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Red dragon fruit peel, as a fruit waste, is rich in plant-based nutritional pectins that can be applied as food additives. The present study aims to characterize a novel phosphorylated red dragon fruit peel pectin (PRDFP-P) and to explore its functional activities. The thermal analysis, morphology analysis, antibacterial, antioxidant and antitumor activities of PRDFP-P were evaluated. The results showed that the phosphorylated derivative PRDFP-P had typical phosphate groups. Compared with the native red dragon fruit peel pectin (PRDFP), PRDFP-P possessed superior thermal stability and exhibited significant inhibition effects on Escherichia coli and Staphylococcus aureus. Moreover, the phosphate groups on the derivative PRDFP-P chains remarkably enhanced the scavenging ability of hydroxyl radicals and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. In addition, PRDFP-P showed a significant inhibition effect on growth of human hepatic carcinoma cells (HepG2) and the IC

Patulin (PAT) is a toxic mycotoxin usually contaminated apple juices, which leads to a serious food safety issue in the world. Thiol-compounds are a class of compounds containing the thiol (-SH) group themselves or obtained the -SH group by physical or chemical modification. They have the ability to efficiently remove patulin in apple juices with manifested negligible effects on juice quality. This review investigates the latest development in the removal of patulin using thiol-compounds, including the removal efficiencies and mechanisms of patulin, the factors influencing the removal efficiency of patulin, as well as the toxicities of thiol-compounds and safety of juices after detoxification. This review shows that thiol-compounds are promising materials for the removal or degradation of patulin in the contaminated juices.

In the present work, the effects of combined enzymatic hydrolysis by cellulase and xylanase (CXEH), fed-batch enzymatic hydrolysis (FBEH) operation and kinetics on production of ferulic acid (FA) and p-coumaric acid (pCA) from pretreated corn straws were investigated. The results showed that CXEH could efficiently increase production of FA and pCA. When performed the FBEH operation by feeding 150 mL enzymatic hydrolysis solution (1.5 % enzyme concentration, 5:4 (v/v) ratio of cellulase to xylanase and 2.0 % substrate loading) to 250 mL batch enzymatic hydrolysis solution at 36 h, the maximum production (2178.58 and 2710.17 mg/L) and production rate (590.95 and 727.89 mg/L.h) of FA and pCA were respectively obtained. Moreover, the disruption of fiber tissues, enhancement of crystallinity and accelerated degradation of hemicelluloses and lignocelluloses caused by CXEH contributed to effectively improving production of FA and pCA in corn straws.

A water-soluble polysaccharide from Chaenomeles lagenaria (CLWSP-1) was purified and structurally identified. Then, response surface methodology (RSM) was performed to optimize the hot water extraction (HWE) of CLWSP-1. In addition, the antibacterial activity of CLWSP-1 was also evaluated. The results indicated that the polysaccharide CLWSP-1 mainly contained galacturonic acid, arabinose, and galactose, and its molecular weight was 1.23 × 102 kDa. The optimal HWE for extraction of CLWSP-1 was a ratio of water to solid of 48.9 mL/g, temperature of 91 °C, and an extraction time of 114 min; an ethanol concentration of 81% and a 1.24% concentration of CLWSP-1 were achieved. Moreover, the obtained CLWSP-1 had strong antibacterial activity when exposed to Escherichia coli and Staphylococcus aureus, suggesting that CLWSP-1 may potentially contribute to the development of a natural preservative in the food industry.

A strain with strong antifungal activity, Bacillus subtilis NS-174, was identified and the antifungal compounds were purified and structurally analyzed by high performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS). The effects of the enzymatic hydrolysis and the fermentation strategies on production of the antifungal compounds were also investigated. The results showed that the antifungal compounds were characterized to be C14 and C15 bacillomycin D homologues (C14–15BDs). When 400 mL of the cellulase hydrolysates from the maize straws residues (CHMSRs) was fed into 1.0 L of the batch fermentation broth at 60 h, an output of C14–15BDs (OC14–15BDs) was obtained as 44.84 mg gmaize straws−1. Moreover, the fed-batch fermentation was beneficial for the increase of the transcriptional activities of C14–15BDs synthetase genes by up-regulating expression of comA, sigmaH and spo0A, which caused the elevation of C14–15BDs production. The present work provided an effective solution for lipopeptide production in Bacillus subtilis.

Polyphenols and flavonoids are phytochemicals that have essential roles in human nutrition. In this regard, the contents of polyphenols and flavonoids in Houttuynia cordata Thunb and their antioxidant activities were evaluated in the current study. Two Houttuynia cordata materials with the same chromosome number and chemical type were used to comprehensively assess the contents of total phenols and flavonoids in different parts of H. cordata. These chemical components were extracted by the ultrasonic method. The results showed that the total phenols and antioxidant capacity of different parts of H. cordata were significantly different. The content of polyphenols in roots and stems was low, the antioxidant capacity was weak, the total phenols in flowers and leaves were high, and the antioxidant capacity was strong. Therefore, different parts of H. cordata had different pharmacological and food effects. The whole herb can be used as Chinese herbal medicine, and its young leaves and roots can be used as vegetables. Flavonoids are the main phenolic components, and total phenols are the main components of antioxidant activity. It can explain a very significant positive correlation between total phenols and flavonoids. Therefore, in the further breeding work of H. cordata, the procedure can be simplified by determining one of the above indexes to predict the varieties with high total phenolic and antioxidant activity.

An electrochemical aptasensor based on aptamer was designed for the first time to simultaneously detect Cd

The thermal stability and degradation kinetics of patulin (PAT, 10 μmol/L) in pH 3.5 of phosphoric-citric acid buffer solutions in the absence and presence of cysteine (CYS, 30 μmol/L) were investigated at temperatures ranging from 90 to 150 °C. The zero-, first-, and second-order models and the Weibull model were used to fit the degradation process of patulin. Both the first-order kinetic model and Weibull model better described the degradation of patulin in the presence of cysteine while it was complexed to simulate them in the absence of cysteine with various models at different temperatures based on the correlation coefficients (R2 &gt, 0.90). At the same reaction time, cysteine and temperature significantly affected the degradation efficiency of patulin in highly acidic conditions (p &lt, 0.01). The rate constants (kT) for patulin degradation with cysteine (0.0036–0.3200 μg/L•min) were far more than those of treatments without cysteine (0.0012-0.1614 μg/L•min), and the activation energy (Ea = 43.89 kJ/mol) was far less than that of treatment without cysteine (61.74 kJ/mol). Increasing temperature could obviously improve the degradation efficiency of patulin, regardless of the presence of cysteine. Thus, both cysteine and high temperature decreased the stability of patulin in highly acidic conditions and improved its degradation efficiency, which could be applied to guide the detoxification of patulin by cysteine in the juice processing industry.

The removal of patulin in phosphoric acid buffer solution by cysteine was investigated. Cysteine could effectively decrease the patulin concentration at high acidic condition (pH 3.0–5.0) with the help of high temperature greater than 90 °C. Three removal mechanisms of patulin by cysteine under high acidic and high temperature conditions were deduced. Reaction temperature, pH of reactive media, molar ratio between cysteine and patulin, and reaction time were all the obvious factors influencing the removal efficiency of patulin, and the increase of any one factor could significantly improve the removal efficiency of patulin. The removal process of patulin could be simulated by the zero-order kinetic model, logarithmic model, and pseudo-first-order kinetic model, respectively, and the corresponding correlation coefficients (R2) were all greater than 0.90. Presently, this method can only be applied for the removal of patulin in contaminated water from washing fruits in juice processing industry due to the high treatment temperature more than 120 °C and the long detoxification time greater than 1 h.

Bacillus amyloliquefaciens, a Gram-positive and soil-dwelling bacterium, could produce secondary metabolites that suppress plant pathogens. In this study, we provided the whole genome sequence results of B. amyloliquefaciens fmbJ, which had one circular chromosome of 4 193 344 bp with 4249 genes, 87 tRNA genes, and 27 rRNA genes. In addition, fmbJ was found to contain several gene clusters of antimicrobial lipopeptides (bacillomycin D, surfactin, and fengycin), and bacillomycin D homologues were further comprehensively identified. To clarify the influence of rapC regulating the synthesis of lipopeptide on the yield of bacillomycin D, rapC gene in fmbJ was successfully deleted by the marker-free method. Finally, it was found that the deletion of rapC gene in fmbJ significantly improved bacillomycin D production from 240.7 ± 18.9 to 360.8 ± 30.7 mg/L, attributed to the increased the expression of bacillomycin D synthesis-related genes through enhancing the transcriptional level of comA, comP, and phrC. These results showed that the production of bacillomycin D in B. amyloliquefaciens fmbJ might be regulated by the RapC-PhrC system. The findings are expected to advance further agricultural application of Bacillus spp. as a promising source of natural bioactive compounds.

The present study investigated the stimulation effect of L-glutamine (L-gln) on bacillomycin D biosynthesis of Bacillus subtilis fmbJ and the transcription of the synthetase genes and the signal proteins that related to the biosynthesis of bacillomycin D. It was found that L-gln significantly increased the production of bacillomycin D, in comparison with other amino acids. L-gln significantly enhanced the expression level of bmyA (BYA), bmyB (BYB), bmyC (BYC), the thioesterase gene (TE) and up-regulated DegU, σH and Spo0A, but down-regulated AbrB, therefore the yield of bacillomycin D significantly increased. Furthermore, when conjointly feeding 5 g/L of L-gln and 30 g/L of inulin, the production of bacillomycin D was up to 1.93 g/L.

In this study, deoxynivalenol (DON) in aqueous solution was exposed to gaseous ozone for periods ranging from 0 to 20 min. The degradation efficiency and cytotoxicity of DON were investigated after being treated by ozone. The results showed that DON was rapidly degraded from 10.76 &plusmn, 0.09 mg/L to 0.22 &plusmn, 0.04 mg/L within 15 min (P &lt, 0.05), representing a reduction of 97.95%, and no DON was detected after being exposed to 14.50 mg/L of ozone at a flow rate of 80 mL/min for 20 min. The degradation of DON depended on the ozone exposure time, and followed the first-order kinetic model (R2 = 0.9972). Human hepatic carcinoma (HepG2) and Henrietta Lacks (Hela) cells were used to evaluate the cytotoxicity of DON treated by ozone using the 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The half-maximal inhibitory concentrations (IC50) values of DON on HepG2 and Hela cells were 2.10 and 1.33 mg/L after 48 h of exposure, respectively, and showed a dose-dependent manner. The cell vitalities of HepG2 and Hela cells on DON were both evidently improved after being exposed to ozone for 15 min, and there were no significant differences between the negative control and that treated at 20 min of ozone exposure. Gaseous ozone can potentially be used as a new method to detoxify DON in agricultural products.

The inhibition effects of bacillomycin D on the growth of Aspergillus ochraceus and the production of ochratoxin A (OTA) in food samples were investigated. The mycelia growth and sporulation were completely inhibited by 30 μg/mL of bacillomycin D. Microscopic morphological changes such as the distortion of hyphae and the disruption of spores at 20 μg/mL of bacillomycin D were significantly observed. The use of bacillomycin D resulted in cell damage, nucleic acids and proteins divulge, and more production of reactive oxygen species (ROS), and all these factors actively contributed to the promotion of apoptosis of A. ochraceus . In addition, 90 μg/g of bacillomycin D completely inhibited the growth of A. ochraceus and the production of OTA in food samples. Our results suggested that bacillomycin D showed a significant antifungal activity against A. ochraceus that could be used as a potential natural antimicrobial to control food contamination and ensure food safety.

The present study investigated the production of xylooligosaccharides (XOS) from the xylans extracted from maize straws (XMSs) using the fed-batch enzymatic hydrolysis strategy (FBEH). When fed 300 mL of the fresh XMSs with 2 % of the substrate loading and 12 U/g of the enzyme activity at the enzymatic hydrolysis time of 7 h, the yield of XOS was obtained to be 0.67 g/g of XMSs. Characterization analysis indicated that XOS contained typical molecular groups and side chains of oligosaccharides and was mainly composed of xylobiose, xylotriose and xylose. Furthermore, XOS exhibited strong antioxidant capacity in vitro and had a significant inhibition effect on HepG2 cells, indicating that XOS might be potentially used as natural antioxidants and anticancer additives in food or pharmaceutical industry.

Aims To explore the influence of carbohydrates on the production of fengycin by Bacillus amyloliquefaciens fmb-60. Methods and Results Fermentation and gene expression levels were examined following culture supplementation with fructose, arabinose and sorbitol. Compared with other carbohydrates, fructose most efficiently increased the concentration of the essential component amino acids for fengycin synthesis in the cell. The maximum production of fengycin was found to be 392.87 mg l-1, increased by 76% in fed-batch fermentation. Furthermore, fructose enhanced the biosynthesis of fengycin by increasing the expression of fengycin synthetase genes (fenA, fenB, fenC, fenD, fenE and fenTE) and regulatory genes (comA, degU, degQ and sigma H). Conclusion Fructose is important for fengycin production in B. amyloliquefaciens fmb-60, and it could enhance fengycin biosynthesis by raising the expression of the fengycin synthetase genes and upregulating signal factors. Significance and Impact of the Study The results identify regulatory mechanisms involved in fengycin biosynthesis and provide an effective method to enhance production of fengycin. This article is protected by copyright. All rights reserved.

The effect of inulin on the production of bacillomycin D and the levels of mRNA of bacillomycin D synthetase genes: bmyA (BYA), bmyB (BYB), bmyC (BYC), the thioesterase gene (TE) and regulating genes: AbrB, ComA, DegU, PhrC, SigmaH and Spo0A in Bacillus subtilis fmbJ were investigated. The production of bacillomycin D was enhanced with the increase of biomass concentration. The maximum production and productivity of bacillomycin D were found to be 1227.49 mg/L and 10.23 mg/L h. Inulin significantly improved the expression of bacillomycin D synthetase genes: bmyA (BYA), bmyB (BYB), bmyC (BYC) and the thioesterase gene (TE). Also, inulin up-regulated ComA, DegU, SigmaH and Spo0A and therefore promoted the high production of bacillomycin D. Our results provided a practical approach for efficient production of bacillomycin D and a meaningful explanation for regulatory mechanism of bacillomycin D biosynthesis.

Liver allografts can be spontaneously accepted across an MHC class I disparity, the mechanism of which is still not known. Since the liver has a large amount of immature dendritic cells, these elements may contribute to transplant acceptance. However, the reason why liver dendritic cells are immature status is unknown. In this study, bone marrow-derived dendritic cell progenitors were cocultured with liver stellate cells, which produce the immunosuppressive cytokines IL-10 and TGF-beta. The results revealed that dendritic cells cocultured with liver stellate cells express low levels of costimulatory molecules with decreased allostimulatory capacity. Addition of anti-IL-10 antibody to the culture media to neutralize IL-10 effects reversed the allostimulatory function of dendritic cells cocultured with stellate cells. In conclusion, liver dendritic cells are conditioned by stellate cells to maintain an immature status, which may contribute to the low immunity of liver. One of the mechanisms that stellate cells may influence dendritic cells is through IL-10.