Quantum spin driven Yu-Shiba-Rusinov multiplets and fermion-parity-preserving phase transition in K3C60.

Magnetic impurities in superconductors are of increasing interest due to emergent Yu-Shiba-Rusinov (YSR) states and Majorana zero modes for fault-tolerant quantum computation. However, a direct relationship between the YSR multiple states and magnetic anisotropy splitting of quantum impurity spins remains poorly characterized. By using scanning tunneling microscopy, we systematically resolve individual transition-metal (Fe, Cr, and Ni) impurities induced YSR multiplets as well as their Zeeman effects in the K3C60 superconductor. The YSR multiplets show identical d orbital-like wave functions that are symmetry-mismatched to the threefold K3C60(1 1 1) host surface, breaking point-group symmetries of the spatial distribution of YSR bound states in real space. Remarkably, we identify an unprecedented fermion-parity-preserving quantum phase transition between ground states with opposite signs of the uniaxial magnetic anisotropy that can be manipulated by an external magnetic field. These findings can be readily understood in terms of anisotropy splitting of quantum impurity spins, and thus elucidate the intricate interplay between the magnetic anisotropy and YSR multiplets.

Integrated analysis of transcriptome and metabolome revealed biological basis of sows from estrus to lactation.

Characterization of molecular mechanisms underlying pregnancy development of sows is important for the genetic improvement of pig breeding traits, and also provides resources for biomedical research on human pregnancy diseases. However, the transcriptome and metabolome across multiple developmental stages of sow pregnancy were still lacking. In this study, we obtained 84 distinct RNA sequencing and 42 metabolome datasets of pig blood across six development stages from estrus to lactation. We confirmed the initial sequence and exonic structural features, stage-specific molecules, expression or accumulation pattern of molecules, the regulatory mechanism of transcriptome and metabolome, and important pregnancy-related metabolites both in pigs and humans. In conclusion, we proposed the key differences among the stages of sows from estrus to lactation in RNAs and metabolites and put forward key markers. These data results were expected to provide essential resources for pig breeding and biomedical research on human pregnancy disease.

Metabolomics and lipidomics profiles related to intramuscular fat content and flavor precursors between Laiwu and Yorkshire pigs.

Chinese indigenous pig breeds have higher intramuscular fat content (IMF) and better meat quality than Western commercial pigs. The differential metabolites and lipids in the skeletal muscle associated with IMF contents and meat flavor in Laiwu and Yorkshire pigs were investigated in this study. As a result, 113 differential metabolites and 54 differential lipids were discovered. Lipidomics revealed that the Laiwu pig had a fast lipid droplet formation and contained more triglyceride than the Yorkshire pig, which was corresponded to its high IMF contents. Both the lipidomics and metabolomics results indicated that the Laiwu pig had a higher mitochondrial content and aerobic respiration, due to its larger percentage of oxidative fibers. In addition, differential metabolites, such as oxoglutaric acid, fumarate, and l-aspartate, were thought to be important flavor precursors contributing to the Laiwu pig's improved pork taste.

Copy Number Variations Contribute to Intramuscular Fat Content Differences by Affecting the Expression of PELP1 Alternative Splices in Pigs.

Intramuscular fat (IMF) is a key meat quality trait. Research on the genetic mechanisms of IMF decomposition is valuable for both pork quality improvement and the treatment of obesity and type 2 diabetes. Copy number variations (CNVs) are a type of variant that may influence meat quality. In this study, a total of 1185 CNV regions (CNVRs) including 393 duplicated CNVRs, 432 deleted CNVRs, and 361 CNVRs with both duplicated and deleted status were identified in a pig F2 resource population using next-generation sequencing data. A genome-wide association study (GWAS) was then performed between CNVs and IMF, and a total of 19 CNVRs were found to be significantly associated with IMF. QTL colocation analysis indicated that 3 of the 19 CNVRs overlapped with known QTLs. RNA-seq and qPCR validation results indicated that CNV150, which is located on the 3'UTR end of the proline, as well as glutamate and the leucine rich protein 1 (PELP1) gene may affect the expression of PELP1 alternative splices. Sequence alignment and Alphafold2 structure prediction results indicated that the two alternative splices of PELP1 have a 23 AA sequence variation and a helix-fold structure variation. This region is located in the region of interaction between PELP1 and other proteins which have been reported to be significantly associated with fat deposition or insulin resistance. We infer that the CNVR may influence IMF content by regulating the alternative splicing of the PELP1 gene and ultimately affects the structure of the PELP1 protein. In conclusion, we found some CNVRs, especially CNV150, located in PELP1 that affect IMF. These findings suggest a novel mechanistic approach for meat quality improvement in animals and the potential treatment of insulin resistance in human beings.

Integrative Analysis of Nanopore and Illumina Sequencing Reveals Alternative Splicing Complexity in Pig Longissimus Dorsi Muscle.

Alternative splicing (AS) is a key step in the post-transcriptional regulation of gene expression that can affect intramuscular fat (IMF). In this study, longissimus dorsi muscles from 30 pigs in high- and low- IMF groups were used to perform Oxford Nanopore Technologies (ONT) full-length sequencing and Illumina strand-specific RNA-seq. A total of 43,688 full-length transcripts were identified, with 4,322 novel genes and 30,795 novel transcripts. Using AStalavista, a total of 14,728 AS events were detected in the longissimus dorsi muscle. About 17.79% of the genes produced splicing isoforms, in which exon skipping was the most frequent AS event. By analyzing the expression differences of mRNAs and splicing isoforms, we found that differentially expressed mRNAs with splicing isoforms could participate in skeletal muscle development and fatty acid metabolism, which might determine muscle-related traits. SERBP1, MYL1, TNNT3, and TNNT1 were identified with multiple splicing isoforms, with significant differences in expression. AS events occurring in IFI6 and GADD45G may cause significant differences in gene expression. Other AS events, such as ONT.15153.3, may regulate the function of ART1 by regulating the expression of different transcripts. Moreover, co-expression and protein-protein interaction (PPI) analysis indicated that several genes (MRPL27, AAR2, PYGM, PSMD4, SCNM1, and HNRNPDL) may be related to intramuscular fat. The splicing isoforms investigated in our research provide a reference for the study of alternative splicing regulation of intramuscular fat deposition.

Semiconductor-Metal Phase Transition and Emergent Charge Density Waves in 1T-ZrX2 (X = Se, Te) at the Two-Dimensional Limit.

A charge density wave (CDW) is a collective quantum phenomenon in metals and features a wavelike modulation of the conduction electron density. A microscopic understanding and experimental control of this many-body electronic state in atomically thin materials remain hot topics in materials physics. By means of material engineering, we realized a dimensionality and Zr intercalation induced semiconductor-metal phase transition in 1T-ZrX2 (X = Se, Te) ultrathin films, accompanied by a commensurate 2 × 2 CDW order. Furthermore, we observed a CDW energy gap of up to 22 meV around the Fermi level. Fourier-transformed scanning tunneling microscopy and angle-resolved photoemission spectroscopy reveal that 1T-ZrX2 films exhibit the simplest Fermi surface among the known CDW materials in TMDCs, consisting only of a Zr 4d derived elliptical electron conduction band at the corners of the Brillouin zone.

Epoxymicheliolide directly targets histone H2B to inhibit neuroinflammation via recruiting E3 ligase RNF20.

Monoubiquitination plays a critical role as one of the largest histone post-translational modifications (PTMs). Recent study has revealed that histone H2B monoubiquitination (H2Bub1) at a unique lysine 120 (K120) is widely involved in the development of inflammation progression. However, small-molecules directly targeting H2B to exert anti-inflammation effects via editing monoubiquitination have not been hitherto reported. In this study, we first discover a natural small-molecule epoxymicheliolide (ECL), which directly binds to H2B to inhibit microglia-mediated neuroinflammation in vitro and in vivo. Mechanism study suggests that ECL covalently modifies a previously undisclosed lysine 46 (K46) in H2B, and recruits E3 ubiquitin ligase RNF20 to promote H2Bub1 at K120. ChIP-seq and transcriptomics further reveal that ECL-mediated H2Bub1 markedly disrupts the AP-1 recruitment to proinflammatory gene promoters for microglia inactivation. Collectively, our findings suggests that K46 of H2B serves as a promising pharmacological target to develop small-molecule drugs against microglia-mediated neuroinflammation, and ECL represents a valuable lead compound for neuroinflammation via regulating histone monoubiquitination.

The Effects of Bioactive Compounds from Blueberry and Blackcurrant Powder on Oat Bran Pastes: Enhancing In Vitro Antioxidant Activity and Reducing Reactive Oxygen Species in Lipopolysaccharide-Stimulated Raw264.7 Macrophages.

In this study, blueberry and blackcurrant powder were chosen as the phenolic-rich enrichments for oat bran. A Rapid Visco Analyser was used to form blueberry and blackcurrant enriched oat pastes. An in vitro digestion process evaluated the changes of phenolic compounds and the in vitro antioxidant potential of extracts of pastes. The anthocyanidin profiles in the extracts were characterised by the pH differential method. The results showed that blueberry and blackcurrant powder significantly increased the content of phenolic compounds and the in vitro antioxidant capacity of pastes, while the total flavonoid content decreased after digestion compared to the undigested samples. Strong correlations between these bioactive compounds and antioxidant values were observed. Lipopolysaccharide-stimulated RAW264.7 macrophages were used to investigate the intracellular antioxidant activity of the extracts from the digested oat bran paste with 25% enrichment of blueberry or blackcurrant powder. The results indicated that the extracts of digested pastes prevented the macrophages from experiencing lipopolysaccharide (LPS)-stimulated intracellular reactive oxygen species accumulation, mainly by the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signalling pathway. These findings suggest that the bioactive ingredients from blueberry and blackcurrant powder enhanced the in vitro and intracellular antioxidant capacity of oat bran pastes, and these enriched pastes have the potential to be utilised in the development of the functional foods.

[Therapeutic effect and mechanism of Shouhui Tongbian Capsules on slow transit constipation model mice].

Shouhui Tongbian Capsules was used to explore the therapeutic effect and potential mechanism on slow transit constipation model mice induced by loperamide hydrochloride. In the experiment, loperamide hydrochloride-induced ICR mice were used as the model of slow transit constipation. Fifty ICR mice were divided into the blank group, model group and high, medium and low dose groups of Shouhui Tongbian Capsules extract(100, 200 and 400 mg·kg~(-1)). The model group and the administration groups were then modeled using loperamide hydrochloride intragastrically to obtain slow transit constipation. After successful modeling, high, medium and low doses of drugs were given to each drug group by intragastric administration. After 14 days of administration, the first defecation time, 6 h defecation grain number, 6 h defecation wet weight and dry weight, black feces discharged within 6 h and the fecal water content were measured. Intestinal tissues were taken for c-Kit and SCF immunohistochemical sections to detect the expression of c-Kit and SCF in the blank group, model group and high, medium and low dose groups of the medicinal extract of Shouhui Tongbian Capsules. The tissue changes in the intestinal wall of mice were detected by HE staining. At the same time, partial intestinal tissues were taken to test the activity of ATP synthase and isocitrate dehydrogenase in intestinal tissues of mice. RESULTS:: showed that Shouhui Tongbian Capsules effectively improved the symptoms of slow transit constipation in ICR mice and promoted intestinal movement. Shouhui Tongbian Capsules obviously shortened the time of discharging black stool for the first time, improved the intestinal propulsion rate, increased the water content and amount of feces, and improved the constipation symptoms. Mechanism study revealed that Shouhui Tongbian Capsules increased ATP synthase activity and mitochondrial isocitrate dehydrogenase activity in intestinal tissue, and up-regulated c-Kit/SCF signaling pathway to promote interstitial Cajal cells proliferation, intestinal nerve transmission, intestinal motility and transport capacity.

[Molecular mechanism study of Shouhui Tongbian Capsules on promoting energy metabolism of gastrointestinal stromal cells].

Mechanism study was performed to explore how Shouhui Tongbian Capsules promotes energy metabolism of gastrointestinal stromal cells. In this study, gastrointestinal stromal cells line GIST-882 was used as the model to explore energy metabolism regulation effects of Shouhui Tongbian Capsules extract(10, 20, 50 and 100 µg·mL~(-1)) by measuring the cell proliferation, ATP level, mitochondrial membrane potential, and mitochondrial isocitrate dehydrogenase activity. Meanwhile, Western blot was used to detect the proteins expression of SCF/c-Kit and CDK2/cyclin A signaling pathways. Our results showed that Shouhui Tongbian Capsules promoted cell proliferation and increased ATP level of gastrointestinal stromal cells. In addition, Shouhui Tongbian Capsules obviously improved mitochondrial structural integrity, and increased mitochondrial membrane potential in GIST-882 cells. Mechanism study revealed that Shouhui Tongbian Capsules increased mitochondrial isocitrate dehydrogenase activity and up-regulated the proteins expression of SCF/c-Kit and CDK2/cyclin A signaling pathways. Collectively, our study indicated that Shouhui Tongbian Capsules promoted the energy metabolism for gastrointestinal stromal cells proliferation by activating mitochondrial isocitrate dehydrogenase to induce ATP production, as well as activating SCF/c-Kit and CDK2/cyclin A signaling pathways.

[Evaluation of the Acute Toxicity and Genotoxicity of the Rice Biofortified with ß-Glucan].

OBJECTIVE: To provide a scientific evaluation of the food safety of the rice biofortified with ß-glucan. METHODS: The acute toxicity and genotoxicity of the rice were evaluated by 14-day feeding experiment, Ames experiment, erythrocyte micronucleus test and mouse lymphoma thymidine kinase gene ( TK) mutation assay respectively. RESULTS: In the acute toxicity test, there was no obvious toxicity of rice biofortified with ß-glucan, and no abnormality was found in anatomical observation. The median lethal dose (LD 50) to rats and mice wereall greater than 15 mg/kg, which belonged to the actual non-toxic level. Whether with S 9 activation or not, no genotoxicity was found to the tested strains TA97a, TA98, TA100, TA102 and TA1535. No induction of polychromatic erythrocytes and inhibition of bone marrow were found in erythrocyte micronucleus test. The results of TK gene mutation assay did not show the mutagenicity of ß-glucan bioaugmentation rice. All results of the three genotoxicity tests were negative. CONCLUSION: Under the current experimental conditions, ß-glucan biofortified rice showed no obvious acute toxicity and genotoxicity.

Direct Observation of Full-Gap Superconductivity and Pseudogap in Two-Dimensional Fullerides.

Alkali-fulleride superconductors with a maximum critical temperature T_{c}∼40 K exhibit a similar electronic phase diagram to that of unconventional high-T_{c} superconductors. Here we employ cryogenic scanning tunneling microscopy to show that trilayer K_{3}C_{60} displays fully gapped strong coupling s-wave superconductivity, accompanied by a pseudogap above T_{c}∼22 K and within vortices. A precise control of the electronic correlations and potassium doping enables us to reveal that superconductivity occurs near a superconductor-Mott-insulator transition and reaches maximum at half-filling. The s-wave symmetry retains over the entire phase diagram, which, in conjunction with an abrupt decline of the superconductivity below half-filling, indicates that alkali fullerides are predominantly phonon-mediated superconductors, although the electronic correlations also come into play.

Probiotics Can Boost the Antitumor Immunity of CD8+T Cells in BALB/c Mice and Patients with Colorectal Carcinoma.

BACKGROUND: The drug resistance and the immune suppression in the tumor microenvironment are important factors affecting tumor progression. Reversing drug resistance and changing tumor suppression microenvironment are ideal ways to inhibit tumor progression. OBJECTIVE: The aim of the study is to verify antitumor immune response of probiotics in patients with colorectal carcinoma and to explore its mechanism. METHODS: To detect the tumor samples of 122 patients with colorectal carcinoma after surgery, analyze the effect of probiotics on enhancing tumor-infiltrating CD8+T cells to inhibit colorectal carcinoma, and further verify the mechanism of probiotics on enhancing the antitumor immune response of CD8+T cells through animal experiments. RESULTS: The results of immunohistochemistry showed that the proportion of CD8+T cells in the patients treated with probiotics before surgery was increased significantly than that in other patients (P = 0.033). The results of flow cytometry also showed that the proportion of CD8+T cells in the probiotics group was higher than that in the nonprobiotics group (P = 0.029). Kaplan-Meier survival estimates also showed that the CD8+T cells, TNM stage, pathology grade, lymphatic metastasis, and probiotic treatment were significantly associated with the progression-free survival (PFS) (χ 2 = 9.684, P = 0.002 for CD8+T cells; χ 2 = 5.878, P = 0.015 for TNM stage; χ 2 = 7.398, P = 0.004 for pathology grade; χ 2 = 8.847, P = 0.003 for Lymphatic metastasis; and χ 2 = 4.622, P = 0.032 for the group (group A was treated with probiotics before surgery; group B was not treated with probiotics)). The experimental results in mice showed that probiotics could inhibit tumor growth and increase the proportion of CD8+T cells in mice; the difference was statistically significant (P = 0.037). It was also found that probiotic feeding could upregulate the expression of T-cell immunoglobulin mucin receptor 1(TIM-1) in CD8+T cells of mice and also found that probiotic feeding could downregulate the expression of programmed cell death protein 1 (PD-1) in CD8+T cells of mice, compared with the nonfeeding group; the difference was statistically significant (P = 0.045 for TIM-1 and P = 0.02 for PD-1, respectively). In order to further understand the functional status of CD8+T cells, we analyzed interferon-gamma (IFN-γ)+ T cells and tumor necrosis factor-α (TNF-α)+CD8+T cells by flow cytometry. The results showed that the proportion of IFN-γ + T cells and TNF-α +CD8+T cells significantly increased after probiotic treatment, compared with the nonprobiotic treatment group; the difference was statistically significant (P = 0.040 for IFN-γ + T cells and P = 0.014 for TNF-α +CD8+T, respectively). CONCLUSIONS: Probiotics can enhance the antitumor immune response of CD8+T cells. It can play a synergistic antitumor role. On the one hand, its mechanism is through regulating intestinal flora, and on the other hand, through regulating the antitumor immune function of CD8+T cells.

The Role of Shcbp1 in Signaling and Disease.

Src homolog and collagen homolog (Shc) proteins have been identified as adapter proteins associated with cell surface receptors and have been shown to play important roles in signaling and disease. Shcbp1 acts as a Shc SH2-domain binding protein 1 and is involved in the regulation of signaling pathways, such as FGF, NF-κB, MAPK/ERK, PI3K/AKT, TGF-ß1/Smad and ß -catenin signaling. Shcbp1 participates in T cell development, the regulation of downstream signal transduction pathways, and cytokinesis during mitosis and meiosis. In addition, Shcbp1 has been demonstrated to correlate with Burkitt-like lymphoma, breast cancer, lung cancer, gliomas, synovial sarcoma, human hepatocellular carcinoma and other diseases. Shcbp1 may play an important role in tumorigenesis and progression. Accordingly, recent studies are reviewed herein to discuss and interpret the role of Shcbp1 in normal cell proliferation and differentiation, tumorigenesis and progression, as well as its interactions with proteins.

Value of reduced glomerular filtration rate assessment with cardiometabolic index: insights from a population-based Chinese cohort.

BACKGROUND: Recent studies have suggested that cardiometabolic index (CMI), a novel estimate of visceral adipose tissue, could be of use in the evaluation of cardiovascular risk factors. However, the potential utility and clinical significance of CMI in the detection of reduced estimated glomerular filtration rate (eGFR) remains uncertain. The purpose of this study was to investigate the usefulness of CMI in assessing reduced eGFR in the general Chinese population. METHODS: This cross-sectional analysis included 11,578 participants (mean age: 53.8 years, 53.7% females) from Northeast China Rural Cardiovascular Health Study (NCRCHS) of general Chinese population (data collected from January 2013 to August 2013). CMI was calculated by triglyceride to high density lipoprotein cholesterol ratio multiply waist-to-height ratio. Reduced eGFR was defined as eGFR< 60 ml/min per 1.73m2. Multivariate regressions were performed to determine CMI's association with eGFR value and eGFR reduction, ROC analyses were employed to investigate CMI's discriminating ability for decreased eGFR. RESULTS: The prevalence of reduced eGFR was 1.7% in males and 2.5% in females. CMI was notably more adverse in reduced eGFR groups, regardless of genders. In fully adjusted multivariate linear models, each 1 SD increment of CMI caused 3.150 ml/min per 1.73m2 and 2.411 ml/min per 1.73m2 loss of eGFR before CMI reached 1.210 and 1.520 in males and females, respectively. In logistic regression analyses, per 1 SD increase of CMI brought 51.6% additional risk of reduced eGFR in males while caused 1.347 times of risk in females. After divided into quartiles, people in the top quartile of CMI had higher adjusted ORs of having reduced eGFR, with ORs of 4.227 (1.681, 10.627) and 3.442 (1.685-7.031) for males and females respectively. AUC of CMI was revealed to be 0.633 (0.620-0.646) in males and 0.684 (0.672-0.695) in females. CONCLUSIONS: Higher CMI was independently associated with greater burden of reduced eGFR, highlighting VAT distribution and dysfunction as a potential mechanism underlying the association of obesity with kidney damage and adverse cardiovascular outcomes. The findings from this study provided important insights regarding the potential usefulness and clinical relevance of CMI in the detection of reduced eGFR among general Chinese population.

Development of a recombinase polymerase amplification assay for Vibrio parahaemolyticus detection with an internal amplification control.

A novel RPA-IAC assay using recombinase polymerase and an internal amplification control (IAC) for Vibrio parahaemolyticus detection was developed. Specific primers were designed based on the coding sequence for the toxR gene in V. parahaemolyticus. The recombinase polymerase amplification (RPA) reaction was conducted at a constant low temperature of 37 °C for 20 min. Assay specificity was validated by using 63 Vibrio strains and 10 non-Vibrio bacterial species. In addition, a competitive IAC was employed to avoid false-negative results, which co-amplified simultaneously with the target sequence. The sensitivity of the assay was determined as 3 × 103 CFU/mL, which is decidedly more sensitive than the established PCR method. This method was then used to test seafood samples that were collected from local markets. Seven out of 53 different raw seafoods were detected as V. parahaemolyticus-positive, which were consistent with those obtained using traditional culturing method and biochemical assay. This novel RPA-IAC assay provides a rapid, specific, sensitive, and more convenient detection method for V. parahaemolyticus.

[Active compounds from Baoyuan decoction with myocardial protection activities and their potential targets].

Baoyuan decoction (BYD) is a classical Chinese formula for coronary heart disease with Qi deficiency, blood stasis tonifying Qi and Yang deficiency. However, the chemical material basis and underlying action mechanisms of BYD still lack systemic study. In order to clarify the active compounds and the potential action mechanisms of BYD, the oxygen-glucose deprivation/recovery (OGD/R)-induced H9c2 cells injury models was used to screen the monomeric compounds of BYD with myocardial protection activity. PubChem's BioAssay database was then used to analyze the potential targets of active monomeric compounds, classify the predicted biological targets, and analyze the internal relation between active compounds of BYD and biological targets. The screening results showed that BYD aqueous extract and 17 monomeric compounds could significantly increase the survival rate of OGD/R-induced H9c2 myocardial cells. The results of virtual targets screening study showed that 15 monomeric compounds and the potential mechanisms for myocardial protection were related to oxidative stress pathway, calcium ion pathway, mitochondrial protection, anti-apoptosis, etc. These results verified that BYD had myocardial protection effect, which was obtained by network regulation of multi-components and multi-targets. All these results provide the theoretical basis and references for the clinical usage of BYD in treatment of coronary heart disease.

Adverse effects of high glucose levels on somite and limb development in avian embryos.

Gestational diabetes has an adverse impact on fetal musculoskeletal development, but the mechanism involved is still not completely understood. In this study, we investigated the effects of high glucose on the developing somites and their derivate using the chick embryo as a model. We demonstrated that under high glucose, the number of generated somites was reduced and their morphology altered in 2-day old chick embryos. In addition, high glucose repressed the development of the limb buds in 5.5-day old chick embryos. We also demonstrated that high glucose abridged the development of the sclerotome and the cartilage in the developing limb bud. The sonic hedgehog (Shh) gene has been reported to play a crucial role in the development and differentiation of sclerotome. Hence, we examined how Shh expression in the sclerotome was affected under high glucose. We found that high glucose treatment significantly inhibited Shh expression. The high glucose also impaired myotome formation at trunk level - as revealed by immunofluorescent staining with MF20 antibodies. In the neural tube, we established that Wnt3a expression was also significantly repressed. In summary, our study demonstrates that high glucose concentrations impair somite and limb bud development in chick embryos, and suggests that Shh and Wnt genes may play a role in the underlying mechanism.

Photodynamic inactivation of methylene blue and tungsten-halogen lamp light against food pathogen Listeria monocytogenes.

The aim of this study was to verify the bactericidal effect and the damage of photodynamic inactivation (PDI) using methylene blue (MB) and tungsten-halogen lamp over Listeria monocytogenes via atomic force microscopy, absorption spectrophotometry, agarose gel electrophoresis, real-time PCR and SDS-PAGE. The obtained data indicated that the viability of L. monocytogenes was ca 7-log reduced by illumination with 10 min tungsten-halogen lamp light under the presence of 0.5 µg mL(-1) MB, and this bactericidal activity against L. monocytogenes of PDI increased proportionally to the concentration of MB and the duration of irradiation. Moreover, after irradiation with MB and visible light, the leakage of intracellular contents was estimated by spectrophotometer at OD(260) and OD(280), which correlated with morphological alterations. Furthermore, genomic DNA cleavage and protein degradation were also detected after PDI treatment. Consequently, breakage of the membrane, damage of the genomic DNA and degradation of bacterial proteins may play an important role in the mechanisms involved in PDI-MB bactericidal activity on L. monocytogenes.

Debittering effect of Actinomucor elegans peptidases on soybean protein hydrolysates.

Effects of the enzymes in Actinomucor elegans extract and the enzyme Alcalase 2.4L on debittering the soybean protein hydrolysates were investigated. When the protein was treated only with the latter, a strong bitterness formed; but it decreased if the protein was treated with both the enzymes. The more the enzymes were used, weaker was the bitterness tasted. SDS-PAGE profile and ESI-MS spectrum of the hydrolysates evidenced that the Alcalase could convert the protein into peptides rapidly, while the enzymes in the A. elegans extract were able to further degrade some peptides which were difficult or unable to be hydrolyzed by the Alcalase. Further systematic analysis of the peptidases showed that the Alcalase exhibited a significant endopeptidase activity towards NBZ-Phe-pNA substrate (p < 0.01), whereas many exopeptidases in the A. elegans extract had the carboxypeptidase activity towards N-CBZ-Ile-Leu (p < 0.01). It is concluded that those exopeptidases presented in the A. elegans extract can benefit by decreasing the bitterness of the soybean protein hydroysate. They are also capable of being used with the Alcalase in a single-step enzymatic reaction to prepare the bitterless protein hydrolysate, which may be an efficient application for food industry.