Loading...

Table of Content

      
    20 November 2024
    Volume 59 Issue 11
    Microbial diversity and succession of large koji cakes used in soy-flavor Baijiu
    ZHANG Lijie, WU Tingting, FAN Shaohui, HE Guoliang, ZHENG Yangyun, CAI Xiaomin, ZHU Weijiang, XU Yan
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  1-7.  doi:10.6040/j.issn.1671-9352.0.2024.364
    Abstract ( 32 )   PDF (7843KB) ( 25 )   Save
    References | Related Articles | Metrics
    Soy-flavor Baijiu is a distinctive traditional beverage in China. The flavor quality is influenced by the primary saccharification fermentation agent of the large koji cake. We employed high-throughput sequencing and additional technologies to systematically examine changes in physical and chemical parameters, as well as the dynamics of microbial communities in large koji cakes at various fermentation stages, and analyzed the driving factors of microbial succession throughout the fermentation process of large koji cakes. The findings indicated that with advancing fermentation, the moisture content of the large koji cakes diminishes, starch undergoes rapid degradation, and the glucose concentration remains relatively stable. The diversity of microorganisms progressively diminished, with Bacillus and Saccharomycopsis emerging as the predominant species. The most abundant microbial species in large koji cakes were Bacillus subtilis (relative abundance of 2.16%-75.07%)and Saccharomycopsis fibuligera (relative abundance of 6.16%-98.32%). Subsequent investigation revealed that environmental parameters, including fermentation temperature, acidity, and glucose content, significantly influence microbial community structure and function. These findings reveal the main microbial structure and succession rules in large koji cakes of Soy-flavor Baijiu, offering a novel scientific foundation for a comprehensive knowledge of its brewing mechanism.
    Effects of semisolid-state fermentation of probiotics consortium on release of effective constituents from licorice and their activities
    ZHOU Kemeng, DAI Jianying, DONG Yuesheng, DANG Yanyan, ZHANG Genlin, XIU Zhilong
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  8-19.  doi:10.6040/j.issn.1671-9352.0.2023.437
    Abstract ( 21 )   PDF (4071KB) ( 11 )   Save
    References | Related Articles | Metrics
    The cell wall of licorice prevents the release of effective substances such as flavonoids and polysaccharides from liquorice cells. In this study, a mixed probiotics consortium composed of Saccharomyces cerevisiae, lactic acid bacteria and Bacillus was used in semisolid-sate fermentation of liquorice powder to promote the release of effective substances. The inhibition ability on pathogenic bacteria and tyrosinase as well as antioxidant activities of the fermentation broth were evaluated. The experimental results showed that the extraction rates of polysaccharides, flavonoids, glycyrrhizic acid and glycyrrhetinic acid could be considerably compared with the Soxhlet method. The inhibition rate of the mixed fermentation supernatant on Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii was 73.85%, 45.57% and 39.92%, respectively. The scavenging rates of the mixed fermentation supernatant to 1,1-diphenyl-2-picrylhydrazyl(DPPH), 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate(ABTS), 2-Phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl(PTIO), superoxide radical and hydroxyl radical were superior to other extraction methods. The inhibition rate on tyrosinase was 61.62%. The semisolid-state fermentation of licorice by probiotic consortium provides high-quality raw materials for the development of health-care products and cosmetics.
    Key preparation processes and applications of arabinoxylan
    CHEN Guang, LYU Jiangtao, QIU Xueliang, DING Libing, CAI Yichen, CHEN Yue, LIU Zhenxue, WANG Lushan
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  20-30.  doi:10.6040/j.issn.1671-9352.0.2023.481
    Abstract ( 31 )   PDF (6626KB) ( 14 )   Save
    References | Related Articles | Metrics
    Arabinoxylan(AX)was an important component of hemicellulose in plant cell walls, which wa s found in grains such as corn, wheat, barley and rice. AX not only had antioxidant, prebiotic potential, and immunomodulatory activity but also had water retention, biocompatibility, and mechanical properties. At the same time, it could be converted into clean energy. Therefore, it was widely used in food, medical, industrial, and other fields. The biological activity of AX was closely related to its chemical structure. The fine structures and the functional properties of AX depended on different cereal sources and different extraction methods. In this paper, we summarized several aspects of AX, which contained the structural characteristics, biological activities, serval methods of extraction and purification from various raw materials, and the application.
    Comparison studies of epiphytic microbial communities associated with different growth regions of Sargassum muticum
    GUO Zhansheng, CHANG Lirong, CHEN Wenjing, HOU Xuguang, SHI Kuntao
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  31-39.  doi:10.6040/j.issn.1671-9352.0.2023.375
    Abstract ( 15 )   PDF (7112KB) ( 7 )   Save
    References | Related Articles | Metrics
    Sargasum muticum is one of the important species for constructing seaweed beds distributed in the intertidal zone of the Yellow Sea and Bohai Sea of China, with high ecological and economic values. While the basic ecological studies of S. muticum are mainly from a macrocosmic viewpoint, our understanding of their impact on microecology remains limited. In this study, the epiphytic microbial communities associated with different growth regions(including vesicles, blades, stalks and holdfast)of S. muticum collected from the intertidal zone of Jingzi Bay were characterized using high throughput sequencing technology, the natural seawater was served as control. The results showed that the holdfast sample of S. muticum displayed the highest level of microbial richness and diversity, while the lowest microbial richness was in the blade sample, and the microbial diversity and evenness were lower in the vesicle sample than in other growth regions. PCoA and Anosim analyses showed that the structure of the microbial communities on S. muticum is distinct from those of planktonic communities(p<0.05), while no significant differences were observed between different growth regions of S. muticum(p≥0.05). The community structure analysis results showed that Proteobacteria, Firmicute and Bacteroidota were the common predominant phyla, with the relative abundance of 80.51%-87.64%; Yoonia- Loktanella was most dominant genus in the samples from the vesicle, blade and stalk(11.90%-18.02%), the dominant genus of the holdfast samples is Pleurocapsa_ PCC-7319(7.48%). A total of 15 biomarkers were identified using LEfse analysis, of which 5, 1, and 9 biomarkers in the sample groups from vesicle, holdfast and water, respectively. The metagenome function prediction of S. muticum was carried out using Tax4Fun software, metabolism was prominent common function(46.16%-48.35%), followed by genetic information processing(21.18%-22.88%)and environmental information processing(12.03%-13.96%). This study would provide a theoretical basis for in-depth understanding of the ecological characteristics of S. muticum by comparing the epiphytic microbial communities associated with different growth regions of the seaweed.
    Staining methods on arbuscular mycorrhizal fungi in Lycium barbarum roots and the relationship between colonization rate and soil factors
    YANG Mu, JI Shenglian, GUO Huan, DUAN Guozhen, FAN Guanghui, LI Jianling, WANG Zhanlin
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  40-50.  doi:10.6040/j.issn.1671-9352.0.2023.488
    Abstract ( 18 )   PDF (6530KB) ( 4 )   Save
    References | Related Articles | Metrics
    Understanding the infection and colonization of arbuscular mycorrhizal fungi(AMF)is the basis for mobilizing indigenous AMF to improve plant resistance. Lycium barbarum in nine fields of the Qaidam Basin were the subject. Based on the basic staining method of AMF, previous studies were optimised to investigate the main factors influencing the observation of AMF on the roots of perennial field-grown L.barbarum. The influence of different regions, soil pH, soil physicochemical properties and the colonization rate of AMF on L.barbarum were also compared. The results showed that the optimal observation effect of AMF colonization rate on the roots of Perennial field-grown L.barbarum in the Qaidam Basin was achieved by the following steps. First, the fixed root segments were placed in a 10% KOH 90 ℃ for 90 min, then in the boiling alkaline peroxide(3 mL NaOH+30 mL 10% H2O2+H2O to 600 mL)for 15-20 min, followed by 5 min of H2O2 bleaching, 5 min of lactic acidification, 5 min of acetone ink staining and 30 min of lactic acid glycerol 90 ℃ decolourisation. This method can clearly observe the structures of vesicles and hyphae in the roots of perennial field-grown L.barbarum. The average AMF colonization rate of perennial field-grown L.barbarum in the Qaidam Basin was about 41.32%. RDA analysis showed that the AMF colonization rate in L.barbarum roots was mainly affected by factors such as soil pH, available phosphorous content(xAP), and available potassium content(xAK), among which the soil pH showed a significant positive correlation with the AMF colonization rate, while xAP and xAK showed a significant negative correlation with the colonization rate.
    Effect of oxidative stress on a cysteine-conjugated antibody-drug conjugate
    QU Yaocheng, YAO Xuejing, SUN Yundong
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  51-63.  doi:10.6040/j.issn.1671-9352.0.2023.504
    Abstract ( 22 )   PDF (10130KB) ( 10 )   Save
    References | Related Articles | Metrics
    We investigated the effects of oxidative stress on the structure and function of a cysteine(Cys)-conjugated antibody-drug conjugate(ADC). The research object was a Cys-conjugated, c-Met ADC(referred to as c-Met ADC). Firstly, the samples were incubated in different proportions of H2O2 solution for forced oxidation. Then, multiple analytical techniques were used to deeply characterize the structural and functional changes of the oxidized samples. H2O2 induced oxidative stress resulted in Met oxidation on the c-Met ADC antibody backbone and thioether bond cleavage in the linker. Met oxidation further led to a decrease in the thermal stability and neonatal Fc receptor(FcRn)affinity of the c-Met ADC, which were mainly related to Met257 oxidation on the antibody Fc. The cleavage of thioether bonds led to a decrease in the biological activity of the c-Met ADC. Oxidative stress was a key influencing factor on the stability of c-Met ADC, and the Met257 oxidation and thioether bond cleavage caused by it should be strictly monitored as its critical quality attributes in daily release and stability studies. At the same time, it should also be avoided to be exposed to oxidative environments or to mitigate the impact of oxidative stress on its structure and function by optimizing environmental factors.
    Mechanism of Acotus tatarinowii Schott in treating Alzheimers disease
    CHEN Liang, FANG Chengwei, MENG Ji, MA Xiuping, ZHU Dan, LI Jiaxin
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  64-73.  doi:10.6040/j.issn.1671-9352.0.2023.485
    Abstract ( 24 )   PDF (11956KB) ( 9 )   Save
    References | Related Articles | Metrics
    We analyzed the mechanism of action of Acorus tatarinowii Schott(ATS)in the treatment of Alzheimers disease(AD)based on network pharmacology, molecular docking, and experimental verification. After the active components of ATS were collected by TCMSP database and literature review, the targets of active components of ATS were predicted by Swiss target prediction database. Protein-protein interaction analysis was carried out using STRING database. GO and KEGG signal pathway enrichment analysis was carried out by DAVID database for key targets; Finally, AutoDock was used to verify the molecular docking between active ingredients and important targets, and the effect of ATS on AChE activity was verified by enzyme inhibition experiments. 7 active ingredients were screened, corresponding to 254 targets, 1 981 AD targets, 120 drug disease common targets. GO enrichment analysis obtain 306 entries, KEGG pathway enrichment analysis obtained 79 signal pathways, it mainly included cancer, Estrogen and VEGF signaling pathway; Molecular docking results showed that AChE and AKT1 target could spontaneously bind to most active components of ATS stably. Enzyme inhibition experiment showed that ATS can inhibit AChE activity. In this study, the mechanism of action of ATS in the treatment of AD was predicted and verified from the aspects of network pharmacology, molecular docking and enzyme inhibition experiments, so as to provide reference and basis for clinical application and further development of ATS.
    Effect of PCM-PCHE on SCO2 Brayton cycle under variable operating conditions
    ZHANG Lianjie, LI Wei, YANG Ping, ZENG Min, WANG Qiuwang
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  74-84.  doi:10.6040/j.issn.1671-9352.0.2024.263
    Abstract ( 19 )   PDF (10722KB) ( 9 )   Save
    References | Related Articles | Metrics
    In order to weaken the influence of variable operating conditions such as temperature instability on the supercritical carbon dioxide(SCO2)Brayton cycle, this study fitted and generalized the results of the phase change materials-printed circuit heat exchanger(PCM-PCHE)embedded in numerical simulations, and established a dynamic simulation model of the coupling between PCM-PCHE and SCO2 Brayton cycle. The coupled dynamic simulation model of SCO2 Brayton cycle was established, and the model validation was completed by the comparison of its parameters with experimental values under stable conditions. Then the variable operating conditions characteristics of the core parameters of the SCO2 Brayton cycle system were observed under temperature fluctuations as well as load variations. The results showed that the addition of PCM-PCHE has a better stabilizing effect on the SCO2 Brayton cycle system with variable operating conditions, which reduced the fluctuation amplitude of the cycle efficiency by 40.8%, and the stabilized value of the rotor speed was lower than that without PCM by 18 r/min, and at the same time, it weakened the variation amplitude of the isentropic efficiency of the turbomachinery when the load varied, which was conducive to the stabilization of the system.
    Enzymatic catalysis for methyl esterification of high acid value rice bran oil deodorized distillate
    ZHOU You, LI Pandeng, HE Leiyu, SUN Lihui
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  85-92.  doi:10.6040/j.issn.1671-9352.0.2024.316
    Abstract ( 21 )   PDF (4715KB) ( 3 )   Save
    References | Related Articles | Metrics
    In order to improve the utilization rate of rice bran oil deodorized distillate, methyl esterification of rice bran oil deodorized distillate was catalyzed by the liquid lipase Eversa Transform 2.0. The esterification rate and the content of free fatty acids in the system were used as the evaluation indicators. The effects of reaction time, enzyme amount, molar ratio of alcohol to oil, and water content on the esterification rate were studied by single factor experiments. On this basis, the response surface experiment was used to optimize the esterification conditions. The results showed that the optimal conditions for methyl esterification of rice bran oil deodorized distillate were 1.2% enzyme addition, 5.9∶1 molar ratio of alcohol to oil, 11.8% water content, and 9.6 h reaction time. Under these conditions, the esterification rate was 97.37%. In summary, the low-cost liquid lipase Eversa Transform 2.0 catalyzed the esterification of rice bran oil deodorized distillate, which could obtain a high esterification rate and provide a green and efficient pretreatment method for the separation and extraction of phytosterols, vitamin E, and other active components in the system.
    Preparation of copper mesh loading Ag/SDS nested-network with fluorescence enhancement performance
    TIAN Shuo, YUAN Zhipeng, ZHANG Yanfang
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  93-99.  doi:10.6040/j.issn.1671-9352.0.2023.459
    Abstract ( 22 )   PDF (7628KB) ( 6 )   Save
    References | Related Articles | Metrics
    Appropriate distance between metal ions and fluorophore is the key to obtain high fluorescence intensity, while the tuning of the appropriate distance between them is fussy. In this paper, the carbon film of copper mesh was firstly used as the isolation layer between Ag and fluorophore, displacement reaction between AgNO3 and copper mesh was used to prepare copper mesh loading Ag/SDS nested-network, which exhibits efficient fluorescence enhancement effect.
    A petroleum multi-refinery production optimization method based on successive linear programming
    DONG Fenglian, ZHANG Fengsheng, WEI Zhiwei, SUN Xin, LI Yuewen
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  100-109.  doi:10.6040/j.issn.1671-9352.0.2023.457
    Abstract ( 25 )   PDF (716KB) ( 15 )   Save
    References | Related Articles | Metrics
    To enhance the profitability of integrated oil companies and address the optimization problem of multi-refinery production planning with integer variables and non-convex bilinear constraints, we established an optimization model for multi-refinery production planning using operations research methods by holistically optimizing the allocation of crude oil among multiple refineries, the load of each refinerys units, and the product slate. We proposed a solution method for mixed integer nonlinear programming(MINLP)based on successive linear programming(SLP)and introduced a branching strategy tailored to business characteristics, enabling the solution process to converge rapidly and provide high-quality solutions. Validation analysis using actual data from a petroleum enterprise demonstrated that the proposed algorithm offered advantages in both the models objective value and solution efficiency.
    A coupling study of habitat quality and urbanization in the lower Yellow River
    SUN Jinxin, HAN Mei, KONG Fanbiao, WEI Fan
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  110-125.  doi:10.6040/j.issn.1671-9352.0.2022.553
    Abstract ( 24 )   PDF (12569KB) ( 6 )   Save
    References | Related Articles | Metrics
    In the process of urbanization, natural habitats have been degraded to different degrees by human disturbance, which hinders high-quality regional development. The coupled and coordinated relationship between habitat quality and urbanization development needed to be reconciled. In this paper, we used the InVEST model to analyze the spatial and temporal evolution characteristics of habitat quality in the lower Yellow River from 2000 to 2020, and used the light index to characterize the urbanization level, and evaluated the interactive coupling relationship between habitat quality and urbanization with the help of coupled coordination model and decoupling model. The results showed that(1)From 2000 to 2020, the overall level of habitat quality in the lower Yellow River was poor but gradually tended to improve. The areas with higher habitat quality were mainly concentrated in coastal and lakeside wetlands, southwestern and eastern hills and mountains, showing a general trend of low in the middle and high at the edges, with a more stable distribution pattern.(2)The overall level of urbanization in the lower Yellow River has improved and regional differences have been enhanced, gradually developing into a pattern of urbanization level distribution with Ji-Zi and Zheng-Xin urban areas as important growth poles.(3)The coupling and coordination stage of habitat quality and urbanization in the lower Yellow River belonged to the basic coordination stage. The number of counties transformed to the direction of decoupling decreased. The decoupling types are mainly strong negative decoupling and weak decoupling two negative decoupling types, and the proportion of negative decoupling types gradually decreased. The coupling coordination degree of the two systems deepened, the decoupling degree decreased, and the overall development in the direction of coordination.
    Supply chain financing strategy with limited green marketing funds
    SU Ningning, HE Xinhua, HU Wenfa
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  126-138.  doi:10.6040/j.issn.1671-9352.0.2022.617
    Abstract ( 25 )   PDF (8686KB) ( 6 )   Save
    References | Related Articles | Metrics
    A decision model of retailer green marketing capital constraints was constructed, two schemes of bank credit financing(BCF)and trade credit financing(TCF)were compared and analyzed to make the optimal decisions of the green supply chain under the traditional channel and the dual channel respectively. Finally, the validity of the conclusion was verified by numerical simulation. The results show that:(1)In the traditional channel, retailers prefer TCF, and as the green marketing factor increases, the overall profit of the supply chain rises.(2)In the dual channel, when the green marketing factor was low, the retailers financing choice depends on the interest rate level, but the supply chain as a whole prefers BCF; as the green marketing factor and channel preference factor increase, and it is easier to achieve a win-win situation by adopting TCF.(3)Combining the optimal decisions of members under different channel structures: members revenue and product greenness levels are better under the dual-channel structure than in the traditional channel structure, and manufacturers can take the initiative to lower interest rates to facilitate retailers financing, to increase retailers incentive to order and thus improve economic efficiency.
    Retailer dual-purpose selling and supplier encroachment strategy
    FU Yumin, WU Jianyun
    JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2024, 59(11):  139-148.  doi:10.6040/j.issn.1671-9352.0.2022.483
    Abstract ( 19 )   PDF (676KB) ( 9 )   Save
    References | Related Articles | Metrics
    In the case of the retailer adopting dual-purpose selling, we explores the interaction between the suppliers encroachment through the e-commerce platform and the retailers dual-purpose selling. The results show that the decision of supplier benefits from the retailers dual-purpose, and the suppliers encroachment strategy depending on the e-commerce platforms commission rate and the corporate social responsibility level of the retailer. When the commission rate or the level of corporate social responsibility is low, the supplier encroaches on the market through the e-commerce platform, and the retailer can restrain the suppliers encroachment by enhancing its dual-purpose level. Otherwise, the supplier doesnt encroach on the market. When the supplier encroaches on the market, the e-commerce platform charging an appropriate commission rate enables the supplier and the retailer to achieve a win-win outcome, and the retailer with the higher dual-purpose level can benefit more from the suppliers encroachment. In addition, the suppliers encroachment can further enhance consumer surplus on the basis of the retailers dual-purpose selling.