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In Bacillus, the spore formation process is associated with the synthesis and release of secondary metabolites. A large number of studies have been conducted to systematically elucidate the pathways and mechanisms of spore formation. However, there are no studies have explored the relationship between secondary metabolites and spores. In this study, we investigated the relationship between its secondary metabolite bacillomycin D (BD) and spores using the simpler dipicolonic acid fluorimetry assay for spore counting in Bacillus amyloliquefaciens fmbJ. Our results showed that BD could promote the spore formation of B. amyloliquefaciens fmbJ and had a synergistic effect with certain concentrations of Mn2+. When 15.6 mg/L of BD and 1 mM of Mn2+ were added, the number of fmbJ spores increased from 1.42 × 108 CFU/mL to 2.02 × 108 CFU/mL after 36 h of incubation. The expressions of spore formation (kinA, kinB, kinC, kinD, kinE and spo0A) and Mn-related genes (mntA, mntH, mneS, mneP) were studied by RT-PCR. The results indicated that BD and Mn2+ promoted the spore formation of fmbJ by stimulating the transcription of kinB, kinD and increasing the influence of spo0F-spo0A phosphorylation transmission. This study provided a new idea to improve the spore production of B. amyloliquefaciens and laid the foundation for its industrial production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Acid-modified attapulgite (H-ATP) could adsorb up to 93.13% of bacillomycin D. • 0.6 % of the composites were effective at removing 89.06 % of Aflatoxin B 1 at 50 °C. • The composite materials combined both fungal growth inhibition and detoxification. Molds and mycotoxins pose severe threats to health. Bacillomycin D (BD) can effectively inhibit mold growth. Attapulgite (ATP) can provide a good carrier for antimicrobial agents. Natural ATP was acid-modified to obtain H-ATP. It was used to load BD to obtain a novel composite material (H-ATP-BD). The results showed H-ATP had better adsorption performance than ATP. BD was adsorbed up to 93.13 % by adding 30 mg H-ATP and stirring at 40 ℃ for 120 min. Fourier transform infrared spectra (FTIR), size and zeta potential, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results confirmed successful loading of BD onto H-ATP. The composite showed good inhibition of Aspergillus and adding 0.6 % H-ATP-BD composite was effective in removing 89.06 % of aflatoxin B 1 (AFB 1) at 50 °C. Model fitting indicated that AFB 1 removal was a spontaneous exothermic reaction. This research will lay the foundation for the development of efficient and green antimicrobial and toxin-reducing materials. [ABSTRACT FROM AUTHOR]

Accumulating evidence suggested that suppression of Propionibacterium acnes-induced inflammation was a promising strategy to alleviate acne vulgaris. This study evaluated the alleviating effect of surfactin-oleogel on P. acnes-induced inflammatory acne vulgaris in mice. Epidermis morphology and histopathological examination showed that surfactin-oleogel effectively ameliorated the P. acnes-induced epidermis swelling and erythema. Surfactin-oleogel reduced the epidermis thickness to 48.52% compared to the model control group. The colony of P. acnes in the epidermis was decreased by 1 log CFU/mL after receiving surfactin-oleogel treatment. Furthermore, surfactin-oleogel attenuated oxidative stress in the epidermis by increasing the activities of superoxide dismutase, catalase, and glutathione peroxidase. In addition, the expression of inducible nitric oxide synthase, nitric oxide, cyclooxygenase-2, pro-inflammatory cytokines (e.g. tumour necrosis factor-α and interleukin-1β), and nuclear factor kappa-B in the epidermis were reduced after treating with surfactin-oleogel. Moreover, total cholesterol and free fatty acids were decreased, whereas the treatment of surfactin-oleogel increased triglycerides and linoleic acid content. Besides, immunohistochemical assay and real-time PCR analysis indicated that surfactin-oleogel blocked the TLR2-mediated NF-κB signalling pathways in the epidermis. Consequently, our results demonstrated that surfactin-oleogel had antibacterial and anti-inflammation activities to treat P. acnes-induced inflammatory acne vulgaris. Key points • Surfactin-oleogel effectively relieves inflammation and oxidative stress caused by P. acnes. • Surfactin-oleogel effectively reduced the P. acnes colony. • Surfactin-oleogel relieves P. acnes-induced inflammation by inactivated the TLR-mediated NF-κB. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to explore the protective effect of broccoli microgreens juice (BMJ) during C57BL/6J mice obesity development. Methods: The obese model mice, induced by feeding high-fat diet (HFD), were treated with BMJ by gavage for 10 weeks. Melbine was gavaged at 300 mg/(kg bw)/d, as a positive control group. Results: BMJ supplementation significantly reduced white adipose tissues (WAT) mass, the body weight and adipocyte size, and increased water intake in HFD-fed mice. Moreover, it improved glucose tolerance, reduced insulin level and HOMA-IR value, and alleviated insulin resistance. Compared with the HFD group, BMJ supplementation significantly increased the relative abundance of Bacteroidetes and decreased the ratio of Firmicutes to Bacteroidetes at the phylum level, and enriched Bacteroides_acidifaciens at the species level. These changes in the composition of gut microbiota are associated with the production of short-chain fatty acids (SCFAs), and reduced LPS levels, and had an obvious anti-inflammatory effect. Conclusions: These findings suggested that the protective effects of BMJ on diet-induced obesity may be involved in gut microbiota–SCFAs–LPS–inflammatory axis. In addition, BMJ can enhance liver antioxidant capacity and reduce liver fat accumulation. Consequently, these results sustain BMJ as a novel functional food for obesity, on the basis of its opposing effects on HFD-induced obesity in mice. [ABSTRACT FROM AUTHOR]

Brevibacillins are broad-spectrum cationic antimicrobial lipopeptides produced by Brevibacillus laterosporus fmb70 CGMCC 18426. The antibacterial mode of brevibacillins against Salmonella typhimurium CICC 21493 was investigated by quantum chemistry calculation in this study. The addition of LPS, Mg2+, and Ca2+ partially reduced the antimicrobial activity of brevibacillin and brevibacillin V against S. typhimurium, which indicated that the two cationic lipopeptides could bind to LPS and displaced the divalent cations on the LPS network. Release of LPS from S. typhimurium by brevibacillin and brevibacillin V resulted in destroying the dense LPS network and increasing the permeability of the outer membrane. Quantum chemistry calculation analysis revealed that Lys7 is the most critical amino acid residue to destroy the outer membrane. The total average N-H charge difference of the three protonated amino groups (Orn3-NH3, Lys7-NH3, and Lys10-NH3) determined the ability of brevibacillin V to bind LPS stronger than brevibacillin. Calcein complete leakage from liposomes and release of DiSC3-5 from the cytoplasmic membrane (CM) indicated that brevibacillin and brevibacillin V may destroy the CM. Brevibacillin and brevibacillin V exhibited their antimicrobial activities through membrane damages, where the OM permeability with high concentration of 64-256 µg/mL and membrane damage of CM with a low concentration of 4 μg/mL. Our finding might be helpful to understand the broad-spectrum antimicrobial mechanism of cationic lipopeptide and to design the novel antimicrobial peptide. Key points: • Brevibacillin V had stronger affinity for LPS than brevibacillin. • The N-H charge difference was the key of the difference in the affinity to LPS. • Brevibacillins inhibited Salmonella by displacing the divalent cations on the LPS. [ABSTRACT FROM AUTHOR]

Widespread foodborne pathogen Listeria monocytogenes exhibits a pronounced fatality rate among individuals with compromised immune systems, the elderly, and pregnant women. A simple and user-friendly approach is required to identify L. monocytogenes. A distinctive thermostatic nucleic acid amplification technology called polymerase spiral reaction (PSR) has been extensively employed in the identification of foodborne pathogens. In the study, a straightforward and intuitive approach for identifying L. monocytogenes in fresh-cut fruit was established using PSR in conjunction with hydroxy naphthol blue (HNB). Following optimization, the system's primary constitutes-betaine, dNTP, and MgSO 4 were found to be 0.5 M, 1.0 mM, and 6 mM, respectively. Six strains of non- L. monocytogenes were used to test the assay's specificity. The PSR assay performed at 65 °C for 50 min demonstrated the capability to detect L. monocytogenes at level as low as 1 × 10−4 ng/μL DNA per tube and 5.1 × 101 CFU/g of freshly cut fruit. Notably, the sensitivity of this approach surpassed that of PCR by10-fold (1 × 10−3 ng/μL). In order to detect L. monocytogenes , the PSR assay was designed to be rapid, accurate, effective, and apparatus free. This innovative assay has provided researchers a fresh perspective on identification harmful microorganisms. [Display omitted] • A novel method of PSR for detecting L. monocytogenes was established. • The detection limit of L. monocytogenes was 1 × 10−4 ng/μL in pure DNA. • This assay could identify L. monocytogenes at 5.1 × 101 CFU/g of freshly cut fruit. • The sensitivity was 10-fold higher than PCR in pure DNA. [ABSTRACT FROM AUTHOR]

Plantaricin EF, a kind of natural antibacterial substance, has shown inhibitory effect on most pathogen and spoilage microorganisms, which possessed great potential in food preservation. However, the lower production of plantaricin EF has limited its large-scale production and application. In this study, the effect of maltose on plantaricin EF production and its regulation mechanism in Lactobacillus plantarum 163 were investigated. Maltose significantly improved the biomass and plantaricin EF production, which increased by 3.35 and 3.99 times comparing to the control without maltose, respectively. The maximum production of plantaricin E and F in fed-batch fermentation were 10.55 mg/L and 22.94 mg/L, respectively. Besides, qPCR results showed that maltose remarkably improved transcription of plnA, plnB, plnD, plnE, plnF, plnG1 and plnH, and heighten transcription of lamR, lamK, hpk6 and rrp6. These results provided an effective method to enhance plantaricin EF production and revealed a possible regulatory mechanism from transcriptome results that hpk6, rrp6, lamK and lamR were relative to plantaricin EF production. Genes, hpk6 and rrp6, promote transcription of plnG1, whereas lamK and lamR enhance transcription of plnA, plnB and plnD, which increased plantaricin EF production. Keypoints: • Maltose was proved to be effective in promoting the biosynthesis of plantaricin EF. • Maltose promoted the transcription of biosynthesis and secretion genes of plantaricin EF. • Up-regulation of genes lamR, lamK, hpk6 and rrp6 heightened the plantaricin EF production. [ABSTRACT FROM AUTHOR]

Biosurfactants are amphiphilic compounds that composed of hydrophilic and hydrophobic moieties, which possess the ability of self-organizing between phases, reducing the interfacial tension, and forming aggregates such as micelles. This spontaneous process results in significant changes in surface properties that directly influence the adherence of microorganisms. In this study, the ability of surfactin, a biosurfactant produced by Bacillus subtilis in reducing adhesion and disrupting the presence of biofilm of Staphylococcus aureus (S. aureus) on several surfaces, was investigated. Significant biofilm removal was observed on glass, polystyrene, and stainless steel surfaces. Furthermore, we explored the probable mechanism about how surfactin affected S. aureus biofilm formation. Based on our findings, surfactin had a significant effect on the polysaccharides production and especially decreased the percentage of alkali-soluble polysaccharide in biofilms. It also down-regulated the expression of icaA and icaD significantly, which are necessary for the important constituents to take shape of staphylococcal biofilm. In addition, it was found that the lipopeptide affected the quorum sensing (QS) system in S. aureus through regulating the auto inducer 2 (AI-2) activity, which has been reported to be negative for biofilm formation in S. aureus. These above properties could be applied in developing surfactin as a potential pre-coating agent on material surfaces to prevent S. aureus biofilm formation. [ABSTRACT FROM AUTHOR]

Transcriptomic analysis reveals that bacillomycin D-C16 induces multiple pathways of disease resistance in cherry tomato. B Correction: BMC Genomics 24, 218 (2023) b https://doi.org/10.1186/s12864-023-09305-5 Following publication of the original article [[1]], it was reported that there was an error in the presentation of Jing Sun, Yuanhong Li and Yingjian Lu's affiliations. [Extracted from the article]

Docosahexaenoic acid (DHA), one of the most important omega-3 polyunsaturated fatty acids (PUFAs), shows significant health benefits for human beings. In order to stabilize nutrients like DHA, microemulsion is normally used through the addition of surfactant, and surfactin as a natural peptide biosurfactant shows strong surface activity. In this study, we investigated the effects of surfactin on the stability of docosahexaenoic acid single cell oil (DHASCO) microemulsions. The microemusion region was significantly increased with elevated surfactin concentration from 0 to 0.2 mmol/L, and reached a maximum. The o/w region of DHASCO microemulsion could significantly increase and the diameters of microemulsion particles were reduced from 140 to 15 nm after addition of 0.2 mmol/L surfactin into emulsion system. Generally, the physical and anti-oxidation stability of the o/w DHASCO microemulsion with surfactin was highly enhanced. DHA oxidation in microemulsion with surfaction was significantly reduced even stored at 37 °C for 60 days as compared to non-surfactin. The excellent properties of microemulsion with surfactin could be useful in functional food and medicine. [ABSTRACT FROM AUTHOR]

Although several studies have reported PCR assays for distinguishing Cronobacter sakazakii from other species in the genus, reports regarding assay sensitivity and specificity, as well as applications for food testing, are lacking. Hence, the objective of this study was to develop a sensitive and reliable PCR-based method for detection of C. sakazakii by screening for specific target genes. The genome sequence of C. sakazakii in the GenBank database was compared with that of other organisms using BLAST. Thirty-eight DNA fragments unique to C. sakazakii were identified, and primers targeting these sequences were designed. Finally, 3 primer sets (CS14, CS21, and CS38) were found to be specific for C. sakazakii by PCR verification. The detection limit of PCR assays using the 3 pairs of primers was 1.35 pg/µL, 135 fg/µL, and 135 fg/µL, respectively, for genomic DNA, and 5.5 x 105, 5.5 x 10³, 5.5 x 10³ cfu/mL, respectively, using pure cultures of the bacteria, compared with 13.5 pg/µLand 5.5 x 105 cfu/mLfor primer set SpeCronsaka, which has been previously described. Cronobacter sakazakii were detected in artificially contaminated powdered infant formula (PIF) by PCR using primer sets CS21 and CS38 after 8 h of enrichment. The detection limit was 5.5 x 10-1 cfu/10 g of PIF. Thus, the PCR assay can be used for rapid and sensitive detection of C. sakazakii in PIF. [ABSTRACT FROM AUTHOR]

Hyperuricemia is a critical threat to human health, and conventional medical treatment only aims to treat acute gouty arthritis. Purine diet-mediated chronic hyperuricemia and related syndromes are neglected in clinical therapeutics. In this study, the prevention ability of Lacticaseibacillus rhamnosus Fmb14, screened from Chinese yogurt, was evaluated in chronic purine-induced hyperuricemia (CPH) mice. After 12 weeks of Fmb14 administration, serum uric acid (SUA) in CPH mice decreased by 36.8 %, from 179.1 to 113.2 µmol/L, and the mortality rate decreased from 30 % to 10 %. The prevention role of Fmb14 in CPH was further investigated, and the reduction of uric acid by Fmb14 was attributed to the reduction of XOD (xanthine oxidase) in the liver and URAT1 in the kidney, as well the promotion of ABCG2 in the colon. Fmb14 administration Increased ZO-1 and Occludin expression in the colon and decreased fibrosis degree in the kidney indicated that Fmb14 administration had preventive effects through the gut-kidney axis in CPH. In specific, Fmb14 administration upregulated the diversity of gut microbiota, increased short-chain fatty acids (SCFA) by 35 % in colon materials and alleviated the inflammatory response by reducing biomarkers levels of IL-1β, IL-18 and TNF-α at 11.6 %, 21.7 % and 26.5 % in serum, compared to CPH group, respectively. Additionally, 16 S rRNA sequencing showed 31.5 % upregulation of Prevotella, 20.5 % and 21.6 % downregulation of Ruminococcus and Suterella at the genus level, which may be a new gut microbial marker in hyperuricemia. In conclusion, Fmb14 ameliorated CPH through the gut-kidney axis, suggesting a new strategy to prevent hyperuricemia. [Display omitted] • Oral administration of L. rhamnosus Fmb14 prevents chronic purine-induced hyperuricemia (CPH) in mice. • L. rhamnosus Fmb14 prevented hyperuricemia through modulate purine metabolism and uric acid excretion system in CPH mice. • L. rhamnosus Fmb14 restored microbiota dysbiosis and enhanced gut barriers by short chain fatty acid production. • New potential gut microbial marker to prevent CPH was founded. • L. rhamnosus Fmb14 ameliorated hyperuricemia induced renal fibrosis through gut-kidney axis. [ABSTRACT FROM AUTHOR]

To improve the bioavailability of curcumin, surfactin was used to prepare curcumin-loaded nanoemulsions (Cur-NEs). Moreover, the physicochemical properties, digestive characteristics, as well as inhibition activity to Caco-2 cells of Cur-NEs were measured. Furthermore, the morphological analysis revealed that Cur-NEs with 320 mg/L surfactin appeared spherical nanoparticale (23.23 ± 2.86 nm) and uniform distribution. The encapsulation efficiency of Cur-NEs with 320 mg/L surfactin was 97.25 ± 1.28%. Simulated gastrointestinal digestion results indicated that surfactin elevated the sustained-release characteristics and higher bioaccessibility (40.92 ± 2.84%) of curcumin. Besides, Cur-NEs with 320 mg/L surfactin exhibited excellent stability in different temperature, pH and light irradiation. In addition, the inhibition of Cur-NEs with 320 mg/L surfactin to Caco-2 cells was 71.29%. Biochemical analysis showed that Cur-NEs enhanced the activity of lactate dehydrogenase, superoxide dismutase, catalase and glutathione peroxidase, as well as the reactive oxygen species content. RT-PCR and ELISA results also revealed that Cur-NEs inhibited Caco-2 cells through the activated mitochondria-mediated pathway. This study provided a strategy to encapsulate curcumin in nanoparticles with surfactin for improving bioavailability. [Display omitted] • Surfactin decreased the particle size of emulsion with curcumin to nano-scale. • Surfactin supplement in emulsion enhanced the encapsulation efficiency of curcumin. • Curcumin nanoemulsion with surfactin had good physical and storage stability. • Surfactin in nanoemulsion elevated the sustained-release characteristics of curcumin. • Surfactin promoted the inhibition of curcumin nanoemulsion to Caco-2 cells. [ABSTRACT FROM AUTHOR]

• Effects of varied food processing on glucoraphanin (GLR) and sulforaphane (SLR) are reviewed. • Microwaving promotes formation of SLR from GLR better than fermentation/steaming. • Boiling/blanching decrease GLR and SLR levels while freezing protect their losses. • Stir-frying varies GLR and SLR contents in different cooking conditions. Brassica vegetables are widely consumed mostly after processing and cooking. These processing and cooking methods not only can affect the taste, texture, flavor and nutrients of these vegetables, but also influence the levels of some important bioactive compounds, such as glucosinolates (GLSs). Glucoraphanin (GLR) is the most abundant GLSs and its hydrolyzed component, sulforaphane (SLR), is the most powerful anti-cancer compound in brassica vegetables. In this review, we find out that varied treatments impact the retention of GLR and the formation of SLR differently. Be specific, 1) freezing can avoid the losses of GLR while short-time microwaving, short-time steaming and fermentation promote the biotransformation from GLR to SLR; 2) Boiling and blanching cause the largest losses of GLR and SLR, while freezing significantly protect their losses.; 3) Stir-frying varies the levels of GLR and SLR in different cooking conditions. [ABSTRACT FROM AUTHOR]

Listeria monocytogenes biofilms represent a continuous source of contamination, leading to serious food safety concerns and economic losses. This study aims to develop novel nisin-loaded chitosan nanoparticles (CSNPs) functionalized with DNase I and evaluate its antibiofilm activity against L. monocytogenes on food contact surfaces. Nisin-loaded CSNPs (CS-N) were first prepared by ionic cross-linking, and DNase I was covalently grafted on the surface (DNase-CS-N). The NPs were subsequently characterized by Zetasizer Nano, transmission electron microscopy, Fourier transform infrared (FT-IR), and X-ray diffraction (XRD). The antibiofilm activity of NPs was evaluated against L. monocytogenes on polyurethane (PU). The DNase-CS-N was fabricated and characterized with quality attributes (particle size-427.0 ± 15.1 nm, polydispersity [PDI]-0.114 ± 0.034, zeta potential-+52.5 ± 0.2 mV, encapsulation efficiency-46.5% ± 3.6%, DNase conjugate rate-70.4% ± 0.2). FT-IR and XRD verified the loading of nisin and binding of DNase I with chitosan. The DNase-CS-N caused a 3 log colony-forming unit (CFU)/cm 2 reduction of L. monocytogenes biofilm cells, significantly higher than those in CSNPs (1.4 log), CS-N (1.8 log), and CS-N in combination with DNase I (2.2 log) treatment groups. In conclusion, nisin-loaded CSNPs functionalized with DNase I were successfully prepared and characterized with smooth surface and nearly spherical shape, high surface positive charge, and good stability, which is effective to eradicate L. monocytogenes biofilm cells on food contact surfaces, exhibiting great potential as antibiofilm agents in food industry. PRACTICAL APPLICATION: Listeria monocytogenes biofilms are a common safety hazard in food processing. In this study, novel nanoparticles were successfully constructed and are expected to be a promising antibiofilm agent in the food industry., (© 2024 Institute of Food Technologists.)

Globally, type 2 diabetes (T2DM) is on the rise. Maintaining a healthy diet is crucial for both treating and preventing T2DM.As a common vegetable in daily diet, broccoli has antioxidant, anti-inflammatory and anticarcoma physiological activities. We developed a mouse model of type 2 diabetes and carried out a systematic investigation to clarify the function of broccoli in reducing T2DM symptoms and controlling intestinal flora. The findings demonstrated that broccoli could successfully lower fasting blood glucose (FBG), lessen insulin resistance, regulate lipid metabolism, lower the levels of TC, TG, LDL-C, and MDA, stop the expression of IL-1β and IL-6, and decrease the harm that diabetes causes to the pancreas, liver, fat, and other organs and tissues. Furthermore, broccoli altered the intestinal flora's makeup in mice with T2DM. At the genus level, the relative abundance of Allobaculum decreased, and that of Odoribacter and Oscillospira increased; At the family level, the relative abundances of Odoribacteraceae, Rikenellaceae and S24-7 decreased, while the relative abundances of Erysipelotrichaceae and Rikenellaceae increased.

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., (Copyright © 2023. Published by Elsevier Inc.)

Curcumin is a polyphenolic compound that has been widely investigated for its health benefits. However, the clinical relevance of curcumin is limited due to its low water solubility and inefficient absorption. Therefore, curcumin is often encapsulated in nanocarriers to improve its delivery and function. In this study, composite nanoparticles composed of stearic acid-modified chitosan (SA-CS) and sodium caseinate (NaCas) were formed using sodium periodate-oxidized dextran with different molecular weights as a crosslinking agent. The effects of oxidized dextran (Odex) with different molecular weights on the composite nanoparticles were compared. The optimal SA-CS/NaCas/Odex composite nanoparticle (NPO) was obtained using an Odex (150 kDa)-to-SA-CS mass ratio of 2:1. Its size, polydispersity index (PDI), and zeta potential (ZP) were 130.2 nm, 0.149, and 25.4 mV, respectively. The particles were highly stable in simulated gastric fluid (SGF) in vitro, and their size and PDI were 172.3 nm and 0.263, respectively. The encapsulation rate of NPO loaded with curcumin (Cur-NPO) was 93% under optimal ultrasonic conditions. Compared with free curcumin, the sustained release of Cur-NPO significantly reduced to 17.9%, and free-radical-scavenging ability improved to 78.7%. In general, the optimal prepared NPO exhibited good GI stability and has potential applications in the formulation of orally bioactive hydrophobic drugs.

The maturity of tobacco leaves plays a decisive role in tobacco production, affecting the quality of the leaves and production control. Traditional recognition of tobacco leaf maturity primarily relies on manual observation and judgment, which is not only inefficient but also susceptible to subjective interference. Particularly in complex field environments, there is limited research on in situ field maturity recognition of tobacco leaves, making maturity recognition a significant challenge. In response to this problem, this study proposed a MobileNetV1 model combined with a Feature Pyramid Network (FPN) and attention mechanism for in situ field maturity recognition of tobacco leaves. By introducing the FPN structure, the model fully exploits multi-scale features and, in combination with Spatial Attention and SE attention mechanisms, further enhances the expression ability of feature map channel features. The experimental results show that this model, with a size of 13.7 M and FPS of 128.12, performed outstandingly well on the task of field maturity recognition of tobacco leaves, achieving an accuracy of 96.3%, superior to classical models such as VGG16, VGG19, ResNet50, and EfficientNetB0, while maintaining excellent computational efficiency and small memory footprint. Experiments were conducted involving noise perturbations, changes in environmental brightness, and occlusions to validate the model's robustness in dealing with the complex environments that may be encountered in actual applications. Finally, the Score-CAM algorithm was used for result visualization. Heatmaps showed that the vein and color variations of the leaves provide key feature information for maturity recognition. This indirectly validates the importance of leaf texture and color features in maturity recognition and, to some extent, enhances the credibility of the model. The model proposed in this study maintains high performance while having low storage requirements and computational complexity, making it significant for in situ field maturity recognition of tobacco leaves.

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 H 2 O 2 ., 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., (© 2023. The Author(s).)

Large preclinical evidence suggested that colitis was one of the risk factors for depression and probiotics were effective therapeutic agents to prevent the disease. The effect of Lacticaseibacillus rhamnosus Fmb14 on colitis-related depression-like behavior and its possible mechanisms were investigated. One week of DSS exposure led to the following changes in male C57BL/6N mice: a reduction in the movement distance from 2218 to 1299 cm, time in central areas from 23.6 s to 11.5 s, and time in the bright box from 217 s to 103 s, which were restored to 1816 cm, 18.4 s, and 181 s, respectively, with preadministration of Fmb14 for 8 weeks. All improvements provided by Fmb14 indicated a remarkable protective effect on depression-like behavior. Fmb14 first worked to repair intestinal barrier damage and the inflammatory response in the colon through ZO1 and Ocln enhancement and IL-1β, NF-κB and IL-6 reduction, respectively. Second, dysbiosis of the gut microbiota was modulated by Fmb14, including reduction of Akkermansia (18.9% to 5.4%), Mucispirillum (0.6% to 0.1%) and Bifidobacterium (0.32% to 0.03%). Fmb14 supplementation ameliorates the brain inflammatory response via IL-18 and NF-κB reduction and improves the blood-brain barrier via increased levels of ZO1 and Ocln. Moreover, brain activity was facilitated by an increase in BDNF and dopamine and the downregulation of GABA in the Fmb14 group. As a consequence of the modulatory effect on the dysfunction of neurotransmitters and neuroinflammation, Fmb14 prevents neurodegeneration by inhibiting neuronal apoptosis and Nissl edema. In addition, the correlation analysis further demonstrated the preventative effect of Fmb14 on depression-like behavior through the microbiota-gut-brain axis. Together, these findings demonstrated the important role of Fmb14 in biological signal transduction over the microbiota-gut-brain axis to improve mood disorders.

Ulcerative colitis (UC) is associated with brain neurotransmitter disorders and intestinal dysbiosis. Bacillus amyloliquefaciens fmb50 produces the lipopeptide surfactin, which has a wide range of biological activities. However, the effects of surfactin on DSS-induced colitis have not been reported. In the present study, oral surfactin significantly ameliorated colitis in a mouse model and reduced depression-like behavior, such as slowed walking speed, shortened movement distance in the open field test, and weakened exploration ability in the light-dark shuttle test. Surfactin noticeably improved gut microbial dysbiosis, intestinal barrier dysfunction in the colon, and blood-brain barrier dysfunction in the brain. Furthermore, the colon levels of occludin were upregulated by 68.51%, and the brain levels of occludin and ZO-1 were upregulated by 77.81% and 36.42%, respectively. Surfactin supplementation also inhibited inflammatory responses by inactivating the tumor necrosis factor-α (TNF-α), nuclear factor kappa-B (NF-κB), and NLRP3 signaling pathways in the colon and brain. Thus, we believe that surfactin improved the behavioral disorders by upregulating the levels of 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), norepinephrine (NE), and brain-derived neurotrophic factor (BDNF), suppressing the inflammatory responses, and improving the blood-brain barrier dysfunction. Surfactin also reduced the abundances of gut microbes that are related to colitis, especially targeting facultative anaerobes of the phylum Proteobacteria, and it increased the abundance of beneficial bacteria such as Lactobacillus and unidentified Prevotella . Combined with its nontoxic nature observed in this long-term study in mice, oral surfactin might be a promising intervention strategy for preventing colitis by acting on the microbiota-gut-brain axis.

A high-fat diet (HFD) easily contributes to the pathogenesis of obesity and insulin resistance. Obesity and insulin resistance have been clinical and public health challenges all over the world. Probiotic-fermented yogurt is one type of popular and functional beverage in people's daily lives. This study mainly explored the lipid- and glucose-lowering effects of Lactobacillus acidophilus NX2-6-fermented yogurt (LA-Y) in HFD-fed mice. The results showed that LA-Y administration improved the lipid profile in the serum and liver, reduced fasting blood glucose levels, and enhanced insulin sensitivity. Protein analysis showed that LA-Y treatment promoted fatty acid oxidation and suppressed de novo lipogenesis in the adipose tissue and liver. LA-Y effectively alleviated glucose metabolism disorders by activating the insulin signaling pathway, suppressing gluconeogenesis in the liver and muscle, reducing the concentration of pro-inflammatory cytokines in the serum, and promoting glycolysis and gluconeogenesis in the small intestine. LA-Y supplementation also promoted fat browning via the adiponectin/AMPKα/PGC-1α/UCP1 pathway and enhanced mitochondrial biogenesis in the liver and muscle by activating the adiponectin/AdipoR1/APPL1/AMPKα/PGC-1α pathway, leading to increased energy expenditure. Therefore, LA-Y may be a functional dairy food for preventing and alleviating diet-induced metabolic disorders.

Carbon sources alter the synthesis of exopolysaccharides (EPS) in Lactiplantibacillus plantarum . Maltose increased the EPS production of L. plantarum 163 6.5-fold. Subsequently, EPS production, transcriptome, and proteome were analyzed using glucose or maltose to further clarify the regulatory mechanism. A cAMP receptor protein (UniProtKB: F9UNI5) has been identified to control EPS synthesis in the presence of cAMP by binding to the EPS synthesis promoter P cps4A-J . Overexpression of the cAMP synthesis gene cyaA increased cAMP content and EPS production 4.5- and 2.2-fold, respectively. Furthermore, yogurt produced with L. plantarum 163-cyaA had a similar viscosity to that of commercial Greek yogurt; it had 20 and 83.7% greater viscosity than that produced with L. plantarum 163 with maltose and glucose, respectively. These findings indicated that L. plantarum 163-cyaA has potential applications in the production of functional fermented dairy products.

In addition to their biological functions, polysaccharides assist Lactiplantibacillus plantarum in resisting harsh conditions. To enhance the polysaccharide biosynthesis and increase the survival of L. plantarum in gut environment. We analyzed the transcriptional regulators that regulated the polysaccharide biosynthesis. A new transcriptional inhibitor, LsrR (UniProtKB: Q88YH7), had been identified, which repressed polysaccharide synthesis by binding to the polysaccharide synthesis promoter cps4A-J (P cps4A-J ). The EPSs and CPSs production of L. plantarum 163 was reduced by 42 % and 36 % (p < 0.05), respectively, when lsrR was overexpressed. Furthermore, alkaline shock proteins Asp2 and Asp1, heat shock protein Hsp3, and an autoinducer-2 (AI-2) related quorum-sensing regulator Rrp6 recovered the synthesis of polysaccharides to 50, 33, 55, and 60 %, respectively, by inhibiting the LsrR activity. This suggested that LsrR regulates polysaccharide synthesis in response to external stress signals such as pH, temperature, and AI-2 concentration. Finally, we showed that polysaccharides increased the survival rate of L. plantarum (Lp163-ΔlsrR) by 2.1 times during lyophilization and enhanced its tolerance to pH 2.0 and 0.2 % bile salts by 15.3 and 60 times due to increased capsular thickness and enhanced the autoaggregation. We provide critical data regarding Lactobacillus survival during preservative lyophilization and under gastrointestinal conditions., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Zhaoxin Lu reports funding was provided by Nanjing Agricultural University., (Copyright © 2022. Published by Elsevier B.V.)

In Bacillus , the spore formation process is associated with the synthesis and release of secondary metabolites. A large number of studies have been conducted to systematically elucidate the pathways and mechanisms of spore formation. However, there are no studies have explored the relationship between secondary metabolites and spores. In this study, we investigated the relationship between its secondary metabolite bacillomycin D (BD) and spores using the simpler dipicolonic acid fluorimetry assay for spore counting in Bacillus amyloliquefaciens fmbJ. Our results showed that BD could promote the spore formation of B. amyloliquefaciens fmbJ and had a synergistic effect with certain concentrations of Mn 2+ . When 15.6 mg/L of BD and 1 mM of Mn 2+ were added, the number of fmbJ spores increased from 1.42 × 10 8  CFU/mL to 2.02 × 10 8  CFU/mL after 36 h of incubation. The expressions of spore formation ( kinA , kinB , kinC , kinD , kinE and spo0A ) and Mn-related genes ( mntA , mntH , mneS , mneP ) were studied by RT-PCR. The results indicated that BD and Mn 2+ promoted the spore formation of fmbJ by stimulating the transcription of kinB , kinD and increasing the influence of spo0F - spo0A phosphorylation transmission. This study provided a new idea to improve the spore production of B. amyloliquefaciens and laid the foundation for its industrial production., Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-01026-9., Competing Interests: Conflicts of interestThe authors declare that they have no conflict of interest., (© Association of Microbiologists of India 2022.)

Ulcerative colitis (UC) is becoming an increasingly serious health problem. This study aimed to investigate the effect of a newly isolated Lactobacillus species that produces feruloyl esterase (FAEb) on dextran sodium sulfate (DSS)-induced UC in mice. In this study, FAEb supplementation slowed body weight loss and mitigated colon length shortening, the severity of fecal occult blood, and increases in the disease activity index (DAI) in UC model mice. FAEb supplementation was also shown to reduce the expression of proinflammatory factors, increase the antioxidant capacity, improve the production of beneficial short-chain fatty acids (SCFAs), upregulate the expression of tight junction proteins, reduce the histopathological scores, and reduce mucous barrier damage in the gut. Furthermore, FAEb supplementation was shown to inhibit inflammatory NF-κB signaling pathway activity, increase the abundance of beneficial bacteria, and regulate the balance of microbiota in the gut. These results suggest that FAEb may serve as a potential probiotic to prevent and treat UC.

Overexpression of Staphylococcus aureus efflux pumps is commonly associated with antibiotic resistance, causing conventional antibiotics to be unsuccessful in combating multidrug-resistant bacterial infections. Reducing the activity of the efflux pump is an urgently required to tackle this problem. Here, we found that plantaricin A (PlnA), an antimicrobial peptide derived from Lactobacillus plantarum, had a synergistic effect with ciprofloxacin (CIP), reducing the IC 90 of CIP by eight times. Subsequently, changes in membrane permeability, membrane potential, and reactive oxygen species (ROS) were determined; changes that did not explain the synergistic effect were previously observed. Ethidium bromide intake and efflux experiments showed that PlnA inhibited the function of the efflux pump by binding it and altering the structure of MepA, NorA, and LmrS. Then, a series of PlnA mutants were designed to explore the underlying mechanism; they showed that the charge and foaming of PlnA were the predominant factors affecting the structure of NorA. In a skin wound infection model, PlnA significantly reduced the dose of CIP, relieved inflammation, and promoted wound healing, indicating that PlnA and CIP synergy persisted in vivo. Overall, PlnA reduced the use of CIP for combination therapy, and allowing the continued used of CIP to kill MDR S. aureus. Multidrug-resistant Staphylococcus aureus threatens our life as a tenacious pathogen, which causes infections in hospitals, communities and animal husbandry. Various studies have showed that efflux pump inhibitors (EPIs) have been considered potential therapeutic agents for rejuvenating the activity of antibiotics. Unfortunately, small molecule EPIs exhibit several side effects that limit their use for clinical application. The present study showed a new EPI (plantaricin A) produced by Lactobacillus plantarum, which has low cytotoxicity and haemolysis and powerful inhibitory activity on efflux pumps. Therefore, it helps the design of new EPIs and controls the infection of MDR S. aureus., (© 2022 Society for Applied Microbiology and John Wiley & Sons Ltd.)

Surfactin from Bacillus amyloliquefaciens fmb50 was utilized to treat mice with type 2 diabetes (T2DM) induced by a high-fat diet/streptozotocin (HFD/STZ). Our group's earlier research indicated that surfactin could lower blood glucose and mitigate liver dysfunction to further improve HFD/STZ-induced T2DM through modulating intestinal microbiota. Thus, we further investigated the effects of surfactin on the pancreas and colon in mice with T2DM to elucidate the detailed mechanism. In the present study, mice with HFD/STZ-induced T2DM had their pancreatic and colon inflammation, oxidative stress, and endoplasmic reticulum stress (ERS) reduced when given oral surfactin at a dose of 80 mg/kg body weight. According to further research, surfactin also improved glucose metabolism by activating the phosphatidylinositol kinase (PI3K)/protein kinase B (Akt) signaling pathway, further protecting islets β-cell, promoting insulin secretion, inhibiting glucagon release and mitigating pancreas dysfunction. Additionally, after surfactin treatment, the colon levels of the tight junction proteins Occludin and Claudin-1 of T2DM mice were considerably increased by 130.64% and by 36.40%, respectively. These findings revealed that surfactin not only ameliorated HFD/STZ-induced pancreas inflammation and dysfunction and preserved intestinal barrier dysfunction and gut microbiota homeostasis but also enhanced insulin sensitivity and glucose homeostasis in T2DM mice. Finally, in the further experiment, we were able to demonstrate that early surfactin intervention might delay the development of T2DM caused by HFD/STZ, according to critical biochemical parameters in serum.

Mycotoxins are toxic secondary metabolites produced by fungus including Aspergillus and Fusarium. They can contaminate food and cause major health issues. Bacillomycin D (BD) is a natural antimicrobial lipopeptide generated by Bacillus that has excellent antifungal capabilities, but its high price prevents it from being widely used. Chemically produced and essential oil-based fungicides are also currently the most frequent types. In the study, the effects of combining BD with two types of fungicides on the growth of toxicogenic fungi as well as the generation of deoxynivalenol (DON) and fumonisin B 1 (FB 1 ) were examined. It was discovered that BD was more effective in suppressing molds than the other two types of fungicides, and it could be combined with synthetic or essential oil-based fungicides to provide a synergistic or additive effect. BD 31.25 μg/mL + Thymol (Thy) 7.81 μg/mL and BD 11.45 μg/mL + Cinnamon oil (Cin) 3.90 μg/mL inhibited F. graminearum, respectively. The combination of BD+Thy and BD+Cin at this concentration considerably reduced 60%-80% spore germination, when DON dropped below 300 ng/L. Furthermore, both combinations suppressed F. moniliforme growth and FB 1 synthesis in a dose-dependent manner at lower concentrations. At an action dose of 2 MIC, FB 1 production might be reduced to less than 100 ng/L. Our findings indicated that BD might interact synergistically with various fungicides, suggesting that it could be useful in the field of antifungal and toxicity reduction in food., (Copyright © 2022. Published by Elsevier Ltd.)

Aims: A novel endolysin Salmcide-p1 was developed as a promising candidate of new preservative and a supplement to effective enzyme preparations against gram-negative bacterial contaminations., Methods and Results: Salmcide-p1 was identified by complementing the genomic sequence of a virulent Salmonella phage fmb-p1. Salmcide-p1 of 112 μg ml -1 could quickly kill Salmonella incubated with 100 mmol l -1 EDTA, with no haemolytic activity. Meanwhile, Salmcide-p1 had a high activity of lysing Salmonella cell wall peptidoglycan. At different temperatures (4-75°C), pH (4-11) and NaCl concentration (10-200 mmol l -1 ), the relative activity of Salmcide-p1 was above 60%. At 4°C, the combination of Salmcide-p1 and EDTA-2Na could inhibit the number of Salmonella Typhimurium CMCC 50115 in skim milk to less than 4 log CFU ml -1 by 3 days, and the number of Shigella flexneri CMCC 51571 was lower than 4 log CFU ml -1 by 9 days., Conclusions: Salmcide-p1 had a wide bactericidal activity against gram-negative bacteria and showed a broader anti-Salmonella spectrum than the phage fmb-p1. The combination strategy of Salmcide-p1 and EDTA-2Na could significantly inhibit the growth of gram-negative bacteria inoculated in skim milk., Significance and Impact of the Study: Bacteriophage endolysin as an antibacterial agent is considered to be a new strategy against bacterial contamination., (© 2022 Society for Applied Microbiology.)

Surfactin, an antibacterial lipopeptide produced by different strains of Bacillus subtilis, is a powerful biosurfactant. It also has multiple biological activities including antiviral, anti-mycoplasma and antiprotozoal activities, in addition to the broad-spectrum antimicrobial activities against Gram-positive bacteria, Gram-negative bacteria and fungi. Surfactin may be one of the promising alternatives to antibiotics. Surfactin's chemical structure and physicochemical properties are briefly discussed in this mini-review. Surfactin's antibacterial mechanism is mainly outlined as follows: (1) attacking pathogenic bacteria's cell membrane, causing cell membrane disintegration or osmotic pressure imbalance; (2) inhibiting pathogenic bacteria's protein synthesis, preventing cell reproduction; (3) inhibiting pathogenic bacteria's enzyme activity, affecting normal cell metabolism. This provides basis for the further research and application of surfactin. Finally, the application of surfactin in food and its prospect are summarized in brief., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

As a natural polysaccharide, dextran and its derivatives have gained great attention in the development of delivery systems for pharmaceutical and medical applications. In recent years, numerous dextran-based delivery systems with tailor properties and geometries have been developed, including self-assembled micelles and nanoparticles, nanoemulsions, magnetic nanoparticles, microparticles, and hydrogels. The first part of this review discusses the physicochemical properties of dextran and its various derivatives via chemical modifications, as pertinent to the preparation of delivery systems. Then, the state-of-the-art fabrication strategies of dextran-based delivery systems and their colloidal properties, i.e. particle diameter, surface charge, morphology, as well as release profiles, are highlighted. Lastly, applications of dextran-based drug delivery systems in biomedicine are explicitly summarized with detailed elaborations on their biological efficacy and mechanism of action, including cancer treatment, magnetic resonance imaging, insulin oral delivery, spinal cord injury therapy, and bacterial skin infection treatment., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Pullulanase is a debranching enzyme that cleaves explicitly α-1,6 glycosidic bonds, which is widely used in starch saccharification, production of glucose, maltose, and bioethanol. The thermal-resistant pullulanase is isolated from a variety of microorganisms; however, the lack of industrial production of pullulanase has hindered the transformation of the laboratory to industry. In this study, the expensive maltose syrup and soybean meal powder were replaced with cheap corn starch and corn steep liquor, exhibiting 440 U/mL of pullulanase in shake flasks by changing the C/N value and the total energy of the medium. Subsequently, the cultivation conditions were explored in a 50-L and 50-m 3 bioreactor. In batch culture, the pullulanase activity reached 896 U/mL, while it increased to 1743 U/mL in fed-batch culture by controlling the dissolved oxygen, pH, reducing sugar content, and temperature. Remarkably, the cultivation volume was enlarged to 50 m 3 based on the technical parameters of fed-batch culture. The industrial production of pullulanase was successful, and the activity achieved 1546 U/mL. When the product was stored at room temperature (25 °C) for 6 months, the pullulanase activity was over 90%. The half-lives at 60 and 80 °C were 119.45 h and 51.18 h, respectively, which satisfied the industrial application requirements of pullulanase.

Neomycins are a group of aminoglycoside antibiotics with both clinical and agricultural applications. To elucidate the regulatory mechanism of neomycin biosynthesis, we completed draft genome sequencing of a neomycin producer Streptomyces fradiae CGMCC 4.7387 from marine sediments, and the neomycin biosynthesis gene cluster was identified. Inactivation of the afsA-g gene encoding a γ-butyrolactone (GBL) synthase in S. fradiae CGMCC 4.7387 resulted in a significant decrease of neomycin production. Quantitative RT-PCR analysis revealed that the transcriptional level of neoR and the aphA-neoGH operon were reduced in the afsA-g::aac(3)IV mutant. Interestingly, a conserved binding site of AdpA, a key activator in the GBL regulatory cascade, was discovered upstream of neoR, a putative regulatory gene encoding a protein with an ATPase domain and a tetratricopeptide repeat domain. When neoR was inactivated, the neomycin production was reduced about 40% in comparison with the WT strain. Quantitative RT-PCR analysis revealed that the transcriptional levels of genes in the aphA-neoGH operon were reduced clearly in the neoR::aac(3)IV mutant. Finally, the titers of neomycin were improved considerably by overexpression of afsA-g and neoR in S. fradiae CGMCC 4.7387.

Sweet basil, Ocimum basilicum, is one of the most important and wildly used spices and has been shown to have antioxidant, antibacterial, and anti-diarrheal activities. In this study, high performance liquid chromatographic (HPLC) and flow-injection mass spectrometric (FIMS) fingerprinting techniques were used to differentiate organic and conventional sweet basil leaf samples. Principal component analysis (PCA) of the fingerprints indicated that both HPLC and FIMS fingerprints could effectively detect the chemical differences in the organic and conventional sweet basil leaf samples. This study suggested that the organic basil sample contained greater concentrations of almost all the major compounds than its conventional counterpart on a per same botanical weight basis. The FIMS method was able to rapidly differentiate the organic and conventional sweet basil leaf samples (1min analysis time), whereas the HPLC fingerprints provided more information about the chemical composition of the basil samples with a longer analytical time., (Copyright © 2014 Elsevier Ltd. All rights reserved.)