Improving Soluble Phenolic Profile and Antioxidant Activity of Grape Pomace Seeds through Fungal Solid-State Fermentation.

Grape pomace seeds contain abundant phenolic compounds, which are also present in both soluble and insoluble forms, similar to many other plant matrices. To further increase the extractable soluble phenolics and their antioxidant activities, grape pomace seeds were fermented with different fungi. Results showed that solid-state fermentation (SSF) with Aspergillus niger, Monascus anka, and Eurotium cristatum at 28 °C and 65% humidity had a significantly positive impact on the release of soluble phenolics in grape pomace seeds. Specifically, SSF with M. anka increased the soluble phenolic contents by 6.42 times (calculated as total phenolic content) and 6.68 times (calculated as total flavonoid content), leading to an overall improvement of antioxidant activities, including DPPH (increased by 2.14 times) and ABTS (increased by 3.64 times) radical scavenging activity. Furthermore, substantial changes were observed in the composition and content of individual phenolic compounds in the soluble fraction, with significantly heightened levels of specific phenolics such as chlorogenic acid, syringic acid, ferulic acid, epicatechin gallate, and resveratrol. Notably, during M. anka SSF, positive correlations were identified between the soluble phenolic content and hydrolase activities. In particular, there is a strong positive correlation between glycosidase and soluble phenols (r = 0.900). The findings present an effective strategy for improving the soluble phenolic profiles and bioactivities of grape pomace seeds through fungal SSF, thereby facilitating the valorization of winemaking by-products.

Production of Kinanthraquinone D with Antimalarial Activity by Heterologous Gene Expression and Biotransformation in Streptomyces lividans TK23.

Two new compounds, kinanthraquinone C (1) and kinanthraquinone D (2), were isolated along with two known compounds, kinanthraquinone (3) and kinanthraquinone B (4), produced by the heterologous expression of the kiq biosynthetic gene cluster and its pathway-specific regulator, kiqA, in Streptomyces lividans TK23. The chemical structures of compounds 1 and 2 were determined using mass spectrometry and nuclear magnetic resonance analyses. To examine a biosynthetic pathway of compounds 1 and 2, incubation experiments were conducted using S. lividans TK23 to supply the compounds 3 and 4. These experiments indicated that compounds 3 and 4 were converted to compounds 2 and 1, respectively, by the endogenous enzymes of S. lividans TK23. Compounds 2, 3, and 4 had antimalarial activities at half-maximal inhibitory concentration values of 0.91, 1.2, and 15 µM, respectively, without cytotoxicity up to 30 µM.

A mutant GH3 family ß-glucosidase from Oenococcus oeni exhibits superior adaptation to wine stresses and potential for improving wine aroma and phenolic profiles.

In this study, we conducted a comprehensive investigation into a GH3 family ß-glucosidase (BGL) from the wild-type strain of Oenococcus oeni and its mutated counterpart from the acid-tolerant mutant strain. Our analysis revealed the mutant BGL's remarkable capacity to adapt to wine-related stress conditions, including heightened tolerance to low pH, elevated ethanol concentrations, and metal ions. Additionally, the mutant BGL exhibited superior hydrolytic activity towards various substrates. Through de novo modeling, we identified specific amino acid mutations responsible for its resilience to low pH and high ethanol environments. In simulated wine conditions, the mutant BGL outperformed both wild-type and commercial BGLs, efficiently releasing terpene and phenolic aglycones from glycosides in wine grapes. These findings not only expand our understanding of O. oeni BGLs but also highlight their potential in enhancing wine production. The mutant BGL's enhanced adaptation to wine stress conditions opens promising avenue for improving wine quality and flavor.

Comparative functional analysis of malate metabolism genes in Oenococcus oeni and Lactiplantibacillus plantarum at low pH and their roles in acid stress response.

Oenococcus oeni and Lactiplantibacillus plantarum are major wine-associated lactic acid bacteria that positively influence wine by carrying out malolactic fermentation. O. oeni is the most widely used commercial starter in winemaking because of its fast and efficient malate metabolism capacity under harsh wine conditions. To date, very little is known about the specific molecular mechanism underlying the differences in malate metabolism between O. oeni and L. plantarum under harsh wine conditions. Therefore, in this study, the functions of genes encoding malic enzyme (ME) and malolactic enzyme (MLE) under acid stress in O. oeni and L. plantarum, previously described to have the ability to direct malate metabolism, were comparatively verified through genetic manipulation in L. plantarum. Results showed that the MLE was the only enzyme responsible for direct malate metabolism under acid stress in O. oeni and L. plantarum. In addition, the MLEs in O. oeni and L. plantarum were positively related to acid tolerance by metabolizing malate and increasing the medium pH. Furthermore, the MLE in O. oeni exhibited significantly higher malate metabolism activity than that in L. plantarum under acid stress.

Inhibitory Effects of Eurotium cristatum on Growth and Aflatoxin B1 Biosynthesis in Aspergillus flavus.

Probiotic strain Eurotium cristatum was isolated from Chinese Fuzhuan brick-tea and tested for its in vitro activity against aflatoxigenic Aspergillus flavus. Results indicated that E. cristatum can inhibit the radial growth of A. flavus. Furthermore, this inhibition might be caused by E. cristatum secondary metabolites. The ability of culture filtrate of strain E. cristatum against growth and aflatoxin B1 production by toxigenic A. flavus was evaluated in vitro. Meanwhile, the influence of filtrate on spore morphology of A. flavus was analyzed by scanning electron microscopy (SEM). Results demonstrated that both radial growth of A. flavus and aflatoxin B1 production were significantly weakened following increases in the E. cristatum culture filtrate concentration. In addition, SEM showed that the culture filtrate seriously damaged hyphae morphology. Gas chromatography mass spectrometry (GC/MS) analysis of the E. cristatum culture supernatant revealed the presence of multiple antifungal compounds. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis showed that the expression of aflatoxin biosynthesis-related genes (aflD, aflQ, and aflS) were down-regulated. Importantly, this latter occurrence resulted in a reduction of the AflS/AflR ratio. Interestingly, cell-free supernatants of E. cristatum facilitated the effective degradation of aflatoxin B1. In addition, two degradation products of aflatoxin B1 lacking the toxic and carcinogenic lactone ring were identified. A toxicity study on the HepG2 cells showed that the degradation compounds were less toxic when compared with AFB1.

Characterization of selenium-containing polysaccharides isolated from selenium-enriched tea and its bioactivities.

Two novel selenium polysaccharide fractions (SeTPS-1 and SeTPS-2) were isolated purified, characterized from Se-enriched tea. The results showed that the molecular weights and Se content of SeTPS-1 and SeTPS-2 were 1.7 × 104 Da, 1.3 × 104 Da, and 23.50 µg/g and 13.47 µg/g, respectively. SeTPS-1 and SeTPS-2 had absorption spectra typical of selenium esters. SeTPS-1 was composed of glucose and galactose at a molar ratio of 80.1:2.3, respectively, while SeTPS-2 was composed of arabinose, glucose, galactose and galacturonic acid with a molar ratio of 2.04: 48.83: 3.21: 1.30, respectively. Both SeTPS-1 and SeTPS-2 adopted a random coil conformation. Importantly, in vitro assessment of the antioxidant capacity revealed that SeTPS-1 is a more potent antioxidant compared to SeTPS-2. Both compounds were effective at reducing DNA damage induced by H2O2. The promising data suggesting that these compounds confer natural protection against DNA-damaging agents, thereby contributing to the functional food qualities of tea.

[Preventive and therapeutic effects of Qiwei Yugan Granule on hepatic fibrosis in rats].

Objective: To investigate the preventive and therapeutic effects of Qiwei Yugan Granule (QYG) on hepatic fibrosis in rats based on MMP-13/TIMP-1 imbalance. Methods: The rats were randomly divided into control group, model group, colchicine group (1.0×10-4 g/kg) and QYG treated groups (3.7, 7.4, 14.8 g/kg) (n=8). The rat model of hepatic fibrosis was established by injected with carbon tetrachloride subcutaneously for 4 weeks and treated with ethanol by gavage for 6 weeks. The effects of QYG on liver function, histopathology of liver, related indexes of serum liver fibrosis, and MMP-13, TIMP-1 in hepatic tissue were observed. Results: QYG at the doses of 14.8、7.4、3.7 g/kg could significantly decrease the serum levels of ALT, AST, HA, PCⅢ and C-Ⅳ, relieve the pathological changes of hepatic fibrosis, increase the activity of MMP-13, decrease the activity of TIMP-1 and alleviate the imbalance of MMP-13/TIMP-1. Among them, QYG had a certain trend of dose-effect relationship with TIMP-1 and MMP-13/TIMP-1 (P＜0.05, 0.01). Conclusion: QYG has the effect of preventing and treating liver fibrosis and one of mechanisms is to promote MMP-13/TIMP-1 to restore balance.

MicroRNA-379 inhibits laryngeal carcinoma cell proliferation and invasion through directly targeting TCF-4.

The expression pattern, functions, and detailed regulatory mechanisms of miR-379 in laryngeal carcinoma remain unknown. In the present study, we aimed to uncover novel potential miR-379 targets and shed light on its roles in laryngeal carcinoma. The expression level of miR-379 was measured based on the data obtained from the TCGA database and the cell lines. After miR-379 mimic transfection, cell proliferation, invasion and migration assay, and wound-healing assay in HEp-2 cell line were implemented to evaluate the effects of miR-379 on laryngeal carcinoma in vitro. The target genes for miR-379 in silico were predicted and validated using luciferase reporter assay. The miR-379 expression level was reduced in laryngeal carcinoma tissues and cell lines. Moreover, miR-379 overexpression inhibited the cell proliferation, migration, and invasion of laryngeal carcinoma cells. TCF-4 was detected as a direct target of miR-379 in laryngeal carcinoma. Furthermore, restored TCF-4 expression rescued the inhibitory roles of miR-379 overexpression on cell proliferation, migration, and invasion.Our study for the first time demonstrated that miR-379/TCF-4 might involve in the progression of laryngeal carcinoma, and miR-379 appears to serve as a novel tumor suppressor in laryngeal carcinoma.

One-step fabrication of robust fabrics with both-faced superhydrophobicity for the separation and capture of oil from water.

In this work, a facile and inexpensive one-step sonochemistry irradiation method was developed for the fabrication of SiO2 nanoparticles functionalized with octadecyltrimethoxysilane and their in situ incorporation into cotton fabrics. The double sides of as-prepared fabrics show both superhydrophobic and superoleophilic properties simultaneously with a high water contact angle of 159 ± 1° and an oil contact angle of 0°. Thus, it can be used to separate and capture a series of oils from water, like kerosene, toluene and chloroform, etc. In addition, the as-prepared fabrics still have superhydrophobicity with a water contact angle of above 150° after 40 separation cycles with the separation efficiency for the kerosene-water mixture always above 94.6%. More importantly, the as-prepared fabrics showed robust and stable superhydrophobic properties towards hot water, many corrosive solutions (acidic, basic, salt liquids) and mechanical abrasion. Therefore, this reported fabric has the advantages of scalable fabrication, high separation efficiency, stable recyclability, and excellent durability, exhibiting the strong potential for industrial production.

A sustainable slashing industry using biodegradable sizes from modified soy protein to replace petro-based poly(vinyl alcohol).

Biodegradable sizing agents from triethanolamine (TEA) modified soy protein could substitute poly(vinyl alcohol)(PVA) sizes for high-speed weaving of polyester and polyester/cotton yarns to substantially decrease environmental pollution and impel sustainability of textile industry. Nonbiodegradable PVA sizes are widely used and mainly contribute to high chemical oxygen demand (COD) in textile effluents. It has not been possible to effectively degrade, reuse or replace PVA sizes so far. Soy protein with good biodegradability showed potential as warp sizes in our previous studies. However, soy protein sizes lacked film flexibility and adhesion for required high-speed weaving. Additives with multiple hydroxyl groups, nonlinear molecule, and electric charge could physically modify secondary structure of soy protein and lead to about 23.6% and 43.3% improvement in size adhesion and ability of hair coverage comparing to unmodified soy protein. Industrial weaving results showed TEA-soy protein had relative weaving efficiency 3% and 10% higher than PVA and chemically modified starch sizes on polyester/cotton fabrics, and had relative weaving efficiency similar to PVA on polyester fabrics, although with 3- 6% lower add-on. In addition, TEA-soy sizes had a BOD5/COD ratio of 0.44, much higher than 0.03 for PVA, indicating that TEA-soy sizes were easily biodegradable in activated sludge.