Occurrence of ochratoxin A in Sichuan bacon from different geographical regions and characterization and biocontrol of ochratoxigenic Aspergillus westerdijkiae strain 21G2-1A.

Sichuan bacon represents the most prevalent dry-cured meat product across Southwest China, but it is vulnerable to fungal spoilage. In the present study, a total of 47 Sichuan bacons were obtained from different regions of the Sichuan Province and analyzed for the presence of ochratoxin A (OTA), yielding a positive rate of 23.4 % (11/47). All the observed OTA concentrations exceeded the maximum admissible dose in meat products (1 µg/kg) established by some EU countries, with the highest OTA concentration being 250.75 µg/kg, which raises a food safety concern and reveals the need for a standardized scientific processing protocol. Then, an OTA-producing fungus named 21G2-1A was isolated from positive samples and found to be Aspergillus westerdijkiae. Further characterization suggested a positive correlation between fungal growth and OTA production. The optimal temperature for the former was 25 °C, while it was 20 °C for the latter. Although the A. westerdijkiae strain 21G2-1A demonstrated greater mycelium growth in the presence of NaCl, OTA production was significantly dismissed when the salinity was greater than 5 %. Four lactic acid bacteria (LAB) were screened out as antagonists against the ochratoxigenic fungus. In vitro evaluation of the antagonists revealed that live cells inhibited fungal growth, and adsorption also contributed to OTA removal at different levels. This study sheds some light on OTA control in Sichuan bacon through a biological approach.

Insight into a natural novel histidine decarboxylase gene deletion in Enterobacter hormaechei RH3 from traditional Sichuan-style sausage.

Histamine (HIS) is primarily formed from decarboxylated histidine by certain bacteria with histidine decarboxylase (hdc) activity and is the most toxic biogenic amine. Hdc, which is encoded by the hdc gene, serves as a key enzyme that controls HIS production in bacteria. In this paper, we characterized the changes in microbial and biogenic amines content of traditional Sichuan-style sausage before and after storage and demonstrated that Enterobacteriaceae play an important role in the formation of HIS. To screen for Enterobacteriaceae with high levels of HIS production, we isolated strain RH3 which has a HIS production of 2.27 mg/mL from sausages stored at 37°C for 180 days, using selective media and high-performance liquid chromatography. The strain RH3 can produce a high level of HIS after 28 h of fermentation with a significant hysteresis. Analysis of the physicochemical factors revealed that RH3 still retained its ability to partially produce HIS in extreme environments with pH 3.5 and 10.0. In addition, RH3 exhibited excellent salt tolerance (6.0% NaCl and 1.0% NaNO2 ). Subsequently, RH3 was confirmed as Enterobacter hormaechei with hdc gene deletion by PCR, western blot, and whole-genome sequencing analysis. Furthermore, RH3 exhibited pathogenicity rate of 75.60% toward the organism, indicating that it was not a food-grade safe strain, and demonstrated a high level of conservation in intraspecific evolution. The results of this experiment provide a new reference for studying the mechanism of HIS formation in microorganisms. PRACTICAL APPLICATION: This study provides a new direction for investigating the mechanism of histamine (HIS) formation by microorganisms and provides new insights for further controlling HIS levels in meat products. Further research can control the key enzymes that form HIS to control HIS levels in food.

Transcriptome profiles and chromatin states in mouse androgenetic haploid embryonic stem cells.

Haploid embryonic stem cells (haESCs) are derived from the inner cell mass of the haploid blastocyst, containing only one set of chromosomes. Extensive and accurate chromatin remodelling occurs during haESC derivation, but the intrinsic transcriptome profiles and chromatin structure of haESCs have not been fully explored. We profiled the transcriptomes, nucleosome positioning, and key histone modifications of four mouse haESC lines, and compared these profiles with those of other closely-related stem cell lines, MII oocytes, round spermatids, sperm, and mouse embryonic fibroblasts. haESCs had transcriptome profiles closer to those of naïve pluripotent stem cells. Consistent with the one X chromosome in haESCs, Xist was repressed, indicating no X chromosome inactivation. haESCs and ESCs shared a similar global chromatin structure. However, a nucleosome depletion region was identified in 2056 promoters in ESCs, which was absent in haESCs. Furthermore, three characteristic spatial relationships were formed between transcription factor motifs and nucleosomes in both haESCs and ESCs, specifically in the linker region, on the nucleosome central surface, and nucleosome borders. Furthermore, the chromatin state of 4259 enhancers was off in haESCs but active in ESCs. Functional annotation of these enhancers revealed enrichment in regulation of the cell cycle, a predominantly reported mechanism of haESC self-diploidization. Notably, the transcriptome profiles and chromatin structure of haESCs were highly preserved during passaging but different from those of differentiated cell types.

Blueberry extract alleviated lipopolysaccharide-induced inflammation responses in mice through activating the FXR/TGR5 signaling pathway and regulating gut microbiota.

BACKGROUND: Blueberry extract (BE) is rich in phenols, especially anthocyanins. Anthocyanins regulate the inflammatory response in mice and may be related to gut microbiota and bile acid receptors. The aim of the present study was to explore the effects of BE on the inflammatory response by regulating gut microbiota and bile acid receptors in mice administered Escherichia coli lipopolysaccharide (LPS). METHOD: Thirty male KM mice were randomly divided into three groups: CON (control diet) group; LPS (LPS stimulation) group; and LPS + BE (LPS stimulation, 5% BE intervention) group. RESULTS: our results showed that, compared with the LPS group, the addition of BE decreased the level of inflammatory factors in serum and tissues, inhibited the TLR4/MyD88 signaling pathway, protected the intestinal barrier and activated FXR/TGR5, which was related to gut microbiota (especially Akkermansia). The active component (e.g., cyanidin 3-O-glucoside, C3G) in BE may be an important factor in regulating gut microbiota. CONCLUSION: BE alleviated the inflammatory response mainly by activating bile acid receptor expression and regulating the gut microbiota; this effect may be related to the composition of bioactive substances in BE. © 2023 Society of Chemical Industry.

Use of Heat-Shock and Edible Coating to Improve the Postharvest Preservation of Blueberries.

The quality of blueberry fruit is easily altered after harvest. We investigated the regulatory mechanism of heat-shock (postharvest treatment) and edible coating (preharvest treatment) on the post-harvest physiological quality of blueberry from the perspective of physiological, biochemical and organoleptic characteristics. In our research, the optimal TKL concentration and the appropriate range of heat-shock temperatures were first screened based on actual application results, and then a combination of heat-shock temperature and TKL coating with significant differences in preservation effects was selected to investigate the effects of different heat-shock temperatures and TKL60 composite coating on post-harvest quality and volatile compound concentration of blueberries under refrigerated conditions. Our results showed that TKL with 60 mg/L thymol can retard the development of the degree of membrane lipid peroxidation and effectively reduce the incidence of fruit decay and the severity of blueberries infected with major pathogens at 25 °C. Meanwhile, heat-shock treatments were effective in maintaining the quality of blueberries, with a certain advantage from 45 °C to 65 °C after 8 d of storage at ambient temperature, but these treated groups were slightly inferior to TKL60 groups for fresh-keeping effect. Remarkably, the combination of heat-shock treatment and edible coating application could extend the shelf life of blueberries by 7-14 d compared to the results obtained with coating alone under low temperature storage. Specifically, heat treatment at 45 °C for 60 min after TKL60 coating (HT2) retarded the decrease in the levels of ascorbic acid, total anthocyanin, total acid and soluble solids. Gas chromatography-mass spectrometry hierarchical clustering analysis showed that this treatment also improved the aroma of the fruit, which maintained a certain similarity with that of fresh blueberries after 14 d. Principal component analysis (PCA) of the results of the evaluations carried out using an electronic nose (E-nose) and electronic tongue (E-tongue) showed that blueberries of the HT2 treated group did not show a large placement change of the PC1 distribution area from that of the fresh and blank control group. Accordingly, the combination of coating with heat-shock treatment can effectively improve the post-harvest quality and aroma compound concentration of blueberries, showing good application potential in storage and preservation of fresh fruits such as blueberries.

Thymol Edible Coating Controls Postharvest Anthracnose by Regulating the Synthesis Pathway of Okra Lignin.

Okra has received extensive attention due to its high nutritional value and remarkable functional characteristics, but postharvest diseases have severely limited its application. It is important to further explore the methods and potential methods to control the postharvest diseases of okra. In this study, Colletotrichum fioriniae is the major pathogen that causes okra anthracnose, which can be isolated from naturally decaying okra. The pathogenicity of C. fioriniae against okra was preliminarily verified, and the related biological characteristics were explored. At the same time, an observational study was conducted to investigate the in vitro antifungal effect of thymol edible coating (TKL) on C. fioriniae. After culturing at 28 °C for 5 days, it was found that TKL showed an obvious growth inhibition effect on C. fioriniae. The concentration for 50% of the maximal effect was 95.10 mg/L, and the minimum inhibitory concentration was 1000 mg/L. In addition, it was found that thymol edible coating with a thymol concentration of 100 mg/L (TKL100) may cause different degrees of damage to the cell membrane, cell wall, and metabolism of C. fioriniae, thereby inhibiting the growth of hyphae and causing hyphal rupture. Refer to the results of the in vitro bacteriostatic experiment. Furthermore, the okra was sprayed with TKL100. It was found that the TKL100 coating could significantly inhibit the infection of C. fioriniae to okra, reduce the rate of brown spots and fold on the okra surface, and inhibit mycelium growth. In addition, the contents of total phenols and flavonoids of okra treated with TKL100 were higher than those of the control group. Meanwhile, the activities of phenylalaninammo-nialyase, cinnamic acid-4-hydroxylase, and 4-coumarate-CoA ligase in the lignin synthesis pathway were generally increased, especially after 6 days in a 28 °C incubator. The lignin content of TKL-W was the highest, reaching 65.62 ± 0.68 mg/g, which was 2.24 times of that of CK-W. Therefore, TKL may promote the synthesis of total phenols and flavonoids in okra, then stimulate the activity of key enzymes in the lignin synthesis pathway, and finally regulate the synthesis of lignin in okra. Thus, TKL could have a certain controlling effect on okra anthracnose.

In vitro simulated digestion of and microbial characteristics in colonic fermentation of polysaccharides from four varieties of Tibetan tea.

Polysaccharides as a functional prebiotic have numerous activities such as regulating intestinal microorganisms and polysaccharide is one of the functional active components in tea has been known. In this study, we aimed to investigate the physicochemical characteristics of polysaccharides from four kinds of Tibetan teas at simulated digestion stages and the effect on the microbiota of fecal fermentation stages in vitro. The results revealed that Tibetan tea polysaccharides were partially digested during digestion. Additionally, during in vitro fecal microbial fermentation, Tibetan tea polysaccharides can promote the growth of some beneficial bacteria such as Bifidobacterium, Prevotella and Phascolarctobacterium to change the composition of intestinal microorganisms and promote the production of short-chain fatty acids (SCFAs). Finally, a strong correlation was found between the production of SCFAs and microorganisms including Bacteroides, Bifidobacterium and Lachnoclostridium. These results suggest that Tibetan tea polysaccharides could be developed as a prebiotic to regulate human gut microbiota.

Transcriptomic analysis reveals peripheral pathway in 3-phenoxybenzoic acid degradation by Aspergillus oryzae M-4.

As a major intermediate metabolite of synthetic pyrethroids, the occurrence of 3-phenoxybenzoic acid hinders the decomposition of the parent pesticide and poses uncertain risks to environmental ecology and living organisms. Strain Aspergillus oryzae M-4 was previously reported to degrade 3-PBA and several substances were identified as downstream transformation products (TPs). But the mechanism underlying the cleavage of ether bond remains largely unclear. Here, we attempted to address such concern through identifying the peripheral TPs and analyzing transcriptomics, coupled with serial batch degradation experiments. Analysis results of chromatographic/mass spectrometry suggested that 3-PBA underwent twice hydroxylation, to yield mono- and dihydroxylated 3-PBA successively. In parallel, a mutual transformation between 3-PBA and 3-phenoxybenzyl alcohol (3-PBOH) also existed. The proposal of peripheral pathway represents an important advance towards fully understanding the whole 3-PBA metabolism in M-4. A specific altered metabolization was found for the first time, that is, resting cells of M-4 skipped the reduction step and initiate hydroxylation directly, by comparison with growing cells. Transcriptome analysis indicated that 3-PBA induced the up-regulation of genes related to energy investment, oxidative stress response, membrane transport and DNA repair. In-depth functional interpretation of differential expression genes suggested that the generation 3-PBOH and hydroxylated 3-PBA may be due to the participation of flavin-dependent monooxygenases (FMOs) and cytochrome P450 (CYP450), respectively. This study provides new insight to reveal the biodegradation mechanism of 3-PBA by A. oryzae M-4.

An updated review of functional properties, debittering methods, and applications of soybean functional peptides.

Soybean functional peptides (SFPs) are obtained via the hydrolysis of soybean protein into polypeptides, oligopeptides, and a small amount of amino acids. They have nutritional value and a variety of functional properties, including regulating blood lipids, lowering blood pressure, anti-diabetes, anti-oxidant, preventing COVID-19, etc. SFPs have potential application prospects in food processing, functional food development, clinical medicine, infant milk powder, special medical formulations, among others. However, bitter peptides containing relatively more hydrophobic amino acids can be formed during the production of SFPs, seriously restricting the application of SFPs. High-quality confirmatory human trials are needed to determine effective doses, potential risks, and mechanisms of action, especially as dietary supplements and special medical formulations. Therefore, the physiological activities and potential risks of soybean polypeptides are summarized, and the existing debitterness technologies and their applicability are reviewed. The technical challenges and research areas to be addressed in optimizing debittering process parameters and improving the applicability of SFPs are discussed, including integrating various technologies to obtain higher quality functional peptides, which will facilitate further exploration of physiological mechanism, metabolic pathway, tolerance, bioavailability, and potential hazards of SFPs. This review can help promote the value of SFPs and the development of the soybean industry.

Effects of thymol concentration on postharvest diseases and quality of blueberry fruit.

In this study, we compared the incidence of postharvest disease and the storage potential of blueberry fruit treated with thymol (inoculated with Aspergillus niger) with those in the control fruit during storage for 42 d at 2 °C. Treatment with 10-30 mg/L thymol was found to be more effective than treatment with higher thymol concentrations of 40-50 mg/L in terms of controlling Aspergillus niger-induced decay. In the thymol-treated blueberry fruit peel, the activities of the disease resistance-related enzymes were significantly enhanced. Furthermore, the 20 mg/L thymol-treated blueberry fruit retained the highest firmness, total soluble solids content, and acceptability score, and it also maintained an unimpaired cell wall structure of pericarp quality. Thus, low-dose thymol-treatment could be a suitable biocontrol agent for controlling postharvest disease and prolonging the storage life of blueberry fruit.

Seasonal dynamics of microbiota and physicochemical indices in the industrial-scale fermentation of Sichuan Baoning vinegar.

We investigated the impact of seasons of the year on microbiota and physicochemical indices in industrial-scale fermentation of Sichuan Baoning vinegar. Illumina HiSeq sequencing results showed significant differences (P < 0.05) between the microbiomes of vinegar Pei in every-two seasons, except for bacterial communities between summer and autumn. Total acid, reducing sugar, starch, and alcohol contents of vinegar Pei from the same sampling day of each season were measurably different. Although total acid content in vinegar Pei was similar at the end of fermentation (P > 0.05), the increase in total acidity was highest in the autumn. Acetic acid content in raw vinegar was highest in the autumn (3472.42 mg/100 mL), and lowest in the summer (2304.01 mg/100 mL). This study provides a theoretical basis for the production of Sichuan bran vinegar with consistent quality and provides insights into the quality control of traditional fermented foods.

Efficacy and Mechanism of Thymol/KGM/LG Edible Coating Solution on Inhibition of Mucor circinelloides Isolated From Okra.

With the increasing demand and quality requirement for the natural nutritious food in modern society, okra has attracted much attention because of its high nutritional value and remarkable functionality. However, the occurrence of postharvest diseases of fresh okra severely limited the application and the value of okra. Therefore, in this study, the dominant pathogens causing postharvest diseases such as soft rot were isolated from naturally decaying okra. It was identified as Mucor circinelloides by its morphological characteristics and standard internal transcribed spacer ribosomal DNA sequence. Furthermore, the biological characteristics of M. circinelloides were studied, and the inhibitory effect of thymol/KGM/LG (TKL) edible coating solution on M. circinelloides and its possible mechanism was discussed. In addition, TKL edible coating solution had a dose-dependent inhibitory effect on M. circinelloides, with a 50% inhibitory concentration (EC50) of 113.55 mg/L. The TKL edible coating solution at 960 mg/L of thymol completely inhibited mycelial growth and spore germination of M. circinelloides. The results showed that the best carbon source of M. circinelloides was maltose, the best nitrogen source was beef extract and potassium nitrate, the best pH was 6, the best temperature was 28°C, the best NaCl concentration was 0.5%, and the light was conducive to the growth of M. circinelloides. It was also observed by scanning electron microscope (SEM) that TKL was more likely to destroy the cell wall integrity of M. circinelloides, inhibit spore morphology and change mycelium structure. Meanwhile, the activity of chitinase (CHI), an enzyme related to cell wall synthesis of M. circinelloides, was significantly decreased after being treated by TKL with thymol at 100 mg/L (TKL100). The content of Malondialdehyde (MDA) in M. circinelloides decreased significantly from 12 h to 48 h, which may cause oxidative damage to the cell membrane. The activity polygalacturonase (PG), pectin methylgalacturonase (PMG), and cellulase (Cx) of M. circinelloides decreased significantly. Therefore, the results showed that TKL had a good bacteriostatic effect on okra soft rot pathogen, and the main bacteriostatic mechanism might be the damage of cell membrane, degradation of the cell wall, inhibition of metabolic activities, and reduction of metabolites, which is helpful to further understand the inhibitory effect of TKL on okra soft rot pathogen and its mechanism.

Adsorption Behavior of 3-phenoxybenzoic Acid by Lactobacillus Plantarum and Its Potential Application in Simulated Digestive Juices.

3-PBA is a major degradation intermediate of pyrethroids. Its widespread existence in the environment poses a severe threat to the ecosystem and human health. This study evaluated the adsorption capacity of L. plantarum RS20 toward 3-PBA. Batch adsorption experiments indicated that the optimal adsorption conditions were a temperature of 37 °C and initial pH of 6.0-8.0, under which the removal rate was positively correlated with the cell concentration. In addition, there was no link between the incubation time and adsorption rate. The kinetic study showed that the adsorption process fitted well with the pseudo-second-order model, and the adsorption isotherms could be described by both Langmuir and Freundlich equations. Heat and acid treatments showed that the ability of strain RS20 in removing 3-PBA was independent of microbial vitality. Indeed, it was involved with chemisorption and physisorption via the cell walls. The cell walls made the highest contribution to 3-PBA removal, according to the adsorption experiments using different cellular components. This finding was further reconfirmed by SEM. FTIR spectroscopy analysis indicated that carboxyl, hydroxyl, amino groups, and -C-N were the functional sites for the binding of 3-PBA. The co-culture experiments showed that the adsorption of strain RS20 enhanced the degradation of 3-PBA by strain SC-1. Strain RS20 could also survive and effectively remove 3-PBA in simulated digestive juices. Collectively, strain RS20 could be employed as a biological detoxification agent for humans and animals by eliminating 3-PBA from foods, feeds, and the digestive tract in the future.

A deep learning method for the recognition of solar radio burst spectrum.

Solar radiation is the excitation source that affects the weather in the atmosphere of the earth, and some solar activities such as flares and coronal mass ejections are often accompanied by radio bursts. The spectrum of solar radio bursts is helpful for astronomers to explore the mechanism of radio bursts. With the development and progress of solar radio spectrum observation methods, the observation of the Sun can be done at almost all times of day. How to quickly and automatically identify the small proportion of burst data from the huge corpus of observation data has become an important research direction. The innovation of this study is to enhance the original radio spectrum dataset with unbalanced sample distribution, and a neural network model for solar radio spectrum image classification is proposed on this basis. This hybrid structure of joint convolution and a memory unit overcomes the shortcoming of the traditional convolution or memory model, which can only extract one-sided features of an image. By extracting the frequency structure features and time-series features at the same time, the sensitivity to the small features of the spectrum image can be enhanced. Based on the data of the Solar Broadband Radio Spectrometer (SBRS) in China, the proposed network model can improve the average classification accuracy of the spectrum image to 98.73%, which will be helpful for related astronomical research.

Infrared spectrometric biomarkers for ulcerative colitis screening using human serum samples.

This study uses infrared spectrometry coupled with data analysis techniques to understand colitis-induced alterations in the molecular components of serum samples. Using samples from 18 ulcerative colitis patients and 28 healthy volunteers, we assessed features such as absorbance values at wavenumbers of 1033 and 1076 cm-1 , and the ratios at 1121 versus 1020 cm-1 and 1629 versus 1737 cm-1 . Through the deconvolution of the amide I band, protein secondary structure analysis was performed. Colitis-induced alterations are reflected as fluctuations in the vibrational modes, and are used to identify associated spectral signatures. The results of the study show statistically significant differences in five identifying spectral signatures. Among them, the sensitivity and specificity of the spectral signature, I1121 /I1020 , were 100% and 86%, respectively. These findings resemble our earlier proof-of-concept investigations in mouse models and provide preliminary evidence that this could be a reliable diagnostic test for human patients.

Effectiveness of Maitland and Mulligan mobilization methods for adults with knee osteoarthritis: A systematic review and meta-analysis.

BACKGROUND: As a serious global problem, knee osteoarthritis (KOA) often leads to pain and disability. Manual therapy is widely used as a kind of physical treatment for KOA. AIM: To explore further the efficacy of Maitland and Mulligan mobilization methods for adults with KOA. METHODS: We searched PubMed, the Cochrane Library, EMbase, Web of Science and Google Scholar from inception to September 20, 2020 to collect studies comparing Maitland and Mulligan mobilization methods in adults with KOA. The quality of the studies was assessed using the Physiotherapy Evidence Database Scale for randomized controlled trials. Data analyses were performed using Review Manager 5.0 software. RESULTS: A total of 341 articles were screened from five electronic databases (PubMed, the Cochrane Library, EMbase, Web of Science and Google Scholar) after excluding duplicates. Ultimately, eight trials involving 471 subjects were included in present systematic review and meta-analysis. The mean PEDro scale score was 6.6. Mulligan mobilization was more effective in alleviating pain [standardized mean difference (SMD) = 0.60; 95% confidence interval (CI): 0.17 to 1.03, P = 0.007; I 2 = 60%, P = 0.020) and improving Western Ontario and McMaster Universities function score (SMD = 7.41; 95%CI: 2.36 to 12.47, P = 0.004; I 2 = 92%, P = 0.000). There was no difference in the effect of the two kinds of mobilization on improving the range of motion (SMD = 9.63; 95%CI: -1.23 to 20.48, P = 0.080; I 2 = 97%, P = 0.000). CONCLUSION: Mulligan mobilization technique is a promising intervention in alleviating pain and improving function score in KOA patients.

Confidence intervals for the Youden index and its optimal cut-off point in the presence of covariates.

In medical diagnostic studies, the Youden index is a summary measure widely used in the evaluation of the diagnostic accuracy of a medical test. When covariates are not considered, the diagnostic accuracy of the test can be biased or misleading. By incorporating information from covariates using linear regression models, we propose generalized confidence intervals for the covariate-adjusted Youden index and its optimal cut-off point. Furthermore, under heteroscedastic regression models, we propose various confidence intervals for the covariate-adjusted Youden index and its optimal cut-off point. Extensive simulation studies are conducted to evaluate the finite sample performance of various confidence intervals for the Youden index and its optimal cut-off point in the presence of covariates. To illustrate the application of our recommended methods, we apply the methods to a dataset on postprandial blood glucose measurements.

Optimizing infrared spectral discrimination to enhance disease diagnostics: monitoring the signatures of inflammatory bowel diseases with anti-TNFα therapy.

This study presents an application of infrared spectroscopy of sera for monitoring the efficacy of anti-TNFα therapy for inflammatory bowel diseases. Understanding the therapeutic response includes the analysis of absorption bands representing constituent molecules. Interleukin-10 knockout mouse model of the diseases with anti-TNFα treatment was used. The discrimination potential is optimized by analyzing data with curve fitting. It shows; antibody therapy markedly ameliorated the disease, concurring with earlier mucosal immunology and pathophysiologic studies. This technique may thus also be useful for the evaluation of mucosal healing or other therapeutic modalities of gastrointestinal tract diseases keeping the endoscopic tests as confirmatory.

Structural characterization of a polysaccharide from Suillellus luridus and its antidiabetic activity via Nrf2/HO-1 and NF-κB pathways.

A heteropolysaccharide designated SLPC-1S with the Mw of 9.4 kDa was purified from the caps of Suillellus luridus. Monosaccharide composition analysis revealed that SLPC-1S was composed of galactose, glucose, arabinose and mannose in a molar ratio of 44.9:27.6:14.7:12.8. Structural characterization indicated that SLPC-1S had a backbone principally composed of 1,3 linked α-D-Galp, 1,3 linked ß-D-Glcp and 1,6 linked ß-D-Glcp with the branches mainly composed of 1,3 linked ß-D-Glcp, 1,3 linked α-L-Arap, 1,3 linked α-D-Manp and T-linked α-D-Galp. Furthermore, SLPC-1S exhibited excellent antidiabetic activities in the streptozotocin-induced diabetic mice. Protein expression and mRNA levels in NF-kB and Nrf2/HO-1 signaling pathways were detected by western blots and real-time polymerase chain reaction (RT-PCR), respectively. The results strongly proved that SLPC-1S can be treated as a potential agent for preventing and treating diabetes via regulating Nrf2-mediated oxidative stress and NF-κB-mediated inflammatory responses.

Isolation and Characterization of a Novel Diethylstilbestrol-Degrading Bacillus subtilis JF and Biochemical Degradation Metabolite Analysis.

Diethylstilbestrol (DES) can adversely affect the immune system of developing fetuses or even elicit toxic responses such as nerve toxicity and genotoxicity in human beings, thereby warranting methods to remove DES from the environments. The present study characterized a novel DES-degrading Bacillus subtilis JF and analyzed the degradation metabolites. The strain was collected at the China General Microbiological Culture Collection Center (Collection number: CGMCC 7950). The environmental effects, such as DES concentrations, pH levels, and temperature, on the strain's degradation ability were tested. Degradation metabolites of DES by strain JF were analyzed via high performance liquid chromatography (HPLC) and liquid-chromatography time of flight mass spectrometry (LC-TOF-MS). Results indicated that B. subtilis JF can effectively degrade DES within a concentration of 25-200 mg/L. Increasing pH levels (pH > 7) are reported to increase the degradation rate of DES by the strain. The optimal temperature for strain JF to degrade DES was identified as 45°C. In this study, 4, 4'-hexene estrogen quinones (DESQ) and DES-4-semiquinone were speculated as two degradation metabolites of DES, and both can be completely degraded by strain JF. A slight reduction of DES in the blank system [DES cultured in Luria-Bertani (LB) medium without strain JF] was observed in this study. The reduction trend in the blank system only occurred during the first few days (about 4 days) and was considerably lesser than the decomposition and transformation effect of DES via strain JF. Furthermore, the metabolite DESQ could not be further decomposed in blank LB medium without strain JF. All the results demonstrate that complete degradation of DES in the fermentation broth occurs due to the function of strain JF rather than organic decomposition. In conclusion, the high efficiency of degradation and the potential to degrade DES completely indicates that strain JF has potential for the bioremediation of DES-contaminated environments (soil, river, and so on) and fermented foods.