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18 June 2023, Volume 40 Issue 3 Previous Issue    Next Issue

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Analysis of the development trend of synthetic biology industry under the background of “14th Five-Year Plan” WANG Haoqi, GAO Hao, XIN Fengxue 2023, 40 (3):  1.  doi: 10.3969/j.issn.2095-1736.2023.03.001 Abstract ( 571 )   PDF   Save Synthetic biology is revolutionizing the biotechnology industry, which is increasingly applied in natural products, medicine, energy, industry, et al. With the promulgation of the “14th Five-Year Plan” for the development of biological economy, the heat of synthetic biology, known as the “third biotechnology revolution”, is rising. Synthetic biology is poised to disrupt many traditional industries with more economical and environmentally friendly features. The industry policies of synthetic biology and the domestic synthetic biology industries in China were reviewed. The synthetic biology focused on the fields of biochemicals, biopharmaceuticals, agriculture, food, medical beauty and cosmetics, and its future development was also prospected. Related Articles | Metrics

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Bax and Bak regulate ferroptosis via Nrf2/GPX4 signaling pathway HAN Jing, ZHAO Guoping 2023, 40 (3):  6.  doi: 10.3969/j.issn.2095-1736.2023.03.006 Abstract ( 557 )   PDF   Save Immortalized mouse embryonic fibroblasts (MEFs) with wild-type (WT), Bak/Bax double knockout (Bak/Bax-DKO), Bak knockout (Bak-KO) and Bax knockout (Bax-KO) were used to investigate the role and possible mechanisms of pro-apoptotic protein Bak/Bax on the erastin-induced ferroptosis. The survival rates and reactive oxygen species (ROS) production were determined by CCK-8 and flow cytometry, the levels of GSH/GSSG were measured by testing kits. In addition, the expression levels of target genes and proteins were detected by real-time fluorescence quantitative PCR (RT-qPCR) and Western Blot. The results showed that knockout Bak and Bax inhibited erastin-induced ferroptosis significantly, and the expression levels of nuclear factor-erythroid 2-related factor 2 (Nrf2) protein, glutathione peroxidase 4 (GPX4) protein and mRNA were increased significantly in Bak/Bax-DKO cells. Further studies showed that the absence of Bax also inhibited erastin-induced ferroptosis and promoted the expression levels of GPX4. However, no significant changes on erastin-induced ferroptosis and GPX4 expression were found in Bak-KO cells. These results indicated that Bak and Bax promoted erastin-induced ferroptosis via Nrf2/GPX4 signaling pathway and Bax rather than Bak played a key role. Related Articles | Metrics

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Regulation of the crp gene on antibiotic biosynthesis in Pseudomonas protegens H78 NIE Chenxi, XIANG Tao, ZHANG Xuehong, HUANG Xianqing 2023, 40 (3):  11.  doi: 10.3969/j.issn.2095-1736.2023.03.011 Abstract ( 171 )   PDF   Save The crp gene (encoding the cAMP receptor protein), as a global regulatory gene, widely exists in various bacteria and exhibits different regulatory functions in different strains. P. protegens H78 is capable of producing multiple broad-spectrum antibiotics such as pyrrolnitrin (Prn), 2,4-diacetylphloroglucinol (2,4-DAPG), and pyoluteorin (Plt). In order to investigate the global regulatory effect of the crp gene on the synthesis of antibiotics including Prn, 2,4-DAPG and Pltin P. protegens H78, the influences of crp gene on the synthesis and gene expression of these three antibiotics were analyzed by gene knockout, HPLC analysis, and lacZ reporter gene analysis. The results suggested that the knockout of crp gene in H78 strain significantly inhibited Prn synthesis operon (prnABCD) expression, significantly upregulated Plt production and its operon expression, and slightly down regulated 2,4-DAPG production and its operon expression. Therefore, the crp gene exhibited a significant positive regulation on Prn biosynthesis, a significant negative regulation on Plt biosynythesis, and a small positive regulation on 2,4-DAPGbiosynthesis in P. protegens H78. Related Articles | Metrics

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Protective effect of tenuifolin on HT-22 cells damaged by D-galactose synergistically with Aβ1-42 via PPARγ/PGC-1α signaling pathway LI Congting, ZHU Guoqi, CHEN Yan, QU Yan, BIAN Zhijuan, WANG Xuncui 2023, 40 (3):  16.  doi: 10.3969/j.issn.2095-1736.2023.03.016 Abstract ( 109 )   PDF   Save The AD in vitro model was established by using D-galactose synergistically with Aβ1-42 to induce the damage of HT-22 cells. The purpose of this study was to investigate the role of PPARγ/PGC-1α signaling pathway in D-galactose synergistic Aβ1-42 induced HT-22 cell injury and the intervention mechanism of tenuifolin. MTT assay was used to detect cell viability; Trypan blue dye exclusion assay was used to detect cell death rate; β-galactosidase staining was used to detect cell aging; Mito-Tracker fluorescent labeling to observe mitochondrial damage; Rhodamine 123 staining was applied to detect changes in mitochondrial membrane potential by flow cytometry; Colorimetry was used to detect changes in ultra-trace total ATPase content; Western Blotting was used to detect PPARγ, PGC-1α, COX-2 and NF-κB protein expression. The content of inflammatory factors such as TNF-α, IL-6 were detected by ELISA method. The results showed that compared with the model group, tenuifolin (10, 20, 40 μmol/L) could significantly improve the survival rate of HT-22 cells induced by D-galactose synergistically with Aβ1-42, and reduce the positive rate of β-galactosidase, increase intracellular ATPase activity, prevent the decrease of mitochondrial membrane potential, inhibit the increase of inflammatory factors such as TNF-α, IL-6 levels, down-regulate the expression of NF-κB and COX-2 and up-regulate the expression of PPARγ, PGC-1α in HT-22 cells. The above results suggest that tenuifolin has a protective effect on HT-22 cells damaged by D-galactose synergistically with Aβ1-42 within a certain dose range, and the protective mechanism may be related to up-regulating PPARγ/PGC-1α signaling pathway, enhancing mitochondrial energy metabolism and blocking the inflammatory response. Related Articles | Metrics

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Analysis of recombinant expression and function of Antheraea pernyi ApMLEC LIU Zhichao, GU Suyun, LIU Danmei, FAN Qi, LIU Yubo, ZHANG Jianing, LI Wenli 2023, 40 (3):  22.  doi: 10.3969/j.issn.2095-1736.2023.03.022 Abstract ( 109 )   PDF   Save The study cloned, expressed, purified and performed preliminary functional analysis of Malectin (ApMLEC) from Antheraea pernyi. Based on the known cDNA database of Antheraea pernyi, the ApMLEC gene was cloned by PCR and the sequence information was analyzed by bioinformatics. The gene was ligated to the pET-28a prokaryotic expression vector, and the recombinant protein was purified by Escherichia coli BL21 (DE3) expression system and affinity chromatography. The ability of the protein to bind polysaccharides, agglutinate bacteria and inhibit bacterial growth was investigated. The antiviral activity of the protein was explored by ligating it to the transfer vector pApBacDual-egfp. The results showed that the gene consisted of 798 bases encoding 266 amino acids and the purified recombinant protein had a molecular weight of about 33 ku with the His-tag. The ApMLEC could bind to maltose, lipopolysaccharide and peptidoglycan. It could agglutinate bacteria and inhibit the growth of Escherichia coli and Staphylococcus aereus with a minimum inhibitory mass concentration of 250 μg/mL for both. It also inhibited the replication of Antheraea pernyi nuclear polyhedron viruses. The preliminary functional analysis of ApMLEC suggested that it might play an important role in the natural immunity of Antheraea pernyi, and laid the foundation for future research on the immune system of this species. Related Articles | Metrics

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Antigastric cancer activity of Streptomyces sp. LRE-541 secondary metabolite from Lilium davidii var. unicolor Cotton CHEN Bin, JIANG Kan, GUO Yehong, MA Aiai 2023, 40 (3):  28.  doi: 10.3969/j.issn.2095-1736.2023.03.028 Abstract ( 125 )   PDF   Save n order to study the secondary metabolites of Streptomyces sp. LRE-541 from the roots of Lilium davidii var. unicolor Cotton and its antigastric cancer activity, high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) and other methods were used to isolate, purify and identify the secondary metabolites. The effects of metabolites on cell proliferation, apoptosis and migration of gastric cancer cell HGC-803 were investigated. Two anthraquinones were identified as 4-deoxy-ε-pyrromycinone (1) and epsilon-pyrromycinone (2). The IC50 of compound 1 and compound 2 against gastric cancer cell of HGC-803 were (25.24±1.23) μg/mL and (17.29±2.28) μg/mL, respectively. Under the same treatment, compared with blank control group, the proliferation rate, apoptosis rate and scratch healing rate of cancer cells in 15 and 25 μg/mL of compound 1 and 10 and 20 μg/mL of compound 2 groups were significantly decreased, the differences were statistically significant (P<0.05 or P<0.01). These results indicated that the two compounds could inhibit the proliferation and migration of gastric cancer of HGC-803 cells and promote the apoptosis of gastric cancer cells, which might be potential as anti-gastric cancer drugs or precursors. Related Articles | Metrics

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Molecular modification of raw starch hydrolase AmyZ1 in the enhancement of thermal stability #br# BING Xiaofeng, HE Yu, ZHANG Xuecheng, FANG Zemin, FANG Wei, XIAO Yazhong 2023, 40 (3):  35.  doi: 10.3969/j.issn.2095-1736.2023.03.035 Abstract ( 111 )   PDF   Save Raw starch degrading enzymes are α-amylases with the ability to hydrolyze raw starch. It can degrade raw starch granules below the starch pasting temperature and suitable for cold hydrolysis of starch. The raw starch hydrolase AmyZ1 is derived from a marine microorganism and is not thermally stable. The mock structure of AmyZ1 was obtained by homology modeling. AmyZ1∶ΔTG is a mutant enzyme with deletion of the flexible region was constructed by sentinel mutation. The catalytic property, Ca2+ dependence, and ability to hydrolyze high concentration raw maize starch of the mutant were evaluated. The optimum temperature of AmyZ1∶ΔTG was 45 ℃, and the enzyme activity was maintained above 60% in the range of 35 ℃-55 ℃. The thermal stability of AmyZ1∶ΔTG was improved and the half-lives of 30 ℃ and 35 ℃ reached 18 h and 15 h, which were 10 and 15 times of AmyZ1, respectively. The decreased flexibility of the protein resulted in a decrease in the catalytic efficiency of AmyZ1∶ΔTG. Exogenous Ca2+ has less effect on the catalytic performance of AmyZ1∶ΔTG, but it can improve the thermal stability of AmyZ1∶ΔTG, compared to that of AmyZ1. Using 300 g/L corn raw starch as the substrate, the hydrolysis rate of AmyZ1∶ΔTG was 40%, which was similar to AmyZ1. Related Articles | Metrics

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Screening and degradation characteristics of a BDE-209 degrading bacterium FAN Luosheng, WU Juan, HU Dingfan 2023, 40 (3):  41.  doi: 10.3969/j.issn.2095-1736.2023.03.041 Abstract ( 124 )   PDF   Save To investigate the degradation characteristics of decabromodiphenyl ether (BDE-209) by bacteria, an effective aerobic bacterium for degrading of BDE-209 was isolated from activated sludge and identified as Pseudomonas nitroreducens. The optimal additional carbon sources for the biodegradation of BDE-209 were investigated, and the changes of cell surface characteristics and degradation kinetics at different initial mass concentrations of BDE-209 by P. nitroreducens were explored. The experimental results showed that P. nitroreducens was able to grow with BDE-209 as the sole carbon source. Glucose played a significant role in promoting the biodegradation of BDE-209, and the degradation rate of 10 mg/L BDE-209 could reach 76.2% when the glucose mass concentration was 250 mg/L. The degradation kinetics of BDE-209 was in accordance with pseudo first order reaction kinetic equation with short half-life and fast degradation rate. Moreover, P. nitroreducens had a good tolerance to higher mass concentration of BDE-209. High mass concentration of Cu2+ (≥30 mg/L) inhibited the degradation of BDE-209 and the growth of P.nitroreducens. The high cell surface hydrophobicity of P.nitroreducens made BDE-209 enter the cells more easily. The increase in cell membrane permeability was caused by the stressful effects of BDE-209. The microbial degradation is an effective remediation strategy to remove BDE-209 from the polluted environment, and the effective screening of degrading bacteria from the environment provided more possibilities for BDE-209 biodegradation. Related Articles | Metrics

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creening and identification of cold-tolerant cellulolytic strains of Androsace tapete on Qinghai-Tibet Plateau ZHU Pan, XUE Wenkai, LIU Xing 2023, 40 (3):  48.  doi: 10.3969/j.issn.2095-1736.2023.03.048 Abstract ( 124 )   PDF   Save In order to obtain cold-tolerant cellulolytic strains in the cushion structure of the Androsace tapete, the above-ground parts of the Androsace tapete from three regions with different survival states were used as materials, and the culturable microorganisms were isolated and purified by pure culture method. The cold-tolerant cellulolytic strains were screened by CMC solid medium and CMC-Congo Red solid culture at 4 ℃ and 15 ℃, respectively, and the strains were screened for molecular identification of 16S rRNA and ITS region sequences. The results showed that a total of 52 strains, 14 genera and 32 species of cold-tolerant cellulolytic strains were obtained, including 3 species of bacteria, 9 species of yeast and 20 species of filamentous fungi. The relative cellulase activities of the obtained cold-tolerant cellulolytic strains were high, and the representative strains were Didymella pomorum, Aureobasidium pullulans, Penicillium goetzii and Penicillium griseoroseum. The species composition of cold-tolerant cellulolytic strains differed significantly between individuals from different Androsace tapete and between Phyllospheric and endophytic cellulolytic strains, but there were no significant differences in relative cellulase activity.These cold-tolerant cellulolytic strains can effectively decompose litter in cushion structure, promote carbon cycling, and play an important role in the adaptation of Androsace tapete to extreme environments and perform ecosystem engineer functions, with the more active strains aiming to provide material for industrial applications of biodegradable cellulose in cold regions. Related Articles | Metrics

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Isolation, identification and denitrification characteristics of heterotrophic nitrification aerobic denitrification bacteria from natural rubber processing wastewater HUI Hao, LI Juanjuan, LI Hong, TANG Yanqiong, PENG Shulu, YAN Xiyao, ZHANG Ying, LIU Zhu 2023, 40 (3):  56.  doi: 10.3969/j.issn.2095-1736.2023.03.056 Abstract ( 80 )   PDF   Save In order to provide new strains for the natural rubber wastewater treatment process, strains that can effectively remove ammonia nitrogen were isolated and screened from natural rubber processing wastewater. A strain with the best nitrification ability was seleted by comparing the denitrification capacity, named JD-7. Based on 16S rDNA gene sequencing and morphological characteristics, the strain preliminarily identified as Bacillus sp. strain JD-7 can reduce the ammonia nitrogen mass concentration from the initial 98.24 mg/L down to 8.33 mg/L, the nitrogen removal rate reached 91.25% in 48 hours. The strain showed the ability to remove nitrate and nitrite, and the removal rates were 44.39% and 50.06%, respectively. Then, the nitrification ability of the strain under different environmental conditions (temperature, initial pH value and C/N ratio) was studied by response surface method. The results indicated that the strongest nitrification ability was observed with temperature of 30.35 ℃, initial pH of 7.85 and the C/N ratio of 6.13. The strain was put into different proportions of actual wastewater for small-scale experiments to determine the practical application effect of the strain. Under the optimal conditions, the ammonia nitrogen removal rate of JD-7 to the actual natural rubber processing wastewater can reach 131.48 mg/(L·d). Strain JD-7 has highly efficient denitrification ability, which demonstrated that the strain has great application potential for nitrogen removal in the treatment of natural rubber processing wastewater. Related Articles | Metrics

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Composition and characteristics of intestinal flora of Anserfabalis in different habitats of Shengjin Lake SHI Shuiqin, HE Guangyu, YU Hao, HAN Yu, ZHANG Jingjing, ZHAO Kai 2023, 40 (3):  63.  doi: 10.3969/j.issn.2095-1736.2023.03.063 Abstract ( 125 )   PDF   Save 16S rRNA high-throughput sequencing was used to analyze the intestinal microbial structure and characteristics of Anserfabalis in Yangetou (SLY) and Chi’an (SLC) habitats of Shengjin Lake. The results showed that there was a significant difference in the abundance of intestinal microbiome flora between soybean geese in the two habitats of SLY and SLC in Shengjin Lake (P< 0.05). Firmicutes and Proteobacteria were the dominant bacteria in SLY, and Firmicutes and cyanobacteria were the dominant bacteria in SLC. Lactobacillus (39.5%) was the dominant bacteria in the intestinal flora of Anserfabalis in Shengjin Lake SLY habitat, while norank was the dominant bacteria in the intestinal flora of Anserfabalis in Shengjin Lake and SLC habitat norank_ f__ norank_ o__ Chloroplast (35.3%) and Lactobacillus (19.2%). Based on Bray_ NMDS analysis of Curtis distance matrix showed that the flora in the two habitats showed obvious taxonomic groups. The correlation of intestinal flora network of Anserfabalis in SLC habitat was closer and more complex than that in SLY. In addition, Picrust’s function prediction showed that the cog function annotation results of the intestinal microbiome of Anserfabalis in SLY and SLC habitats mainly included function prediction function, amino acid transport and metabolic replication function, recombination and repair function, signal transduction mechanism function, energy production and conversion function, etc. The results showed that there were significant differences in the composition of intestinal flora of Anserfabalis in Shengjin Lake amphibious habitat at the beginning of winter, and showed unique flora characteristics. The results provided basic data and research direction for the follow-up research and protection of migratory birds in the whole overwintering period. Related Articles | Metrics

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Isolation and identification of porcine epidemic diarrhea virus variant strain and establishment of challenge model JIAO Anqi, GUO Xiaozhen, CHEN Zhi, YU Jiang, YU Kejian, LU Xiaohan, XIN Zhonghao, HAN Xianjie, WU Jiaqiang 2023, 40 (3):  69.  doi: 10.3969/j.issn.2095-1736.2023.03.069 Abstract ( 125 )   PDF   Save Porcine epidemic diarrhea (PED) is an acute contact intestinal infectious disease in pigs caused by the porcine epidemic diarrhea virus (PEDV). In this study, a PEDV strain was isolated and named PEDV-20200946. S protein gene was sequenced and analyzed, and the phylogenetic tree showed that the isolated strain belonged to G2 genotype. The virus titer of this strain was 106.1TCID50/mL determined by Reed-Muench method. Subsequently, the pathogenicity of the isolated strains on piglets was further explored through animal challenge. A total of twelve 20-day-old piglets were divided into three groups on average, and they were named oral group, oral and intramuscular injection group, and control group, respectively. After the viral infection, clinical symptoms were observed, and the feces of each group and the intestines of the affected pigs were collected 72 h later for RT-PCR detection and immunohistochemical analysis. The results showed that piglets in the oral and intramuscular injection group showed the fastest diarrhea occurrence, followed by the oral group, and the control did not have any clinical symptoms. Autopsy examination showed that the intestinal walls of diseased piglets got thinned, their intestines were swollen, and contained a large amount of yellow liquid. Immunohistochemical tests showed that a large number of PEDV positive signals could be detected in the small intestine of piglets in the challenge groups, while the control group showed normal. The piglet challenge model of PEDV-20200946 strain was established, which laid a foundation for in-depth study of the molecular characteristics of PEDV epidemic strains and the development of attenuated vaccines. Related Articles | Metrics

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Effects of hdac8 gene knockout on locomotion capacity of zebrafish LUO Beibei, LUO Juntao, HAN Lijie, HAN Bingshe, ZHANG Junfang 2023, 40 (3):  74.  doi: 10.3969/j.issn.2095-1736.2023.03.074 Abstract ( 116 )   PDF   Save To explore the biological function of thehdac8gene in fish, zebrafish (Danio rerio) was used as a model organism, using CRISPR/Cas9 gene editing technology, the Cas9 target site was designed for the third exon of thehdac8gene, and gRNA was prepared. The gRNA and Cas9 protein were co-microinjected into zebrafish embryos at one-cell stage. After T7E1 endonuclease digestion, sequencing and sequence alignment, it was confirmed that thehdac8gene was successfully knocked out, and F2homozygous mutant zebrafish with a deletion of 41 base pairs in thehdac8gene were obtained. RT-qPCR showed that compared with that of wild-type zebrafish, the expression ofhdac8mRNA was significantly reduced (P<0.0001), while the expression ofhdac1mRNA was compensatively increased (P<0.05), no significant change was detected withhdac3mRNA expression. Western Blot results showed no significant change of H3K27ac, H3K9me3, H3K4me3 and H3K4me1 levels inhdac8-/- zebrafish and muscle tissue. Behavioral tests of wild-type andhdac8-/- zebrafish larvae using the Danio Vision trajectory tracking system were performed, compared with that of wild-type zebrafish larvae, the maximum acceleration ofhdac8-/- zebrafish larvae showed no significant difference, but the total distance, mean velocity, and mobility were all significantly reduced (P<0.000 1), those indicated that knocking out thehdac8gene affected the locomotion capacity of zebrafish larvae. Related Articles | Metrics

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Antimicrobial activity and physicochemical properties analysis of leukocyte antibacterial substances from Phascolosoma esculenta SHU Fengling, LI Tengteng, ZHOU Ruiyao, QIAN Dong, ZHOU Suming 2023, 40 (3):  80.  doi: 10.3969/j.issn.2095-1736.2023.03.080 Abstract ( 112 )   PDF   Save The blood cells of Phascolosoma esculenta were separated by conventional centrifugation. The leukocyte cells in its coelomic fluid were extracted by acetic acid dialysis, and the antibacterial activity of the extracted substances was determined by agar radial diffusion. The antibacterial mechanism of leukocyte antibacterial substances in the coelomic fluid of P. esculenta was analyzed by scanning electron microscopy and the antibacterial substances in the coelomic fluid were preliminarily separated by acid polyacrylamide gel electrophoresis (A-PAGE). The results showed that there was a broad-spectrum antimicrobial activity substance in leukocytes of P. esculenta coelomic fluid, which had broad-spectrum and high-efficiency antimicrobial activity against most Gram-positive bacteria, Gram-negative bacteria and fungi, and the antimicrobial activity of this substance was highly resistant to high temperature. Enzyme activity test showed that antimicrobial substances had certain proteases but no hemolytic characteristics; scanning electron microscope observation showed that the cell walls of bacteria and yeast treated with antibacterial substances were rough, and holes appeared on the surface of some bacteria. The results of A-PAGE electrophoresis separation and agar radial diffusion preliminarily showed that there were two different antimicrobial active substances in the extract of P. esculenta. It was showed that there was a broad-spectrum and high-temperature resistant antibacterial active substance in the coelomic fluid of P. esculenta, which had a certain application prospect. Related Articles | Metrics

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Studies on composition and characteristics of protein particles in bivalve hemolymph plasma XIA Qifeng, LIU Youli, RUAN Ziyan, ZHANG Weiwei, LIN Zhihua, XUE Qinggang 2023, 40 (3):  85.  doi: 10.3969/j.issn.2095-1736.2023.03.085 Abstract ( 105 )   PDF   Save The study focused on the function of plasma protein by analyzing the purified plasma protein in five taxonomic representative bivalves(Crassostrea gigas, Mytilus coruscus, Meretrix meretrix, Sinonovacula constricta, and Scapharca broughtonii). The existence and morphological characteristics of plasma protein particles were proved by transmission electron microscope observation. The result showed that the plasma proteins of the four bivalves formed similar particle morphology with different particle sizes, except Sinonovacula constricta. Then, the constituent of the plasma protein particles and total plasma proteins were identified by PAGE. The results of PAGE showed the plasma protein particles of Crassostrea gigas and Mytilus coruscus were mainly consisted of one or two high-density protein bands, while the plasma protein particles of Meretrix meretrix and Scapharca broughtonii consisted of many low-density protein bands. In addition, we analyzed the metal ion dissociation and binding activity of the purified plasma protein particles of the Pacific oyster. The result showed that Ca2+ carried by natural plasma particles of Crassostrea gigas could be separated by dialysis. The particles could absorb more metal ion in the 50 mg/L group than the 5 mg/L group. Under the same metal ion mass concentration, the binding capacity of protein particles between different metal ions showed diversity (Cd2+> Pb2+>Ca2+> Zn2+). The plasma particles might function as the transporting and storing buffer of metal participate in the metal metabolism process of bivalve mollusks. Related Articles | Metrics

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Cell protein feed was prepared by multi-strain solid state fermentation of corn husk GAO Junjie, YAN Yaping, LI Yongli, LIU Zhanying 2023, 40 (3):  91.  doi: 10.3969/j.issn.2095-1736.2023.03.091 Abstract ( 125 )   PDF   Save The high crude fiber content of corn husk produced by fermentation and starch and sugar industry was used as raw material, and the content of crude fiber in corn husk was reduced and the content of protein in fermentation products was increased by multi-strain solid state fermentation to prepare cell protein feed. Strains were selected for fermentation combinations according to the characteristics of substrates and product. And the effects of strain ratio, inoculation amount, fermentation method, molasses content and nitrogen source type on crude protein, crude fiber and true protein in fermentation products were investigated by single factor experimental design. The results showed that the optimum strain ratio of bacillus subtilis CGMCC 1.7417∶Bacillus subtilis CICC 10090∶Saccharomyces cerevisiae CICC 32236∶candida utilis CGMCC 2.2878 was 1∶1∶2∶2. The Inoculation amount of seed liquid was 15%. The best fermentation method was shallow plate fermentation. The optimum molasses content was 10°Brix. The best nitrogen source was ammonium sulfate. After multi-strain solid state fermentation, the crude protein content of product was 21.38% with an increase rate of 32.47%. The true protein content was 10.77% with an improvement rate of 50.42%. The crude fiber content was 17.78% with a reduction rate of 14.19%. Related Articles | Metrics

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Mechanisms controlling the development of pathogen-induced galls in plants ZHENG Liwen, ZHANG Shenshen, ZHANG Jingtong, GUO Deping 2023, 40 (3):  96.  doi: 10.3969/j.issn.2095-1736.2023.03.096 Abstract ( 125 )   PDF   Save The recent advances of pathogen-plant interactions to form galls are reviewed, which focuses on pathogenesis and influencing factors of gall formation of bacteria, fungi, protozoa, insects and nematodes. The disturbance of the phytohormonal balance and the acquisition of meristematic characteristics by differentiated cells are shared causes of gall formation in host plants. Some pathogens manipulate host plant development by secreting effector proteins, benefiting themselves at the expense of the plant growth and reproduction, which results in the formation of galls. Further research fields are suggested. Related Articles | Metrics

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The roles of bacteria in casing soil during the cultivation of edible fungi XI Liping, HU Chenmenghui, LI Caihong, GUO Ting, BAO Dapeng, YANG Ruiheng 2023, 40 (3):  101.  doi: 10.3969/j.issn.2095-1736.2023.03.101 Abstract ( 103 )   PDF   Save The research progress of the roles of casing soil for the cultivation of edible fungi is reviewed. The species of edible fungi depending on casing soil, the bacterial structure compositions and dynamics in different development stages, biological functions and the molecular mechanism of interactions between them were focused. On the base of the reported achievement, the research prospects of casing soil microorganisms, challenges and solutions are summarized. It provides reference for development promoters and biological control agents to promote the development of edible fungi industry. Related Articles | Metrics

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Green separation and purification of high purity vitamin K2 MA Guoliang, ZHENG Zhiming, WANG Peng, WANG Li, ZHAO Genhai, WANG Han 2023, 40 (3):  107.  doi: 10.3969/j.issn.2095-1736.2023.03.107 Abstract ( 151 )   PDF   Save In order to overcome the shortcomings of high purity Vitamin K2 extraction process, such as large amount of toxic solvent, serious pollution and toxic substance residues, a green separation and purification process of high purity Vitamin K2 was established. Natural oil, methanol, ethanol and other organic reagents were used to extract VK2 from Bacillus natto. The results showed that medium chain triglyceride had the best extraction effect, and the maximum extraction amount was 2.7 mg/g. Seven types of macroporous resins were used to separate VK2 from medium chain triglyceride solvent phase, and the optimal macroporous resin HC-200S was selected by static adsorption and desorption experiments. The dynamic adsorption and desorption process of macroporous resin was optimized, and the dynamic desorption curve of macroporous resin was drawn. The results showed that when the adsorption flow rate of sample solution was 2.0 mL/min, the desorption agent was anhydrous ethanol/butyl acetate mixture solution (1∶2, volume ratio) and the flow rate of desorption agent was 1.0 mL/min, the adsorption and desorption effect of HC-200S macroporous resin on VK2 was the best. At this time, the purity of vitamin K2 was 4 times higher than that of the before purification, reaching 87.8%, and the recovery rate reached 93.1%. VK2 desorption solutions obtained by resin separation and purification were frozen crystallization and solvent volatilization crystallization, respectively, to obtain VK2 crystals with purity of 96.7% and 97.1%. This study provided a method basis for the industrial production and green separation and purification of VK2. Related Articles | Metrics

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Water containment technology and effectiveness assessment of the upper Kulyu river small watershed GENG Ming, LI Yucheng, DOU Yueqin, ZHANG Xuesheng, LI Yonghui, ZHOU Min, SHEN Yu 2023, 40 (3):  113.  doi: 10.3969/j.issn.2095-1736.2023.03.113 Abstract ( 82 )   PDF   Save Based on the current situation of water resources, the nitrogen and phosphorus pollution from soil erosion in the Kulyu river watershed was monitored, and the combination of plant hedge interception, straw mulching, slope transformation combined with organic fertilizer substitution and ditch and pond water hyacinth interception techniques was used for erosion control and clean flow production in forested slopes to promote the circulation of water resources within the system and provide reference for erosion management in the area. The results showed that the soil nutrient content and loss under different land use types in the study area varied significantly, and the nitrogen and phosphorus loss patterns were all dominated by the adsorption state. The losses of total nitrogen (TN) and total phosphorus (TP) were 0.482 t/(km2·a) and 0.117 t/(km2·a) respectively, and the combined measures could effectively reduce 57.32% of suspended solids (SS), 45.97% of TN and 38.97% of TP on forest slopes. TN 45.97% and TP 38.93% can increase soil organic matter by 50.06% and improve soil water content by 39.94%. The highest soil nutrient content and loss in the economic forest land, and the increase of paddy land use may improve soil erosion in the area. The combined measures effectively cut sediment erosion, TN, TP and SS content caused by soil erosion and improve the soil and increase water retention capacity. Related Articles | Metrics

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Gene cloning construction method for undergraduate genetic engineering experimental course LU Yingying, FAN Weikang, WEI Youheng 2023, 40 (3):  119.  doi: 10.3969/j.issn.2095-1736.2023.03.119 Abstract ( 163 )   PDF   Save The ccdB gene was introduced, using the Gateway system, to the vector to improve the efficiency of clone construction. The Escherichia coli transfected with vectors containing ccdB could not grow to form clones because the ccdB is toxic to it. Thus, this strategy avoided the false positive clone formation and made the plasmid construct much more convenient. Through comparison of the different strategies of clone construction, this class made students understand more on genetic engineering-related processes such as enzyme digestion, recombination, ligation. This method is suitable not only for the experimental course but also for cloning construction in future research. Related Articles | Metrics

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Exploration and practice of ideological and political education in synthetic biology curriculum WANG Dongmei, HONG Jiong 2023, 40 (3):  124.  doi: 10.3969/j.issn.2095-1736.2023.03.124 Abstract ( 135 )   PDF   Save 根据合成生物学课程的教学内容践行课程思政教学，明确教学目标，通过科学设计和教学实施，将课程中蕴含的思政元素有机融入相关的教学内容。注重学思结合，知行统一，实现对学生的正确价值观的塑造、知识的传授和能力的培养，从而激发学生科技报国的家国情怀和使命担当。在课程思政实施过程中，教师课程思政建设的意识和能力也得到了提升，加强了自身德育修养，打造了师生双赢的局面，为构建大思政格局作出初步的探索和实践。 Related Articles | Metrics

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The role of professional practice teaching in the cultivation of interdisciplinary academic postgraduates in agricultural sciences #br# SU Shiping, LI Xilei, ZHANG Jun, WEI Zhong 2023, 40 (3):  128.  doi: 10.3969/j.issn.2095-1736.2023.03.128 Abstract ( 124 )   PDF   Save In order to solve the shortcomings of weak theoretical knowledge and limited professional scientific research thinking of interdisciplinary academic graduate students, it is imperative to explore a new training mode for postgraduate students. Through the investigation and analysis of the effect of professional practice teaching of interdisciplinary students majoring in aquaculture, it was found that professional practice teaching is a necessary link in the cultivation of interdisciplinary graduate students majoring in aquaculture. Professional practice teaching is an effective way to quickly make up for the lack of professional knowledge and professional skills of interdisciplinary students. It is not only a shortcut to expand scientific research thinking, but also an important help to improve professional innovation ability. Therefore, professional practice teaching should be a essential for the cultivation of interdisciplinary postgraduate students in aquaculture. Related Articles | Metrics