytogenes was found to decrease after the deletion of spoVG. The cell surface properties changed in the spoVG mutant strains, with an increase in both the cell surface hydrophobicity and the auto-aggregation capacity after spoVG deletion. SpoVG mutant strains were found to be more sensitive to antibiotics, and had a reduced tolerance to inappropriate pH, salt stress and low temperature. The RT-qPCR results showed that SpoVG effectively regulated the expression of genes related to quorum sensing, flagella, virulence and stress factors. These findings suggest that spoVG has potential as a target to decrease biofilm formation and control L. monocytogenes contamination in the food industry.

Computational Insights and In Silico Characterization of a Novel Mini-Lipoxygenase from Nostoc Sphaeroides and Its Application in the Quality Improvement of Steamed Bread.

Lipoxygenase (EC1.13.11.12, LOX) has been potentially used in the food industry for food quality improvement. However, the low activity, poor thermal stability, narrow range of pH stability, as well as undesirable isoenzymes and off-flavors, have hampered the application of current commercial LOX. In this study, a putative mini-lipoxygenase gene from cyanobacteria, Nostoc sphaeroides (NsLOX), was cloned and expressed in E. coli BL21. NsLOX displayed only 26.62% structural identity with the reported LOX from Cyanothece sp., indicating it as a novel LOX. The purified NsLOX showed the maximum activity at pH 8.0 and 15 °C, with superior stability at a pH range from 6.0 to 13.0, retaining about 40% activity at 40 °C for 90 min. Notably, NsLOX exhibited the highest specific activity of 78,080 U/mg towards linoleic acid (LA), and the kinetic parameters-Km, kcat, and kcat/Km-attain values of 19.46 µM, 9199.75 s-1, and 473.85 µM-1 s-1, respectively. Moreover, the activity of NsLOX was obviously activated by Ca2+, but it was completely inhibited by Zn2+ and Cu2+. Finally, NsLOX was supplied in steamed bread and contributed even better improved bread quality than the commercial LOX. These results suggest NsLOX as a promising substitute of current commercial LOX for application in the food industry.

Antiobesity effect of L-arabinose via ameliorating insulin resistance and modulating gut microbiota in obese mice.

OBJECTIVES: The global prevalence of obesity, a chronically trophic metabolic disease, has garnered significant attention. The aim of this study was to investigate L-arabinose, a unique functional sugar that improves insulin resistance and intestinal environment while promoting probiotic proliferation, for its potential in preventing obesity induced by a high-fat and high-sugar (HFHS) diet in mice. METHODS: The L-arabinose group was intragastrically administered with 0.4 mL 60 mg/(kg body weight) L-arabinose for 8 wk. The metformin group was intragastrically administered at 0.4 mL 300 mg/(kg body weight), as a positive control group. RESULTS: Treatment with L-arabinose resulted in a reduction of various obesity symptoms, such as prevented weight gain, increased liver-to-body ratio, decreased insulin, homeostasis model assessment for insulin resistance (HOMA-IR) index, and lipopolysaccharide (LPS) levels, as well as improved insulin resistance, reduced fat volume, inhibited hepatic steatosis, and repaired the pancreas. The L-arabinose treatment also improved lipid metabolism and inflammatory response, decreased the Firmicutes-to-Bacteroidetes ratio at the phylum level, and increased the relative abundance of Parabacteroides gordonii and Akkermansia muciniphila at the species level. CONCLUSION: Based on these results, L-arabinose could be a promising candidate for combating obesity and obesity-related diseases by regulating insulin resistance and gut microbiota.

Effects of monolauroyl-galactosylglycerol on membrane fatty acids and properties of Bacillus cereus.

The purpose of this study was to provide new ideas for the antibacterial mechanism of monolauroyl-galactosylglycerol (MLGG) from the perspective of cell membranes. The changes in cell membrane properties of Bacillus cereus (B. cereus) CMCC 66,301 exposed to different concentrations (1 × MIC (minimum inhibitory concentration), 2 × MIC, 1 × MBC (minimum bacterial concentration)) of MLGG were evaluated. It was found that the lag phase of B. cereus cells was prolonged at low concentration MLGG (1 × MIC and 2 × MIC), while about 2 log CFU/mL reduction in B. cereus populations were observed when exposed to high concentration MLGG (1 × MBC). MLGG treated B. cereus displayed obvious membrane depolarization, while membrane permeability had no change using PI (propidium iodide) staining. Significant increase in the membrane fluidity in response to MLGG exposure occurred, which was consistent with the modification of membrane fatty acids compositions, where the relative content of straight-chain fatty acids (SCFAs) and unsaturated fatty acids (UFAs) increased, while branched-chain fatty acids (BCFAs) decreased significantly. The decreased transition Tm value and cell surface hydrophobicity was also observed. Additionally, effect of MLGG on bacterial membrane compositions were explored at the submolecular level by infrared spectroscopy. Resistance tests of B. cereus to MLGG had demonstrated the advantages of MLGG as a bacteriostatic agent. Collectively, these studies indicate that modifying the fatty acid composition and properties of cellular membranes through MLGG exposure is crucial for inhibiting bacteria growth, providing new insights into the antimicrobial mechanisms of MLGG. KEY POINTS: • Monolauroyl-galactosylglycerol inserted into B. cereus lipid bilayer membrane • Monolauroyl-galactosylglycerol treatment caused B. cereus membrane depolarization • Monolauroyl-galactosylglycerol resulted in B. cereus membrane fatty acids alteration.

Transcriptomic analysis reveals that Bacillomycin D-C16 induces multiple pathways of disease resistance in cherry tomato.

BACKGROUND: Bacillomycin D-C16 can induce resistance in cherry tomato against pathogens; however, the underlying molecular mechanism is poorly understood. Here, the effect of Bacillomycin D-C16 on induction of disease resistance in cherry tomato was investigated using a transcriptomic analysis. RESULTS: Transcriptomic analysis revealed a series of obvious enrichment pathways. Bacillomycin D-C16 induced phenylpropanoid biosynthesis pathways and activated the synthesis of defense-related metabolites including phenolic acids and lignin. Moreover, Bacillomycin D-C16 triggered a defense response through both hormone signal transduction and plant-pathogen interactions pathways, and increased the transcription of several transcription factors (e.g., AP2/ERF, WRKY and MYB). These transcription factors might contribute to the further activated the expression of defense-related genes (PR1, PR10 and CHI) and stimulated the accumulation of H2O2. CONCLUSION: Bacillomycin D-C16 can induce resistance in cherry tomato by activating the phenylpropanoid biosynthesis pathway, hormone signal transduction pathway and plant-pathogen interactions pathway, thus activating comprehensive defense reaction against pathogen invasion. These results provided a new insight into the bio-preservation of cherry tomato by the Bacillomycin D-C16.

Allergenicity, assembly and applications of ovalbumin in egg white: a review.

Ovalbumin (OVA), the most abundant protein in egg whites, has been widely used in various industries. Currently, the structure of OVA has been clearly established, and the extraction of high-purified OVA has become feasible. However, the allergenicity of OVA is still a serious problem because it can cause severe allergic reactions and may even be life-threatening. The structure and allergenicity of the OVA can be altered by many processing methods. In this article, a detailed description on the structure and a comprehensive overview on the extraction protocols and the allergenicity of OVA was documented. Additionally, the information on assembly and potential applications of OVA was summarized and discussed in detail. Physical treatment, chemical modification, and microbial processing can be applied to alter the IgE-binding capacity of OVA by changing its structure and linear/sequential epitopes. Furthermore, research indicated that OVA could assemble with itself or other biomolecules into various forms (particles, fibers, gels, and nanosheets), which expanded its application in the food field. OVA also shows excellent application prospects, including food preservation, functional food ingredients and nutrient delivery. Therefore, OVA demonstrates significant investigation value as a food grade ingredient.