Abstract:In the new era of socialism with Chinese characteristics, the construction of the Chinese Communist Party in universities must start and end with the cultivation of talents, always adhere to the direction of socialist education, and resolutely implement the fundamental task of cultivating moral characters and educating people. The universities should lead the management of schools and grasp the core principles of cultivating talents by the construction of the Chinese Communist Part, promoting the in-depth integration of party construction and talents cultivation in colleges and universities, and actively exploring its function and practice path in party construction and talents cultivation. The system establishment of talents cultivation, staff and faculty, curriculum and course, and educational ecology should be supervised under construction of the Chinese Communist Party. The innovative education model named as 'The construction of the Chinese Communist Party and discipline' has been established to promote the development of disciplines and the continuous improvement of talents cultivation quality by the construction of the Chinese Communist Party.

Abstract:With the rapid development of economy in modern society, people's living standard has been significantly improved, and the dietary demand has shifted from survival to health. Future food has been a focus of attention in the academia and industryin food field. Carbohydrates, represented by starchy-based food, are the main energy sources of human body, however, starchy foods are easy to digest in human body, resulting in excess energy and a series of sub-health problems. Caloric reduction and prebiotic functions can be obtained by changing the molecular structures or bond types of starch and its partial degradation products.These new products are conducive to meet the nutrition and health needs of public consumers in the future, becoming an important part of future research in food field. This paper summarizes the types, biochemical characteristics and physiological functions of modified starch products, and the research progress of their preparation methodsis emphasized. This paper could provide theoretical basis and technical guidance for the further development and production of starch-based future food.

Abstract:Malonyl-CoA is an important precursor for the synthesis of plenty of valuable chemicals such as food and health products. The synthesis of malonyl-CoA has been a potential bottleneck in the production of target metabolites in E. coli. To solve this problem, this research aimed to promote accumulation of malonyl-CoA in E.coli through CRISPR interference(CRISPRi). Firstly, a malonyl-CoA biosensor was constructed to achieve fast and visible detection of the intracellular malonyl-CoA. Secondly, a CRISPRi/ddCpf1 system was constructed to repress gene transcription via ddCpf1(inactive Cpf1). And we attempted the fusion of Gp2 and ddCpf1(CRISPRi/ddCpf1-Gp2) and RNA polymerase. The results showed that Gp2 contributed a certain transcriptional inhibition effect, however, it seriously affected the growth. Finally, the CRISPRi/ddCpf1 system was applied to inhibit with a dual crRNA array, targeting acetaldehyde dehydrogenase & 3-oxoacyl-acyl carrier protein synthase II genes and 3-oxoacyl-acyl carrier protein synthase I & succinyl-CoA synthetase genes, greatly enhanced malonyl-CoA content in E. coli.

Abstract:The activity of inhibitory peptide (IPQVS) of dipeptidyl peptidase-4 (DPP-IV) was studied based on the Caco-2 cell model, and the effects of intestinal absorption and degradation on the inhibitory activity of DPP-IV were evaluated. The apparent absorption rate(Papp) values of IPQVS and their degraded peptide fragments were measured as (1.35±0.09)×10^-6 cm/s, (1.46±0.18)×10^-6 cm/s, (0.95±0.08)×10^-6 cm/s and (3.01±0.15)×10^-6 cm/s, respectively. IPQVS was mainly transported across Caco-2 cell monolayers through endocytosis. IPQVS inhibited the DPP-IV activity in the Caco-2 cell monolayer in a dose-dependent manner, and mRNA expression in DPP-IV was not affected (P>0.05). The IC₅₀ value was (101.66±6.02) μmol/L, which was higher than that measured in vitro by chemical substrate method. The results of molecular docking showed that the binding of DPP-IV with the degradation products of IPQVS, i.e., PQVS and QVS, was weaker than binding with IPQVS, and the binding sites were also significantly reduced, which greatly restricted the DPP-IV inhibitory activity of IPQVS.

Abstract:To realize the visual toxicity screening of T-2 toxin, the fluorescent plasmid pcDNA 3.1-TRE-mCherry was constructed using the key AP-1 target response element TREand red fluorescent protein (mCherry) in the toxicity pathway of T-2 toxin and the sensing screening model of fluorescent HEK293 cells was established. To verify the applicability of the cell sensing model, the toxicity detection of T-2 toxin residue in the actual samples and HT-2 toxin which was the main metabolite of T-2 toxin was conducted. The results showed that the intracellular red fluorescence intensity reached the maximum value and tended to be stable when the T-2 toxin stimulated the model cells for 8 h. When the concentration of T-2 toxin was in the range of 1~25 ng/mL, it was linearly correlated with fluorescence intensity, and the linear equation was y=1.149 38x+64.72, R2，R²= 0.969. According to the dose curve, the EC₅₀ of T-2 toxin was 16.27 ng/mL, and the detection limit was 0.691 ng/mL. The cell sensing model was used in the standard addition test. The average recovery of standard addition was 86.13%~126.20%, and the EC₅₀ of HT-2 toxin was 27.65 ng/mL after toxicity screening.

Abstract:The effects of high temperature treatment on changes of Anisakis larvae body and their residual proteins for allergic risk assessment of the contaminated Anisakis larvae in mackerel were investigated. Two high temperature processing methods, high temperature sterilization and deep frying, were used to treat Anisakis proteins within mackerel. The changes of Anisakis larvae genes were observed by conventional polymerase chain reaction(PCR) and quantitative real-time PCR (Q-PCR). The changes of Anisakis holoprotein were recorded by circular dichroism (CD) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The changes of immunogenicity of allergens were determined by Western blot analysis. The results showed that DNA and protein of Anisakis larvae were destroyed, and antigenicity decreased after heat treatment with 98.2% reduction of antigenicity of Anisakis proteins after 60 min of high temperature sterilization. Q-PCR could effectively detect Anisakis larvae residues in thermal processed foods. The effect of deep-frying on destroying the protein of Anisakis was more significant than that of high temperature sterilization. Q-PCR could quickly detect Anisakis larvae residues in mackerel. Both high-temperature sterilization and deep frying could effectively destroy Anisakis larvae residues, reducing the risk of allergenicity.

Abstract:The binding characteristics of three water-insoluble rice proteins(globulin, glutenin, prolamin) and Pb²⁺ were studied from the perspective of kinetics and thermodynamics to explore the binding behaviors of different rice protein components and heavy metal lead ion(Pb²⁺). The result showed that Pb²⁺ was rapidly bound to each insoluble rice protein, and the binding equilibrium was reached within 30 min. The prolamin showed the highest binding capacity with a binding adsorption quantity(q) of 20.54 mg/g. The binding of Pb²⁺ to rice proteins was consistent with the quasi-second-order kinetic model, and the Langmuir equation(R²=0.980~0.995) had greater fitting effect than that of the Freundlich equation(R²=0.847~0.987). The result indicated the interaction between protein subunits and Pb²⁺ was mainly by chemical absorptions. The thermodynamic parameters, i.e., ΔS°>0, ΔH°>0 and ΔG°<0, indicated the spontaneous, entropy-driven and endothermic binding reaction. X-ray photoelectron spectroscopy(XPS) showed that the characteristic peak intensity of N1s and S2p was significantly decreased after binding (P< 0.05), suggesting that the major binding sites of prolamin for Pb²⁺ were nitrogen- and sulfur-containing groups. Scanning electron microscopy (SEM) displayed that the prolamin structures aggregated and formed a compact cloddy structure after binding to Pb²⁺, which further verified the binding of Pb²⁺ to rice prolamin.

Abstract:In order to screena strain that could effectively degrade ciprofloxacinand to explore its degradation characteristics in the degradation process, high performance liquid chromatography was employed to screen ciprofloxacin degrading bacteria. This bacterium was then identified according to the colony morphology, physiological and biochemical characteristics as well as the 16S rDNA gene sequence analysis. The strain activity, and the degradation of intracellular and extracellular substances and cell walls on ciprofloxacin were also investigated with 4 μg/mL ciprofloxacin. The results showed that the degradation rate of ciprofloxacin by the screened Lactobacillus reuteri WQ-Y1 strain reached to 70.2% via physical adsorption and biodegradation. Furthermore, the degradation rates of ciprofloxacin by intracellular substances, extracellular substances and cell walls were 17.7%, 23.4% and 37.0%, respectively, which were far lower than that of the living bacteria. It could be concluded that the physical adsorption and the enzymolysis process of L. reuteri WQ-Y1 were not the only way of ciprofloxacin degradation, and it was also dependenton the complete liability of L. reuteri WQ-Y1.

Abstract:This study aimed to express gene eglA6 from Aspergillus niger, which encoding a highly thermal stable β-glucanase in Kluyveromyces lactis(K. Lactis), and investigated the properties of recombinant enzyme. The recombinant strain K. Lactis GG799/pKLAC1-eglA6 SL105 expressing β-glucanase was constructed by using the K. Lactis expression system with an enzyme activity of 23.0 U/mL in shake flask. The apparent molecular weight of recombinant enzyme AnEglA6k was 5.6×10⁴, which was significantly higher than those of the same gene in Pichia pastoris. The optimum pH of AnEglA6K was 5.0 and the optimum temperature was 75 ℃. The half-life of AnEglA6K was 65.0 min at 80 ℃. The specific activity of AnEglA6K was about 0.5 U/mL with Avicel as substrate. The expression products of eglA6 in K. lactis and Pichia pastoris were significantly different. The molecular weight of product expressed by eglA6 in K. lactis was significantly higher than that in Pichia pastoris, and the thermal stability and crystalline cellulose degradation activity of product expressed by eglA6 in K. lactis were also higher than those in Pichia pastoris. The recombinant glucanase derived from the expression of eglA6 gene by K. lactis has high thermostability and is suitable for application in feed industry.

Abstract:The difference in antibacterial activity of bitter peptides in yak milk hard cheese and the amino acid and position information of their interaction with different bacterial proteins were studied. The bioinformatic methods were used to calculate the molecular characteristics of four bitter peptides including RPKHPIK (RK7), TPVVVPPFL (TL9), VYPFPGPIPN (VN10) and SLVYPFPGPIPN (SN12) in yak milk hard cheese. The molecular docking tool was used to study the antibacterial activity of peptides and the molecular mechanism of the interaction between peptides and different bacterial proteins (E. coli 5BNS, Staphylococcus aureus 4ALM, Salmonella 6CH3) at the molecular level. BIOPEP database comparison was used to characterize the antibacterial activity of peptides. The results showed that the net charge of RK7 was 3.1, and the proportion of hydrophobic amino acids was 42.86%. The net charge of TL9 was 0, and the proportion of hydrophobic amino acids was 88.89%. The hydrophobic moments of VN10 and SN12 were 0.189 and 0.372, respectively, and the proportion of hydrophobic amino acids was 70.00% and 66.67%, respectively. Both RK7 and TL9 could form ligand-receptor complex conformations with 5BNS, 4ALM and 6CH3, while VN10 and SN12 could only form ligand-receptor complex conformations with 4ALM and 6CH3. After comparing RK7, TL9, VN10 and SN12 with the antibacterial peptide database, it was found that RK7 was a peptide with known antibacterial activity with the highest similarity of 100%, and TL9, VN10 and SN12 were potential new antibacterial peptides with antibacterial activity. The antibacterial activity of four bitter peptides was predicted through analysis of peptide molecular characteristics, molecular docking and database comparison. The inhibitory activity of E. coli was RK7 > TL9, while RK7 > VN10 > TL9 > SN12 for that of Staphylococcus aureus and RK7 > TL9 > VN10 > SN12 for that of Salmonella inhibitory activity. This study could provide a theoretical reference for studying the structural characteristics and antibacterial activity of bitter peptides from yak milk hard cheese at the molecular level.

Abstract:In order to improve the high-value utilization of different tissues and different mint varieties, spearmint, pepper, champagne and grapefruit were studied, and the volatile components in different tissue parts of 4 different mint varieties were qualitatively analyzed by gas chromatography-ion mobility spectroscopy (GC-IMS). The results showed that a total of 433 volatile substances were detected from the different parts of 4 different mint varieties. A total of 34 volatile substances were qualitatively identified, and the main components were alcohols, ketones, esters, aldehydes, olefins and heterocyclic compounds. Each variety of mint had its unique volatile components. Among them, the unique volatile components in spearmint were 1-pentanol and 4-hydroxy-2,5-dimethyl-3(2H) furanone, both of which had higher content in SPR (spearmint part 4). The unique volatile components in peppermint were isoamyl acetate and n-hexanol, both of which had higher content in PPLS-3 (peppermint part 3). The unique volatile component in grapefruit mint were 2,3-butanedione and hexanal, both of which had higher content in GPR (grapefruit part 4) and GPLS-3 (grapefruit part 3). Part PLS-1 was the main volatile components part of peppermint. Alcohol and ketone compounds were the key compounds of volatile components of peppermint which determined the flavor of different mint varieties.This study could provide a theoretical basis for the development and utilization of mint in medicine, flavors and fragrances, dyes, antioxidants, condiments, tea beverages and etc., and provide an effective method for the identification mint varieties.

Abstract:The preparation and identification of 1-pyrenebutyric acid artificial antigen was investigated in this paper.1-pyrenebutyric acid was coupled to bovine serum albumin (BSA) and chicken oval albumin (OVA) using the carbodiimide method (EDC) to synthesize the artificial immunogen PBA-BSA and artificial detection antigen PBA-OVA.The results of UV scanning and polypropylene gel electrophoresis (SDS-PAGE) showed that the antigen was successfully prepared. The potency of mouse-derived polyantisera was more than 1 000 with IC₅₀ of 14.31 ng/mL. The cross-reactivity with polycyclic aromatic hydrocarbons 1-pyrene methanol, 1-pyrene formaldehyde and pyrene was less than 14.40%, and the cross-reactivity with phenanthrene, naphthalene, benzopyrene, BSA and OVA was less than 0.05%. PBA-BSA antigen was successfully prepared, and a sensitive murine multi antiserum was obtained, laying the foundation for the subsequent preparation of monoclonal antibodies and the establishment of rapid immunological detection methods.