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In this study, for the first time, we isolated a naringinase-producing strain from the Citrus aurantium L. var. amaraEngl flower soil and identified it as Serratia marcescensC10. In order to improve naringinase activity for its industrial application, single-factor experiments were carried out to obtain the factors that greatly affect naringinase activity, and based on three factors and three levels of Box-Behnken Designs (BBD), response surface methodology (RSM) was used to optimize the culture conditions consisting of naringin concentration, inoculation size and fermentation time. Results showed that naringin concentration and fermentation time had a highly significant influence and significant influence on naringinase activity, respectively. Additionally, inoculation size and fermentation time had an interaction with naringinase activity. The optimized conditions were a naringin concentration of 0.09 mg/mL, an inoculation size of 5.5%, and a fermentation time of 60 h. Under optimal culture conditions, the experiment naringinase activity was 30.81 U/mL, which was close to the predicted theoretical value of 31.23 U/mL. The optimized naringinase was used to remove naringin in grapefruit juice, and the removal rate was 88.85% under optimal reaction conditions.

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease characterized by lipid metabolic disorder primarily due to sedentary lifestyles and excessive food consumption. However, there are currently no approved and effective drugs available to treat NAFLD. In recent years, research has shown that dietary bioactive compounds, such as polysaccharides, polyphenols, flavones, and alkaloids, have the potential to improve NAFLD by regulating autophagy. However, there is no up-to-date review of research progress in this field. This review aims to systematically summarize and discuss the regulatory effects and molecular mechanisms of dietary bioactive compounds on NAFLD through the modulation of autophagy. The existing research has demonstrated that some dietary bioactive compounds can effectively improve various aspects of NAFLD progression, such as lipid metabolism, insulin resistance (IR), endoplasmic reticulum (ER) stress, oxidative stress, mitochondrial homeostasis, and inflammation. Molecular mechanism studies have revealed that they exert their beneficial effects on NAFLD through autophagy-mediated signaling pathways, predominantly involving transcription factor EB (TFEB), mammalian target of rapamycin (mTOR), adenosine monophosphate-activated protein kinase (AMPK), peroxisome proliferator-activated receptors (PPARs), SIRT, and PTEN-induced kinase 1 (PINK1)/parkin. Furthermore, the challenges and prospects of current research in this field are highlighted. Overall, this review provides valuable insights into the potential treatment of NAFLD using dietary bioactive compounds that can modulate autophagy.

A novel adsorbent was prepared from sugar beet pulp (SBP). SBP was saponified first, then loaded with FeCl3and hydrolyzed. The adsorption properties of Ca2+, Cu2+, and Pb2+by ferric hydroxide-loaded sugar beet pulp (SBPSFH) were studied. The effect of pH, adsorption time, initial concentration of ions, temperature and adsorbent dosage were studied on the adsorption process. In addition, the SBP and SBPSFH were characterized by SEM, XRD and FTIR. The results show that the SBPSFH has significantly improved the uptake of metal ions. At 40°C and pH 4.5–5.0, the adsorption of Ca2+, Cu2+and Pb2+by SBPSFH reached the equilibrium within 30 min. The optimal dosage was 10, 10, 5 g L–1, and the maximum adsorption capacity was 21.57, 38.25, 108.18 mg g–1, respectively. The adsorption data fitted well with the pseudo-second-order model and the adsorption isotherm conformed to the Langmuir equation, indicated that the adsorption process is dominated by monomolecular chemical adsorption. The thermodynamic parameters (ΔG°, ΔS° and ΔH°) showed that the adsorption is feasible, spontaneous and endothermic.

Tembusu virus (TMUV), a pathogenic member of the Flavivirus family, is an infectious diseases that seriously jeopardize duck health in 2010 in China. TMUV disease causes significant economic losses to the duck industry. This study aimed to prepare monoclonal antibodies against TMUV prM protein and to identify their epitopes. The 501bp prM gene was amplified to the pET-32a prokaryotic expression vector and expressed as a recombinant protein of size 38 KD in Escherichia coli.The purified recombinant proteins were inoculated into BALB/c mice to generate splenic lymphocytes capable of secreting anti-prM antibodies, and hybridoma cells were obtained after fusion with SP2/0 cells. A new hybridoma cell line named B27, which stably secreted IgG1-antibody against TMUV prM with high antibody titers up to 1:1:3,276,800 was screened. This monoclonal antibody (mAb) is well specific and can be used for ELISA/Western-blot (WB)/indirect fluorescence assay (IFA) etc. The mAb B27 has poor neutralization ability and concentration dependence, with a maximum neutralization degree of 23.87% at antibody dilution 10−6. Next, we truncated prM gene and expressed the truncated protein to screen antigen epitopes. The mAb's linear antigen epitope of the TMUV prM protein was first identified and was accurate to 6 consecutive amino acids 59GYEPED64,which located in the pr protein. Bioinformatic analysis showed that this antigenic epitope was located on the surface of the antigen, which was conducive to the direct contact of antigen antibody and conformed to the properties of antigenic epitopes. In addition, its 6 amino acids are highly homologous among 27 published TMUV strains, indicating that its epitope is stable. This study will help to further understand the protein structure and the function of prM, and lay the foundation for establishing specific prM detection methods and the mechanistic study of TMUV prM protein.

A novel adsorbent (FCDSBP) from de-pectinated sugar beet pulp (DSBP) was successfully prepared by loading the surface of citric acid modified DSBP (CDSBP) with amorphous Fe-oxide species and FCDSBP was used to investigated the removal of metal ions (Cu2+and Pb2+) from aqueous solutions. The obtained composites were characterized by FTIR, XRD and SEM. According to all characterization results, amorphous iron oxides of FeOxtype and hydroxylated oxide were located on the FCDSBP surface. Due to the presence of amorphous Fe-oxide species and hydroxylated oxide, the adsorption capacity of FCDSBP for Cu2+and Pb2+was approximately three times that of CDSBP. In addition, the obtained experimental data of adsorption of metal ions by the FCDSBP and CDSBP fitted the Langmuir isotherm model well, and the pseudo-second-order kinetic model could be used to describe adsorption process. According to the calculated thermodynamic parameters, the metal ions adsorption process was endothermic and spontaneous in nature.

The authors investigate a kind of degenerate quadratic Hamiltonian systems with saddle-loop. Under quadratic perturbations, it is proved that the perturbed system has at most two limit cycles in the finite plane. The proof relies on a careful analysis of a related Abelian integral.