Tao Zhong , Zhirong Wang , Muying Du
2021, 61(7):1771-1785. DOI: 10.13343/j.cnki.wsxb.20200420
Abstract:With the increasingly prominent disadvantages of chemical fungicides, biological control has gradually attracted more attention for controlling disease of postharvest fruits and vegetables. Among biological control agents, volatile organic compounds (VOCs) produced by different microorganisms can significantly inhibit the growth of various pathogens, and effectively control postharvest fruit and vegetable decay. Thus, VOCs synthetized by microorganisms are favored due to their safety, effectiveness, environmental harmlessness, easy degradation and no residue. Therefore, we review here the diversity of microorganisms with the ability to produce VOCs, the diversity of VOCs from microorganisms, the antifungal activities of VOCs and their possible related mechanisms responsible for the biocontrol effect, to provide an basis to develop biocontrol agents.
Wanyu Zhu , Liuyang Shi , Wei Zhao , Zhiyong Huang , Xingbiao Wang
2021, 61(7):1786-1798. DOI: 10.13343/j.cnki.wsxb.20200434
Abstract:Aerobic denitrification is an aerobic process to convert NO3--N into N2. Aerobic denitrifiers not only denitrify well, but also survive under extreme conditions such as to tolerate a variety of heavy metals. This paper summarizes the effects of Cr(VI), Cu(Ⅱ), Cd(Ⅱ) on the denitrification efficiency of aerobic denitrifiers. At the same time, the mechanisms of aerobic denitrifiers to tolerate or remove different heavy metals are summarized. The application potential of aerobic denitrifiers in industrial wastewater is analyzed, and the future research direction of aerobic denitrifiers is proposed, to provide comprehensive theoretical understanding and technical support for the treatment of nitrogen and heavy metals pollution in industrial water.
Yanni Zhao , Yue Li , Jing An , Huan Liu , Xiyue Wang
2021, 61(7):1799-1815. DOI: 10.13343/j.cnki.wsxb.20200451
Abstract:Metabolomics has become one of the most important areas in systems biology, to qualitatively and quantitatively analyze all endogenous metabolites and reveal the relationship between physiological/pathological changes or environmental perturbation and biological metabolism. Metabolomics has the characteristics of high sensitivity, wide selection range and fast analysis speed, and so it plays an increasing role in the microalgae studies. In this review, we summarize the research process, analysis methods, development trends and challenges of metabolomics in microalgae researches, to provide new ideas and strategies for bioenergy utilization, environmental protection, and high-value bioproducts of microalgae.
Zhaoxi Liu , Lushan Wang , Min Chen
2021, 61(7):1816-1828. DOI: 10.13343/j.cnki.wsxb.20200478
Abstract:The gut microbiota is a changing ecosystem, containing trillions of bacteria, continuously shaped by many factors, such as dietary habits, seasonality, lifestyle, stress, antibiotics use, or diseases. Diet is the key determinant of the microbiota configuration, through modulation of the abundance of specific species and their individual or collective functions. Most complex plant polysaccharides from diet are not digested by humans and enter the colon as a potential nutrient source for the microbiota. Gut microbiota can convert these undigestible polysaccharides into short-chain fatty acids (SCFAs). Besides, SCFAs are likely to have broad impacts on various aspects of host physiology. Dietary fibers interact directly with gut microbes and lead to the production of key metabolites such as short-chain fatty acids. Dietary fibers can be considered key ancestral compounds that preserve gut ecology, especially regulating macronutrients and host physiology. Here we summarize the composition of intestinal symbiotic bacteria, the utilization of polysaccharides entering the intestinal tract, and the potential impact of metabolites on human health.
Manyu Jin , Jinpeng Li , Li Yi , Yang Wang
2021, 61(7):1829-1838. DOI: 10.13343/j.cnki.wsxb.20200479
Abstract:Streptococcus suis is a human-zoonotic infectious disease that seriously affects the pig industry and human health in various countries. It can cause septicemia, arthritis, meningitis and other diseases, thus causing huge economic losses. The biofilm formation is the main cause of increasing pathogenicity and drug resistance of S. suis. It is of great significance to understand and master the biofilm formation and drug resistance mechanism of S. suis, and to find the effective method of removing biofilm for the prevention and treatment of S. suis. This review updates the latest scientific knowledge about the formation and drug resistance mechanism of S. suis biofilm, focusing on biochemical factors, physiological factors, molecular mechanism and environmental changes, etc., to summarize and discuss the drug resistance mechanism of S. suis biofilm, to provide a scientific theoretical basis for the prevention and treatment of the disease.
Xing Li , Yixin Ou , Qianjin Kang , Linquan Bai , Zixin Deng
2021, 61(7):1839-1855. DOI: 10.13343/j.cnki.wsxb.20200503
Abstract:Moenomycins produced by Streptomyces are phosphoglycolipid antibiotics, and inhibit the active sites of peptidoglycan glycosyltransferases involved in the biosynthesis of Gram-positive bacterial cell wall. Moenomycins show a strong biological activity, and possess important research value and development potential. This paper systematically reviews the advances in chemical biology of moenomycins, including the chemical structures, bioactive mechanisms, latest development of biosynthesis, efflux mechanisms and new derivatives of moenomycins. Moreover, the research bottleneck in chemical biology of moenomycins is referred aiming to promote the research and development of high-activity phosphoglycolipid drugs for clinic and industry.
Yanting Niu , Shuaitao Wang , Juanli Cheng , Jinshui Lin
2021, 61(7):1856-1872. DOI: 10.13343/j.cnki.wsxb.20200515
Abstract:As a structural, catalytic, and regulatory component, zinc plays a key role in many cellular processes. It is also necessary for the growth of pathogenic microorganisms. It is not only involved in microbial pathogen metabolism and various virulence play, but also necessary for microbial pathogen infection and colonization in the host. When Pseudomonas aeruginosa infects the host to exert its virulence, the host will adopt the strategy of nutritional immunity to limit the concentration of free zinc ions in the internal environment and inhibit the infection and colonization of the pathogen. On the contrary, P. aeruginosa overcomes the host's nutritional immune defenses through its own zinc uptake systems. This review focuses on the three known zinc uptake systems (ZnuABC, HmtA and CntRLMN) and zinc uptake regulator (Zur) in P. aeruginosa, and further analyzes other potential zinc uptake pathways. The important roles of P. aeruginosa zinc uptake systems in host virulence and nutritional immune defense are also discussed. A systematic summary of the P. aeruginosa zinc uptake pathways is aimed at providing guidance for the development of new anti-P. aeruginosa drugs targeted zinc uptake systems.
Bing Wang , Hongxia Wu , Hua-Ji Qiu , Yuan Sun
2021, 61(7):1873-1881. DOI: 10.13343/j.cnki.wsxb.20200521
Abstract:Several viruses replicate and assemble in specific intracellular compartments, known as viral factories. Currently, with the continuous improvement of the research level, several studies have revealed the structure and formation of the viral factories to some extent. After entry, viruses can recruit cell and viral components in which they assemble and mature. Cell membranes and cytoskeleton participate in the biogenesis of viral factories, and some of them must be supplied with energy by mitochondria. Besides characteristics of viral factories mentioned above, the structure and pattern of them will continue to change as the viruses replicate. This article reviews the structure, organelle recruitment, structural transformation and movement of macromolecular complexes.
Pingping Zhou , Tao Wang , Yuan Sun , Hua-Ji Qiu
2021, 61(7):1882-1895. DOI: 10.13343/j.cnki.wsxb.20200531
Abstract:The recognition of microbial nucleic acids is a major mechanism by which the immune system detects pathogenic microorganisms. Cyclic guanosine phosphate adenosine synthase is a cytoplasmic DNA sensor that activates the CGAS-STING pathway after sensing pathogenic DNA. The cGAS-STING pathway not only mediates innate immune response against infections by a large variety of DNA-containing pathogens, but also senses tumor-derived DNA to generate intrinsic antitumor immunity. However, aberrant activation of the cGAS-STING pathway by autologous DNA can also lead to autoimmune and inflammatory diseases. The paper reviews the cGAS-STING signaling pathway and its regulation and functions in antiviral innate immunity, and expounds the role of the cGAS-STING signaling pathway in defensing viral infections and diseases.
Yanjiao Du , Yao Tian , Zhixiao Yuan , Mingyao Yang
2021, 61(7):1896-1909. DOI: 10.13343/j.cnki.wsxb.20200551
Abstract:It is believed that symbiotic bacteria in the gut form an important part of animals, which play a significant role in the growth, development and health of the host. In recent years, it has attracted more attention on a national and international level. Drosophila melanogaster is an excellent model for studying the function of intestinal flora and has made important progress in the relationship between symbiotic gut bacteria and their host. In this paper, we first summarized the composition and characteristics of intestinal microbes in Drosophila, we then reviewed the roles of symbiotic fly gut bacteria on the host growth and development, nutrition and metabolism, behavioral response, longevity, immunity and disease. This will provide some theoretical rationales and new ideas for the study of the function of the gut symbiotic bacteria and the gut health in human.
Meng Yuan , Wen Zhang , Pengwei Hu , Muhua Yu , Hui Chen , Li Xu , Yuan Gao , Bingqing Zhu , Yongxiang Duan , Zhujun Shao
2021, 61(7):1910-1919. DOI: 10.13343/j.cnki.wsxb.20200376
Abstract:[Objective] To find a suitable molecular typing method for Neisseria meningitides. [Methods] We used 125 presentative N. meningitidis strains to develop a new typing method, named core genome single nucleotide polymorphism (SNP) typing, based on the whole genome sequencing. This method was compared to the MLST and cgMLST typing that have been published on pubMLST website. [Results] The genotyping results of 125 N. meningitides strains isolates were consistent between the core genome SNP typing and egMLST, both of which are significantly better than MLST. The core genome SNP typing identified the population structure and defined the clonal complexes. Comparatively, cgMLST could type any strain but cannot define or assign its clonal complex. [Conclusion] Core genome SNP typing showed consistent results with cgMLST and both methods are significantly better than MLST.
Rouke Chen , Yongxin Lv , Huanhuan Zhang , Qinghao Song , Jun Xu
2021, 61(7):1920-1932. DOI: 10.13343/j.cnki.wsxb.20200384
Abstract:[Objective] Pyrococcus yayanosii A1, with its optimum growth condition at 98℃ and 5.2×104 Pa, was a laboratory mutant strain used in the studies of environmental adaptation mechanisms in a group of piezophilic hyperthermophilic archaea in Thermococcaceae. In this study, we established a new genetic tool for P. yayanosii A1, to knock down gene expression based on an endogenous active type Ⅲ-B CRISPR-Cas system.[Methods] The mini-CRISPR cluster was consisted the repeat sequences from endogenous CRISPR arrays Group I and a protospacer from a putative amylase gene (PYCH_13690). We inserted an artificial mini-CRISPR cluster into the shuttle vector pLMOShhp1, with the overexpression of the HMG-CoA (hydroxy methylglutaryl coenzyme A) reductase gene controlled by a constitutive promoter Pgdh, which conferred simvastatin resistance. And the mini-CRISPR cluster transformed crRNA, which guided the Cmr complex cut target mRNA. [Results] The ratio of mRNA cleavage of a high hydrostatic pressure inducible promoter Phhp was 33% at 5.2×104 Pa and 50% at 1.0×102 Pa, while the cleavage of constitutive promoter Phmtb was 42% at 5.2×104 Pa and 76% at 1.0×102 Pa. As a proof, the gene knockdown mutant degraded less starch than its parental strain A1 in vivo. [Conclusion] Thus, we successfully constructed a gene knockdown system based on type Ⅲ-B CRISPR-Cas system in P. yayanosii, which could be used in the genetic studies targeting essential genes in piezophilic hyperthermophiles.
2021, 61(7):1933-1944. DOI: 10.13343/j.cnki.wsxb.20200388
Abstract:[Objective] Aimed to reveal the community compositions of nitrifiers and its response to pH in typical agricultural upland purple soils. [Methods] Metagenomics was used to investigate the abundances and communities of soil nitrifiers, including ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB) and complete ammonia oxidizers (Comammox) in three purple soils that developed from the same parent material but varied in pH. [Results] The abundances of nitrifiers accounted for 2.130%
Lili Gao , Congcong Wang , Fan Yang , Weijun Cao , Xiangle Zhang , Xiangtao Liu , Zixiang Zhu , Haixue Zheng
2021, 61(7):1945-1956. DOI: 10.13343/j.cnki.wsxb.20200404
Abstract:[Objective] Generating ribosomal protein SA (RPSA) knockout baby hamster syrian kidney (BHK21) cells using the clustered regularly interspaced short palindromic repeats/Cas 9 nuclease (CRISPR/Cas9) gene editing technology, and evaluation of the regulatory effect of RPSA on Senecavirus A (SVA) replication. [Methods] We designed 4 pairs of guide RNAs (sgRNA). After screening, the PX330-RPSA-sgRNA2 recombinant plasmid was used for construction of RPSA gene knockout cell line. PX330-RPSA-sgRNA2 was transfected into BHK21 cells, and the monoclonal cell was screened by limited dilution method. The knockout of RPSA was evaluated by Western blotting. The replicative difference of SVA in the wildtype and RPSA knockout cells was investigated by Western blotting and qPCR analysis.[Results] The Western blotting and Sanger sequencing results showed that RPSA within the BHK21 cell line was knocked out. We further investigated the replication of SVA in the RPSA knockout cells which showed that SVA replication was dramatically decreased in RPSA knockout cells comparing with that in the wildtype cells. [Conclusion] The RPSA gene knockout BHK21 cell line was successfully constructed, and RPSA played an important role during SVA replication. The constructed cell line will be a useful tool for exploiting RPSA functions.
Zhenxing Yang , Zhanhong Li , Defang Liao , Xiang Gao , Zhongyan Hu , Jiarui Xie , Huachun Li , Heng Yang
2021, 61(7):1957-1970. DOI: 10.13343/j.cnki.wsxb.20200408
Abstract:[Objective] Deepen our understanding about the diversity of epidemic arboviruses of Yunnan Province [Methods] Blood samples regularly collected form sentinel cattle placed in Jinghong city of Yunnan Province, were inoculated on cells for arboviruses isolation. The isolated virus strain was initially identified by RT-PCR, viral genomic agarose gel electrophoresis (AGE) and electron microscope (TM). Full-length segment 2 (Seg-2) and segment 3 (Seg-3) of the isolated virus were sequenced and the virus classification was conducted by phylogenetic tree construction. The infection kinetics of the isolated virus on the sentinel cattle was retrospectively traced back by qRT-PCR and serum neutralization test.[Results] An unidentified virus strain, causing significant cytopathic effect on BHK-21 cells, was isolated from the blood sample of sentinel cattle. The genome of isolated virus is composed of double stranded RNA showing "3-3-3" migration pattern by AGE analysis. TM observation revealed that the virus particles exhibited typical characteristics of Orbivirus with ring-shaped structure about 70 nm in diameter. Seg-2 of the isolated virus encoding the conserved T2 protein of Orbivirus, showed the closest relationship with Mobuck virus with nucleic acid (nt) and amino acid (aa) sequence identities of 72.8% and 84.0% respectively. Meanwhile, Seeg-3 of the isolated virus encoding Orbivirus serotype decisive OC1 protein, only showed 60.2% (nt) and 56.5% (aa) sequences identity with Mobuck virus. Furthermore, on the phylogenetic tree of T2 and OC1, the isolated virus formed a distinctive branch from Mobuck virus. Retrospective tracing results of the virus infected cattle showed viral RNA lasted in the blood for 17 weeks until supervision terminated. Neutralization antibodies (antibody titer 1:14) were detected one week after virus infection, peaked at the 9th week (antibody titer 1:226) and remained at a high level (antibody titer 1:113) to the end of monitoring. [Conclusion] We reported here, for the first time, the isolation and infection kinetics of a novel Mobuck virus strain isolated from sentinel cattle in Yunnan Province. The results of this study enriched our knowledge about orbiviruses in China, and laid a foundation for the diagnosis, epidemiology and pathogenicity of this novel virus.
Tianchen Huang , Jianhua Yang , Zijing Tang , Le Gao , Dongyuan Zhang , Ying Hou , Leilei Zhu
2021, 61(7):1971-1982. DOI: 10.13343/j.cnki.wsxb.20200444
Abstract:[Objective] To study the synergistic degradation of cellulose by lytic polysaccharide monooxygenase HcLPMO and cellulase. [Methods] We used E. coli for heterologous expression of HcLPMO and studied the influences of various conditions on the activity detection of LPMOs with AmplexTM Ultra Red as fluorogenic substrate. Subsequently, we studied the synergistic degradation of avicel and other biomass substrates with different proportion of HcLPMO and cellulase.[Results] We found the optimal filling liquid volume was 20% and the optimal induction temperature was 20℃ for HcLPMO expression. The results of activity determination show that HcLPMO had activity only when it was combined with copper ions. The optimal concentration of sodium ascorbate was 10-4 mol/L. We also found that the concentration of AmplexTM Ultra Red and horseradish peroxidase had little effect on the detection of enzyme activity. For the synergistic degradation of avicel by HcLPMO and cellulase, we found the optimal ratio of HcLPMO to cellulase was 2:3, and the yield of glucose increased by 99.48% compared with cellulase alone. In addition, for a variety of biomass substrates, HcLPMO and cellulase had better synergistic degradation efficiency on steam exploded straw and microcrystalline cellulose from which the yield of glucose increased by 63.81% and 59.43%, respectively, compared with using cellulase alone. For alkali treated corn cob and cassava residue, the yield of glucose only increased by 35.41% and 11.06%, respectively.[Conclusion] The appropriate ratio of HcLPMO and cellulase can effectively improve the efficiency of enzymatic degradation of cellulose, and substrate pretreatment is very helpful for the synergistic degradation of lignocellulose by HcLPMO and cellulase.
Guangzheng He , Qingqing Han , Xizuo Zhai , Shujing Xu , Jiansong Ju
2021, 61(7):1983-1996. DOI: 10.13343/j.cnki.wsxb.20200453
Abstract:[Objective] The N-terminal domain of alanine racemase from Bacillus pseudofirmus OF4 was recombined with the alanine racemase C-terminal domains of many different species to explore the function of C-terminal domain. [Methods] The recombinant genes of alanine racemase were constructed by the gene splicing and expressed in E. coli BL21(DE3). The recombinant proteins were purified by affinity chromatography. D-amino acid oxidase coupling method was used to detect the enzymatic properties of the proteins, while the polymerization states and kinetic parameters of recombinant enzymes were analyzed by the molecular sieve and high-performance liquid chromatography (HPLC). [Results] The recombinant proteins were expressed and purified successfully. OF4TtDadX240c had a catalytic activity which was 60.54% of OF4DadX, whereas other recombinant enzymes lost their activities. The catalytic kinetics showed that the catalytic rate (Vmax/Km) of OF4TtDadX240c decreased about 10-fold, but its stability improved significantly. The half-life of OF4TtDadX240c had about a 5-fold prolongation than OF4DadX, and a significantly improved heat resistance. The results of the molecular sieve showed that OF4DadX, OF4TMDadX226c and OF4TtDadX240c were dimers and other proteins were monomers. However, OF4TMDadX226c lost its activity which could be attributed to the shift of the catalytic active center that failed to form the proton transfer. [Conclusion] The C-terminal folding domain of alanine racemase plays an important role in racemase dimerization, stability and catalytic function.
Yunzhang Ding , Feng Ni , Xin Zhao , Yijia Zhang , Donghua Jiang
2021, 61(7):1997-2006. DOI: 10.13343/j.cnki.wsxb.20200473
Abstract:[Objective] The active components of intracellular secondary metabolites from Monascus purpureus Mp-21 were studied. [Methods] The intracellular secondary metabolites were separated and purified by a variety of chromatographic separation methods, and the structure of the compounds was analyzed and identified using a variety of chromatographic data. Monomeric compounds were tested for antioxidant activity and hypoglycemia-related enzyme inhibitory activity. [Results] Three active compounds, namely baicalein, genistein and glycitein were isolated and identified. Baicalein was first discovered from Monascaceae whereas genistein and glycitein were first discovered from Monascus purpureus. In vitro antioxidant activity test and hypoglycemic- related enzyme activity test, baicalein had strong scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH), O2- and OH- radical, and strong inhibitory effect on α-glucosidase and α-amylase, with IC50 of 5.67, 36.40, 17.46, 30.94, 430.93 μg/mL, respectively. [Conclusion] Secondary metabolites from Monascus purpureus Mp-21 have the potential to be developed into functional food such as antioxidant and hypoglycemic agents.
Hongmei Zeng , Wei Zhao , Xiang Wang , Shiqiang Yan , Zexiao Yang , Yan Luo , Jianguo Chen , Yin Wang , Xueping Yao
2021, 61(7):2007-2017. DOI: 10.13343/j.cnki.wsxb.20200482
Abstract:[Objective] In order to investigate a forest musk deer's death, we collected the musk deer's lung tissue to isolate and identify bacteria. [Methods] We identified the strains by bacterial isolation and purification, biochemical test and 16S rRNA sequence analysis. Then, we designed the whole genome and cytolethal distendin toxin subunit B analysis to learn the drug resistance and pathogenicity of the isolated strain. [Results] First, a gram-negative strain was isolated from the lungs of the musk deer, and identified as Bordetella trematum and named as ZL0001. It was an intracellular parasitic bacterium containing cytolethal distendin toxin subunit B. According to drug sensitivity test, the isolate was sensitive to ampicillin but resistant to amtriaxone. The average nucleotide identity values of the strain compared to other Bordetella trematum were >97%, and the genome size was 4350644 bp. In the whole-genome, 22 drug-resistant genes were found. Moreover, the genome contains 63 virulence genes that participated in many processes, such as iron intake. [Conclusion] Bordetella trematum was isolated in the respiratory tract of forest musk, and proved as intracellular bacterium.
Xinjie Qian , Yihao Li , Hang Zeng , Hanjie Yin , Yuxin Wang , Haosheng Huang , Qianwen Gong , Dezhi Li , Feng Xue , Fang Tang , Jianjun Dai
2021, 61(7):2018-2030. DOI: 10.13343/j.cnki.wsxb.20200486
Abstract:[Objective] Analyzing the biological characteristics of two enteroaggregating Escherichia coli (EAEC) CVCC232 phages PNJ1809-11 and PNJ1809-13, and evaluating their bactericidal effects as environmental disinfectants. [Methods] We observed the morphology of PNJ1809-11 and PNJ1809-13 under a transmission electron microscope, analysed their biological characteristics, including the host spectrum, optimal multiplicity of infection, one-step growth curve, and tolerance to pH and temperature, also compared the sterilization efficiency of atomized and sprayed phages. We next determined the bactericidal effect of the sprayed phage in a simulated livestock farm environment as well as the effect of the phages on the biofilm disruption of the host bacteria. At last we tested the tolerance of the two phages to the environment of simulated livestock farm and the mutation frequency of phage-resistant strains. [Results] The results of electron microscope observation showed that phages PNJ1809-11 and PNJ1809-13 both belong to Myoviridae phages. PNJ1809-11 and PNJ1809-13 could lyse 155 and 46 Escherichia coli strains, respectively. Biological assays showed that the MOI of the two phages are both 10; the optimal pH of them are both 7; compared with PNJ1809-13, PNJ1809-11 showed better thermal stability. In the simulated closed device, the sterilization efficiency of spryed and atomized PNJ1809-11 and PNJ1809-13 on the host bacteria was as high as 99%; the sterilization efficiency on the surface of artificially contaminated feces was also higher than 99%. The lysis efficiency of PNJ1809-11, PNJ1809-13 and their mixture (phage cocktail) against biofilm of CVCC232 were 78%, 30% and 83% respectively. Phage PNJ1809-11 had better tolerance than PNJ1809-13 to the temperature, fecal pH and sunlight of simulated livestock farm. The mutation frequency of phage-resistant strains was 2.5×10-3 and 1.0×10-3 respectively. [Conclusion] In summary, phage PNJ1809-11 was more tolerant to the environment, and the phage cocktail showed higher lysis effect on biofilm, which suggested that sprayed phage PNJ1809-11 or the cocktail of PNJ1809-11 and PNJ1809-13 had the potential as an environmental disinfectant.
Lei Wang , Xi Cao , Guofang Wu , Yongzhong Chen , Ru Meng , Ying Wu , Shuqin Wang , Deqing Yan , Ke Zhang , Chengtu Zhang
2021, 61(7):2031-2042. DOI: 10.13343/j.cnki.wsxb.20200496
Abstract:[Objective] To explore the effect of adding compound probiotics on the growth performance, blood physiological and biochemical indexes and gut microbiota composition of beef cattle. [Methods] Eighteen crossbred 1 generation of Simmental and Holstein cattle were selected in Qinghai area, and randomly divided into two groups according to the principle of similar average weight of each group (n=9). The Y1 group was fed with compound probiotics containing Bacillus licheniformis, Bacillus subtilis and Saccharomyces cerevisiae.[Results] The daily increase in chest circumference was significantly increased in Y1 group (P>0.05); the concentration of cortisol was significantly higher in the Y1 group (P<0.05), and the concentration of high density liptein cholesterol, low density liptein cholesterol and total cholesterol was significantly lower in the Y1 group (P<0.05). Analysis the gut microbiota by 16S rRNA gene sequencing, there was not significant difference in Alpha diversity between two group (P>0.05), Beta diversity significantly differences of two group (P<0.05). The relative abundance of Tenericutes, Alisipes and Ruminococcaceae were significantly higher than that of the Y2 group (P<0.05), but the relative abundance of Alloprevotella was significantly lower than that of the Y2 group (P<0.05). There was not significant difference in the detected Bacillus sp.. Interestingly, the Y1 group reduced the abundance of E. coli in the gut. [Conclusion] Feeding compound probiotics can effectively reduce the synthesis of serum cholesterol and inhibit the reproduction of harmful microbial, which provides a theoretical basis for the healthy breeding of beef cattle.
Zhihong Zhang , Jiao Yang , Haipeng Zhang , Youhong Zhong , Peng Wang
2021, 61(7):2043-2052. DOI: 10.13343/j.cnki.wsxb.20200502
Abstract:[Objective] To isolate Staphylococcus aureus bacteriophage from hospital sewage, observe its morphology, study its host range, biological and genetic characteristics, to lay an experimental foundation for the clinical application of bacteriophage. [Methods] Using Staphylococcus aureus ATCC25923 as the host bacterium to isolate and purify bacteriophage from hospital sewage by the double-layer agar plate assay. Observing bacteriophage morphology by transmission electron microscope, determining its optimal multiplicity of infection (optimal MOI), one-step growth curve and host range. Sequencing the whole genome, analyzing gene structure and annotating gene function. [Results] A strain of Staphylococcus aureus bacteriophage (named vB_SauH_SAP1) was isolated from hospital sewage. vB_SauH_SAP1 has a high host specificity and can only lyse 10 strains of clinical isolates of Staphylococcus (a total of 37 strains). Transmission electron microscopy observation shows an icosahedron head and a contractile tail, which belongs to Myoviridae family. The optimal MOI was 0.1, the latent phase was 10 min and lysis period was 20 min. The genome was 143375 bp in length, with a G+C content of 30.2%, encoding 226 ORFs. No known virulence-related gene or antibiotic resistance gene has been predicted. Its genome has high homology with Kayvirus Staphylococcus bacteriophages.[Conclusion] A new Kayvirus Staphylococcus aureus bacteriophage with potential application value was isolated and characterized.
Raorao Huo , Qinmiao Sun , Xiaona Wang
2021, 61(7):2053-2064. DOI: 10.13343/j.cnki.wsxb.20200535
Abstract:[Objective] In this study, we used high throughput sequencing (RNA-Seq) to investigate the gene expression profiles in human monocyte-derived macrophages (THP-1) before and post-infection of vaccinia virus (VACV).[Methods] We analyzed differentially expressed genes in human macrophages with and without vaccinia virus infection by RNA-seq and performed the KEGG, GO, and STRING network analysis to study the immune-related signal alterations during infection.[Results] A total of 4796 genes were differentially expressed (2416 genes upregulated and 2380 genes downregulated) of VACV treatment THP-1 versus control. Further KEGG enrichment analysis shows that differential genes expression in VACV treatment THP-1 cells were mainly involved in metabolism, signal transduction, immune system, infectious diseases and other pathways. Gene Ontology (GO) functional annotation indicated that these genes were mainly enriched on cell function regulation, metabolism, immune regulation and other life processes. The STRING online database analysis showed that JUN, CHUK, IL1B, PYCARD protein were higher in the infected THP-1 cells. [Conclusion] Vaccinia virus can induce the differential expression of various genes in host cells, and multiple biological processes. We conducted in-depth analysis of immune-related signal pathways, and found the C-type lectin receptor-, NOD-like receptor-, and Toll-like receptor- signaling pathway are involved in inflammation responses induced by vaccinia virus infection. These results provide new insights not only in exploring the mechanism of interaction between vaccinia virus and host, but also in applying it in treatments of infectious diseases and cancers.
Hong Sun , Lijuan Chai , Zhenming Lu , Xiaojuan Zhang , Jinbo Ji , Jinsong Shi , Zhenghong Xu
2021, 61(7):2065-2076. DOI: 10.13343/j.cnki.wsxb.20200537
Abstract:[Objective] To better explain the metabolic mechanism of microbial community during Zhenjiang vinegar fermentation, we studied the interaction between Acetobacter and Lactobacillus, the key functional microorganisms during multispecies solid-state acetic acid fermentation. [Methods] Here, two strains of Acetobacter and eight strains of Lactobacillus isolated from vinegar fermentation culture, namely, Acetobacter pasteurianus G3-2, A. pomorum G15-6, Lactobacillus paracasei E1-1, L. helveticus M3-1, L. reuteri GE7-1, L. plantarum M10-1, L. fermentum M10-3, L. casei E10-1, L. pontis M17-5, L. hilgardii M3-4, were selected for microbial growth and metabolism analysis in monoculture and coculture fermentation. We compared the differences of interaction types between in vitro fermentation and in situ fermentation, then GC-MS was used to analyze the effects of interaction on the flavor of Zhenjiang vinegar. [Results] Synergistic effect between A. pasteurianus G3-2 and L. helveticus M3-1, L. plantarum M10-1, L. pontis M17-5 and L. reuteri GE7-1 in vitro fermentation and in situ fermentation was identified. Negative effect between A. pomorum G15-6 and L. paracasei E1-1, however, A. pomorum G15-6 showed different effects on L. plantarum M10-1, L. pontis M17-5 and L. reuteri GE7-1 in vitro fermentation and in situ fermentation. Coculture of A. pasteurianus G3-2 and L. helveticus M3-1, L. reuteri GE7-1 showed better performance in 2,3-butanedione, valeric acid, ethyl acetate and octyl formate production than monoculture, and the yield of 2,3-butanedione increased from none detected to 9.87 mg/L and 14.28 mg/L. [Conclusion] The interaction between Lactobacillus and Acetobacter in Cupei can affect the changes of main metabolites and volatile substances. This work provides a theoretical basis for in-depth analysis of the brewing mechanism of Zhenjiang vinegar, lays the foundation for rational regulation of the microbial community and improving the flavor and quality of Zhenjiang vinegar.
Liqin Wu , Suling Yang , Limei Qi , Guijun Liu , Haike Gu
2021, 61(7):2077-2090. DOI: 10.13343/j.cnki.wsxb.20200541
Abstract:Aureobasidium spp. are cosmopolitan yeast-like fungi and popularly known as black yeasts due to their melanin production. Many strains of Aureobasidium spp. are found to secreted extracellular lipids as liamocins. Liamocins are surface active and has promising anticancer and antibacterial activities. This paper reviewed the variety of liamocin-secreting Aureobasidium spp. and the factors that affecting liamocins production. It also summarized the research progress of the biosynthetic pathway of liamocins. Also some further research of liamocins production by Aureobasidium spp. was recommended.
Yuqin Xi , Jinxia Lai , Mingxu Zhang , Chunyan Ren , Weibao Kong , Lingyun Jia
2021, 61(7):2091-2100. DOI: 10.13343/j.cnki.wsxb.20200547
Abstract:[Objective] In order to explore the effect of heavy metals on the growth of freshwater green algae. [Methods] Chlorella vulgaris, which has been taken as an obvious indicator of water quality detection, was selected as the experimental material. CdCl2·2H2O and CrCl3·7H2O provided heavy metal ions, and different concentrations of Cr3+ and Cd2+ were explored effects of single and compound stress on its biomass, chlorophyll a and related antioxidant enzyme activities. [Results] With the continuous increase of Cr3+ and Cd2+ concentrations, the concentration of algae cells increased first and then decreased; the content of chlorophyll a first decreased, then increased, and then decreased, with a maximum of 1 mg/L single and combined stress value, and the toxic effect is Cr3+
Xiao Liu , Zheng Zhang , Lifang Wang , Yongxiang Yu , Yingeng Wang , Meijie Liao , Guosi Xie , Jing Xing , Hao Zhang , Kai Wang , Yue Xu
2021, 61(7):2101-2111. DOI: 10.13343/j.cnki.wsxb.20200606
Abstract:Photobacterium damselae subsp. damselae (PDD) is an important pathogen distributed widely in global marine environment, which could infect multiple marine organisms, and reported in various mariculture regions of China in recent years. [Objective] This study aimed to systematically compare the phenotypic and genetic diversity of PDD isolated from Hainan province and Bohai Sea region base on physiological and metabolic phenotype, virulence gene distribute and molecular genetic analysis.[Methods] The physiological and metabolic phenotypes of sucrose fermentation, moveability, hemolysis, and phospholipase activity were assayed. The profiles of pPHDD1 replication origin, dly, hlyApl, hlyAch and plpV were investigated by PCR detection. Genetic diversity of PDD was analyzed based on the toxR sequences. [Results] Four PDD strains were positive for sucrose fermentation while other twelve strains were negative. There are significant differences among the motility of PDD, in which strain Pdd1608, Pdd2009, and Pdd1704 showed strong motility. Pdd1608 isolated from Bohai Sea region exhibited strong hemolysis and phospholipase activities, whlie strain Pdd1612 and Pdd0912 isolated from Hainan Province showed weak hemolysis and none phospholipase activities, and 13 strains showed weak hemolysis and phospholipase activities. The virulence gene profile of Pdd1608 was pPHDD1 replication origin-dly-hlyApl-hlyAch-plpV, while other strains were hlyAch-plpV. Phylogenetic analysis suggested remarkable genetic diversity among different kinds of PDD. [Conclusion] PDD isolated from Hainan Province and Bohai Sea region were probably composed of a polyclonal bacterial population with complex phenotypic characterizations, similar virulence gene profiles, and high genetic diversity.
Changjun Jiang , Cuicui Guan , Xiaomin Hu , Lunguang Yao , Yunchao Kan , Reng Qiu
2021, 61(7):2112-2120. DOI: 10.13343/j.cnki.wsxb.20200649
Abstract:[Objective] To investigate the effects of baicalin, a monomer of traditional Chinese medicine on growth and biofilm formation of Aeromonas hydrophila. [Methods] In vitro, antibacterial activity was determined based on the diameter of inhibition zone measured by Oxford cup method, biofilm formation was detected using the crystal violet method, bacteria motility was detected by swimming experiment. The ultraviolet (UV) absorption of the culture supernatant were measured to determine membrane integrity. Transmission electron microscopy (TEM) were performed to observe bacterial morphology. In vivo, the baicalin's effect on the proliferation of A. hydrophila was determined in grass carps. [Results] Baicalin has obvious bacteriostatic effect on A. hydrophila in vitro. The drug inhibited biofilm formation and bacterial motility. Under the action of baicalin, the cell structure was destroyed and the membrane permeability was increased. In vivo experiments showed a dose-dependent scavenging activity of baicalin on A. hydrophila. [Conclusion] The results showed the inhibitory effects of baicalin on the proliferation of A. hydrophila in vitro and in vivo, suggesting the potential use of this drug to control of aquaculture diseases.
Xiang Chen , Sijie Zhao , Tingting Liang , Jiran Zhang , Hongge Chen , Sen Yang
2021, 61(7):2121-2135. DOI: 10.13343/j.cnki.wsxb.20200689
Abstract:[Objective] A strain producing multiple enzymes was isolated from the egg surface of Hermetia illucens L. Further, the optimal growth conditions, enzyme-producing characteristics, and the effects of the strain on the food waste decomposition efficiency of Hermetia illucens L. were explored.[Methods] Enzyme-producing strains were obtained from various selective media. The optimal growth conditions, enzyme-producing characteristics, and the effects of it on the food waste treatment decomposition efficiency of Hermetia illucens L. were determined by the single-factor experiment. [Results] In this study, a Hermetia illucens L. egg-surface commensal bacterium was named as Bacillus velezensis EEAM 10B by morphological observation, biophysiological and biochemical tests, and 16S rDNA sequence analysis. The bacteria number was 3.1×109 CFU/mL under the optimum growth conditions:40℃, 200 r/min, pH 7.0, 10 g/L yeast extract, 10 g/L glucose for 16 h. Approximately 95.8% single-terminal spores were formed after 24 h cultivation. Enzymes producing results are as follows:xylanase activity was the highest, followed by the protease, cellulase, pectinase, amylase, and phytase. Adding the Bacillus velezensis EEAM 10B spores to the food waste at a dosage of 1×106 CFU/g significantly (P<0.05) improved the food conversion efficiency of black soldier fly larvae in both sterilized and non-sterilized food waste groups, reaching 13.4% and 13.54%, respectively, whereas the mass reduction rates did not present differences (P>0.05). Furthermore, in the sterilized food waste group, the survival rate of larvae and the prepupae weight were significantly increased to 95% and 0.1437 g per one, while the pupation rate reached 92.57% in the non-sterilized food waste group. [Conclusion] B. velezensis EEAM 10B strain can produce a variety of enzymes, and it has potential application value in the treatment of food waste with the black soldier fly.
Jie Zhou , Taixiang Xie , Jiangfeng Liu , Linying Lan , Yanfang Xu , Zhiyi Liu , Ye Ai , Qinghua Zhang
2021, 61(7):2136-2153. DOI: 10.13343/j.cnki.wsxb.20200692
Abstract:[Objective] To explore the community structure and biological function of Cymbidium ensifolium root symbiosis fungi.[Methods] Using high-throughput sequencing and FunGulid database, fungal species diversity and function of wild C. ensifolium rhizosphere soil (Rs), rhizoplane (Rp), and endoplane (Ep) at 4 samples in Hunan (HN), Fujian (FJ), Guizhou (GZ) and Yunnan (YN) Province were identified and predicted. [Results] The root symbiotic fungi of C. ensifolium are distributed in 12 phyla, 44 classes, 103 orders, 241 families and 432 genera. The main dominant phyla are Basidiomycota (49.51%), Ascomycota (27.39%) and Mortierellomycota (20.22%). At the genus level, Mortierella (11.75%), Saitozyma (11.45%) and Papiliotrema (7.93%) are the dominant genera. The nutrient types of symbiosis fungi in different C. ensifolium samples are quite different, but the structure of fungal nutrient types of each sample had a high similarity between the Rs and Rp; and the saprophytes was the absolute dominant type (50.11%-85.98%) in the Ep. However, FJ sample were special because of saprophytic trophic type dominated in the three ecological niches (85.98%-94.76%). The Rs and Rp fungi around the GZ sample were mainly of Pathotroph-Saprotroph-Symbiotroph and Symbiotroph type. The Rs and Rp of YN sample point were dominated by Saprotroph, Pathotroph-Saprotroph-Symbiotroph and Symbiotroph fungi. The Rs and Rp fungi of HN sample were also mainly composed of Saprotroph and Pathotroph-Saprotroph-Symbiotroph type. [Conclusion] The C. ensifolium root symbiosis fungi exhibit high diversity, and the community structure of the symbiosis fungi between each sample and each ecological niche point has extremely significant difference. The potential beneficial fungi of C. ensifolium root symbiotic fungi include Mortierella, Russula, Saitozyma, Papiliotrema, Cladophialophora, etc. This study provides a theoretical basis for revealing the symbiosis of C. ensifolium roots and fungi, as well as for the development and utilization of C. ensifolium symbiosis fungi.
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