Abstract:Soy isoflavones are a group of secondary metabolites produced during the growth of soya plants and have various physiological functions, including antioxidative activity, anticarcinogenic activity, prevention of bone loss, and decreasing the morbidity of cardiovascular disease. It is known that after being absorbed, soy isoflavones are metabolized by intestinal microflora to different metabolites with higher or wider bioactivities in comparison to soy isoflavones. Therefore, the beneficial effects of soy isoflavones depend mainly on how soy isoflavones are metabolized by intestinal microflora rather than the total amount of soy isoflavones absorbed by individuals. This paper reviews the microbial bioconversion of soy isoflavones from numerous aspects, including the function and component of soy isoflavones, the absorption, degradation and isolation of soy isoflavones, the bioactivity and enhanced biosynthesis of the microbial metabolites of soy isoflavones. The present research state and existing problems are addressed. The trends in future development are prospected. Our purpose is to accelerate the research and development of the microbial metabolites of soy isoflavones.

Abstract:High temperatures accelerate a rate at which deamination of a base forms a damaged base, and further replication of the deaminated base results in a mutation. Therefore, genomic stability of hyperthermophilic archaea is facing a challenge of high temperature environments in which they survive. Deamination of cytosine to form uracil is a common deaminated type, and the replication of uracil in DNA causes a mutation in GC→AT. Uracil DNA glycosylase (UDG) is a key enzyme in the repair of uracil in DNA. Based on their substrate specificity, UDGs are divided into six families and are widely distributed in bacteria, archaea, eukaryotes, and some viruses. Genomic sequences show that hyperthermophilic archaea encode at least one UDG. Currently, UDGs have been extensively studied for bacteria and eukaryotes, but research on the hyperthermophilic archaea UDGs is relatively rare and is still in its infancy. In this paper, research progress of hyperthermophilic archaea UDGs was reviewed, and their future research was proposed.

Abstract:[Objective] Breeding a new Spirulina strain with high-efficiency dehydration performance, and effectively reducing the energy consumption of dry powder production. [Methods] The spheroplasts of Spirulina platensis strain ZJU0115 that is widely used in large-scale cultivation, were prepared by tissue homogenate breaking and centrifugal sedimentation. They were treated by 0.6% EMS for 30 min and 2.4 kGy ⁶⁰Co gamma rays, and then screened by Zarrouk's medium containing 0.02% xanthan gum, cultured by the single filament separating, detected of water-holding rate in algae sludge and extracellular polysaccharide (EPS) content in filtrate. [Results] A mutant named ZJU0115(HD) was obtained. The yield and contents of protein and polysaccharide in ZJU0115(HD) were similar to that in ZJU0115, but the sludge water-holding rate and EPS content of ZJU0115(HD) decreased by 5.9% and 29.7% respectively. Ultrastructure analysis showed that the filament surface of ZJU0115(HD) was smoother and had fewer milky-white adhesives considered acidic polysaccharides than that of ZJU0115. And the polyphosphate granules in ZJU0115(HD) cells were significantly smaller and more dispersed. Moreover, RAPD (randomly amplified polymorphic DNA) analysis indicated that the amplifcation bands of primers S₉₀ revealed significant polymorphisms between ZJU0115(HD) and ZJU0115. [Conclusion] ZJU0115(HD) has good production traits and stable high-efficiency dehydration performance in industrial cultivation. In particular, nearly 50% of the energy consumption of its sludge drying could be saved. The new strain will help promote the current Spirulina industry to a new stage of high efficiency, energy saving, green and environmental protection.

Abstract:[Objective] The rhizosphere environment of terrestrial plants is closely related to the microbe in the soil. Accumulating evidences indicate that dynamics of rhizosphere microbial community directly affect plant health and nutrients utilization. Although rhizosphere microbes are useful for increasing crop productivity, their development has been limited due to a lack of understanding of the dynamics of microbiome. The dynamic changes of rhizosphere microbiome in the whole growth period of potato were studied, and the correlation between rhizosphere biomarkers and potato developmental stage was discussed here. This study will lay foundation for the development of special bio-probiotic fertilizer for different developmental stages of potatoes.[Methods] This study focused on the microbial dynamics of the whole life cycle of potato in field. The Illumina MiSeq high-throughput sequencing technology was used to sequence the 16S rRNA gene V3-V4 region and the fungal ITS region of potato rhizosphere microbe at different time points and to classify the OTUs, in order to analyze the diversity characteristics of microbial communities between samples, and we also established a model through machine learning to correlate rhizosphere microbes with potato development stages in the field. [Results] The rhizosphere microbiome changed significantly with developmental stages. The microbial community structure in the vegetative growth stage changed significantly and it gradually stabilized at beginning of the reproductive stage, and the rhizosphere microbiome varied a lot in the late stage of tuber maturity. In addition, 22 bacterial biomarkers and 16 fungal biomarkers associated with potato development stages were identified based on the model, which are the biomarker Clostridium in seedling stage and Actinobacteria in tuber matured stage. [Conclusion] The growth and development period of potato is the main factor affecting the composition of rhizosphere microbial community. The addition of probiotic fertilizer has a certain effect on maintaining and stabilizing the rhizosphere bacterial community in the late development stage.

Abstract:[Objective] Enterotoxigenic Escherichia coli (ETEC) is an important pathogen causing diarrhea of piglets. In this study, the prevalence and biological characteristics of ETEC in large-scale pig farms in northern Jiangsu was investigated, and protective and inactivated vaccines of predominant serotype were developed to provide guidance and suggestions for the prevention and control of ETEC in northern Jiangsu. [Methods] Fresh fecal samples, anal swabs and small intestinal tissue samples of piglets aged 3-30 days were collected from large-scale pig farms in northern Jiangsu province, ETEC was isolated, and serotypes, antibiotic resistance, pathogenicity on mice of these isolates were determined. Finally, the inactivated vaccine of predominant serotype was developed and the immune protection effect of mice was evaluated. [Results] We collected 562 samples from 21 large-scale pig farms. We identified 141 ETEC strains containing ST or LT virulence genes by PCR. O serotypes of 85 isolates were determined by serum agglutination tests. O8, O101 and O128 were dominant serotypes, accounting for 61.2% of the confirmed strains, besides, O9, O3, O20, O148, O149 and the like were identified. The drug resistance of 141 ETEC isolates to 14 common antibiotics was analyzed. The isolates were highly resistant to neomycin, erythromycin, tetracycline, gentamicin, doxycycline, amoxicillin, and trimethoprim/sulfamethoxazole, with resistance rate higher than 80%. Strains were most sensitive to enrofloxacin, with the rate of 50.4% (71/141). 66% (93/141) and 51.8% (73/141) strains were intermediate to polymyxin B and cefotaxime. Multiple drug resistance is serious. 19% (27/141) of strains were resistant to 10 drugs. The virulence of the dominant serotype strains was obtained by mice challenge test. LD₅₀ of one strong strain YC-6 of O8 serotype was measured as 1.4×10⁷ CFU, while the MLD₅₀ was 3×10⁷ CFU. The monovalent inactivated vaccines prepared by O8 virulent strain YC-6 and O101 virulent strain LYG-3 both have a protection rate of 100% for mice. The bivalent inactivated vaccine of YC-6 and LYG-3 were developed as well, the protection rate of which in mice was more than 83%. [Conclusion] Based on the epidemiological investigation of ETEC in northern Jiangsu, dominant serotypes and drug resistance were tested, and bivalent inactivated vaccine with superior immune protection effect against isolated strains were developed, which will provide reference for monitoring and prevention in pig industry.

Abstract:[Objective] To isolate antagonistic bacteria against Sclerotinia sclerotiorum diseases in sunflower. [Methods] Cellulose-degrading bacteria were isolated by CMC and wheat straw cellulose as sole carbon and energy source in mineral culture medium, then the ability of cellulose-degrading bacteria to suppress Sclerotinia sclerotiorum mycelium development was recorded under various conditions. The antagonistic spectrum of the isolate YC16 against pathogenic fungi was tested on PDYA petri-dishes, the suppressive ability of YC16 against Sclerotinia sclerotiorum was also observed using fresh detached leaves of sunflower and peat pot experiment. The effect of YC16 inoculation on plant growth promotion and Sclerotinia rot diseases prevention of sunflower was studied in pot and field experiment. [Results] YC16 was isolated and identified as Bacillus amyloliquefaciens. YC16 could suppress eight pathogenic fungi, including Sclerotium rolfsii, Fusarium solani, Fusarium oxysporum, Pyricularia oryzae, Phytophthora capsici, Fusarium sp., Fusarium oxysporum f. sp. cucumerinum Owen and Sclerotinia sclerotiorum. YC16 could inhibit S. sclerotiorum from infecting sunflower leaves by 80.42% and reduce the density of S. sclerotiorum mycelia by more than 50% on the surface of the Peat media compared with the control under pot condition. YC16 inoculation increased obviously the fresh biomass weight of sunflower by 54.9%. Under conventional chemical fertilizer application, YC16 inoculation increased sunflower yield by 24.4% to 30.2%, S. sclerotiorum diseases of sunflower was reduced by 39% to 100% through 3 year's field studies. [Conclusion] The isolate YC16 showed the potential for controlling sunflower Sclerotinia rot diseases and increasing sunflower yields as an efficient microbial resource for development of biocontrol agent.

Abstract:[Objective] To obtain and identify mutants related to indole regulation will provide functional genes responding for bacterial survival adaptability and in-planta colonization/association, which will be significant to the study of indole regulation pathway. [Methods] A mutant library of YJ76 was constructed by mTn5 transposon mutagenesis method, from which the mutant genes could be identified by using the high-efficiency TAIL PCR (hiTAIL-PCR) technique. [Results] A mutant strain named M04 with significantly increased indole production was selected from the mutant library of YJ76, and the mutation site was identified as a new gene (195 bp), which we named as ipc (indole production control) gene. This mutation enhanced the bacterial resistance to heavy metals, tetracycline and acids, and also enhanced the colonizing/plant growth-promoting ability of the endophyte on rice.[Conclusion] By carrying ipc mutation, the mutant strain increased indole production, resulting in the improved survival adaptability and higher association ability on the host rice.

Abstract:[Objective] Pedidcularis kansuensis forms parasitic relationship with Epichloë-infected host grasses through root haustoria connections. However, only few studies have paid attention to the effects of Epichloë endophyte on host grass photosynthetic characteristics while the host grasses were parasitized by root hemiparasitic plants. [Methods] Thus, in this study, we evaluated effects of endophyte infection on net photosynthesis rate (P_n), transpiration rate (T_r), stomatal conductance (G_s), concentration of CO₂ intercellular (C_i) and water use efficiency (WUE) of two host grasses (Stipa purpurea and Elymus tangutorum) in the presence (or absence) of P. kansuensis.[Results] Irrespective of endophyte status, P_n, T_r and G_s of host plants decreased in the presence of P. kansuensis; however, C_i and WUE of host plants increased in the presence of P. kansuensis. P_n, T_r and G_s of endophyte-infected (E+) S. purpurea were higher than endophyte-free (E-) counterpart, while C_i and WUE of E+ S. purpurea were lower than E- ones. By contrast, P_n, T_r and G_s of E+ E. tangutorum was lower than E- counterpart, while C_i and WUE of E+ E. tangutorum higher than E- ones. [Conclusion] Consequently, these results suggest that interactions between endophyte and host grasses are context-dependent, and the relationships between host grass and Epichloë endophyte range from mutualism to parasitism when grasses become common hosts to root hemiparasitic plant and Epichloë endophyte.

Abstract:[Objective] Pseudomonas putida SJTE-1 can degrade17β-estradiol (E2) efficiently, but its degradation mechanism is still unclear. Here we characterized a 17β-hydroxysteroid dehydrogenase 2 (17β-HSD2) and one AraC regulator responsible for oxidization and regulation of E2 biodegradation. [Methods] We detected the transcription of 17β-hsd2 and araC by reverse transcription and quantitative PCR. We overexpressed 17β-HSD2 and AraC in Escherichia coli BL21(DE3) strain and purified them with metal-ion affinity chromatography. We characterized the enzymatic properties of 17β-HSD2 in vitro and detected the product with High Performance Liquid Chromatography. We determined the binding capability and binding sites of AraC by electrophoretic mobility shift assay and DNase I footprinting assay. [Results] Results showed the transcription of 17β-HSD2 and AraC were induced by E2. Multiple sequences alignment showed 17β-HSD2 contained the conserved structure and residues of short-chain dehydrogenase/reductase and β-hydroxysteroid dehydrogenase. 17β-HSD2 oxidized E2 at C₁₇ site using NAD⁺ as cofactor, with 0.0802 mmol/L K_m value and 56.26±0.02 μmol/(min·mg) V_max value; over 97.4% of E2 was transformed into estrone in five minutes. AraC protein could directly bind to the specific sites in the promoter region of 17β-hsd2, which could be released by E2 or estrone. Overexpression of AraC repressed the transcription of 17β-hsd2 significantly. [Conclusion] 17β-HSD2 catalyzed the transformation of 17β-estraiol efficiently and was regulated by AraC in P. putida SJTE-1. This work promoted the enzymatic mechanism and the regulatory network studies about bacterial estrogen biodegradation.

Abstract:[Objective] Hydrolysis of ginkgo flavonoid glycosides by microbial β-glucosidase is less known. Therefore, we screened a microbial β-glucosidase with high enzymatic activity to hydrolyze ginkgo flavonoids and analyze its substrate-specificity. [Methods] β-Glucosidases with high enzymatic activity for the hydrolysis of ginkgo flavone glycoside were screened from traditional fermented soybean meal in Guizhou using Ginkgo biloba extract as the sole carbon source. The strain producing glucosidase was then identified, and the selectivity of the enzyme to different substrates was compared. The Michaelis constant K_m and maximum velocity V_max of the enzymatic reaction to hydrolyze ginkgo flavonoids were determined. Finally, the substrate-specific mechanism of the enzyme was analyzed via molecular docking studies. [Results] Among the strains observed, strain GUXN01 showed the highest β-glucosidase activity and was subsequently identified as Bacillus subtilis. β-glucosidase produced by GUXN01 had broad substrate specificity to sugars and glycosides with the β configuration. The glucosidase showed especially good affinity to ginkgo flavonoid glycosides. Molecular docking studies indicated that B. subtilis β-glucosidase had different affinities and selectivities toward ginkgo flavonoid glycosides and other glycosides due to differences in the interactions between the enzyme and substrate structures. [Conclusion] These findings may serve as a good foundation for the production of the corresponding aglycones via the hydrolysis of ginkgo flavonoid glycosides through the β-glucosidase produced by GUXN01.

Abstract:[Objective] It is important to study the nutrition relationship between tobacco bacterial wilt pathogen (Ralstonia solanacearum, Rs) and its antagonistic bacterial isolate LX4. The difference in their use of secreted chemicals from tobacco root plays a crucial role for increasing the colonization of antagonist and efficiently bio-controlling tobacco bacterial wilt. [Methods] Pathogen Rs and the antagonistic strain LX4 from tobacco field soil were isolated and identified. We examined the use of characteristic carbon and nitrogen sources in tobacco root exudates by Rs and LX4. Main chemicals in root exudates were identified with a gas chromatography-mass spectrometer (GC-MS). We compared and analyzed the capacity and intensity of utilizing the major nutrients by Rs and strain LX4 by co-culturing the two microorganisms. [Results] The isolated pathogen was identified as R. solanacearum and isolate LX4 was identified as Bacillus subtilis via phylogenetic tree analysis based on their 16S rDNA sequences. In the exudates of tobacco roots, the substances with contents of > 0.01 μg/mL were ordered descendingly as pectin > glucose > xylose > arabinose > galactose > ribose > sucrose > benzoic acid > fructose=D-mannitol > cetylic acid > fumaric acid. The content of pectin was the highest and significantly higher than all the other substances. Strain LX4 could use arabinose, xylose and ribose significantly better than R. solanacearum. The usage capacity of the former was 1.22, 1.95 and 2.17 times of those of the latter, respectively. Besides, the fructose usage by LX4 was higher than that by R. solanacearum in the first 12 h. After 24 h of co-culturing them on different substrates of carbon sources, the suppression rates of strain LX4 to R. solanacearum marked by green fluorescent protein were 18.34% (arabinose), 53.23% (xylose), 63.53% (ribose) and 52.09% (fructose). [Conclusion] In conclusion, the capacity of root exudates from LX4 was lower than that from Rs, which suggested the antagonist had disadvantage in its nutrition competition with the pathogen. However, the antagonist took the advantage of certain carbon substances secreted from tobacco roots to produce antagonistic substances, which were suppressive or toxic to the pathogen. There were both exploitation and interference competitions between the antagonist and pathogen. These results provide some theoretical evidences for the bio-control of tobacco bacterial wilt caused by R. solanacearum in the near future.

Abstract:[Objective] The determinant virulence factor Listeriolysin O (LLO) of Listeria monocytogenes, a foodborne pathogen, contains a unique N-terminal amino acid sequence that is absent in other cytolysins and was previously referred as the PEST-like sequence (containing three putative phosphorylation sites, S44, S48, and T51). We here, therefore, aimed to explore the biological roles of the PEST-like sequence in LLO-induced ERK1/2 kinases phosphorylation in human epithelial cells (Caco-2). [Methods] The plasmid for expressing the recombinant LLO was constructed and transformed into E. coli Rosetta, and the his-tagged soluble protein was purified using the nickel-chelated affinity column chromatography. The LLO variants (LLO_ΔPEST, LLO_S44A, LLO_S48A, and LLO_T51A) were then obtained by using the site-directed mutagenesis strategy and expressed as above for LLO. The hemolytic activity for these recombinant proteins was assessed by lysis the erythrocytes, and moreover, effects of LLO or its variants on ERK1/2 kinases phosphorylation in Caco-2 cells was detected by using the Western blotting method. [Results] The results in the present study showed that the recombinant LLO, as well as the four LLO variants were able to lysis the erythrocytes at pH 5.5 and pH 7.4, suggesting that the PEST-like sequence was not required for the pore-forming activity of LLO. Besides, treatment of the LLO or its variants at the cytolytic concentration of 5 nmol/L could significantly induce ERK1/2 kinases phosphorylation in Caco-2 cells. [Conclusion] Our data collectively showed that the PEST-like sequence was not necessary for the LLO-mediated perforation ability on host membranes and not required for the LLO-triggered ERK1/2 signaling, which laid the foundation for further exploration of the potential roles of this motif during L. monocytogenes infection.

Abstract:[Objective] We studied the diversity and crop-growth promotion of marine nitrogen-fixing bacteria and screened for excellent plant rhizosphere-promoting strains. [Methods] We identified the representative strains by morphological, physiological and biochemical characteristics, and 16S rRNA gene sequence alignment analysis. We used strains with excellent properties as the combined bacterial liquids in the pot-planting test. [Results] We isolated a total of 18 nitrogen-fixing bacteria from the offshore of Donghai Island in the South China Sea, which were classified into 9 species of 6 genera, belonging to 4 strains of the genus Acinetabacter, 1 strain of the genus Pseudoalteromonas, 8 strains of the genus Bacillus, 1 strain of the genus Psyctrobacter, 1 strain of the genus Oceanimonas and 3 strains of the genus Alteromonas. The seedlings of Chinese flowering cabbage were irrigated by combined microbial agents. Among them, the strains of the genera Bacillus and Acinetobacter had a key promoting effect in the growth process of Chinese flowering cabbage, and showed the best growth promoting effect on Chinese flowering cabbage. [Conclusion] This study provides an important basis for the targeted utilization of marine microbial resources and the pollution-free production of vegetables.

Abstract:[Objective] A broad-spectrum antagonistic strain with high antibacterial ability was screened from the garbage heap soil and its antibacterial properties were studied for pollution control of township garbage accumulation sites. [Methods] Antagonistic fungi were isolated from the soil of garbage accumulation sites in townships by plate dilution method and cylinder-plate method, and the antagonistic strains were identified by morphological observation, physiological and biochemical characteristics and molecular biological identification. Suitable organic reagents were selected to extract mycelia and fermentation broth of antagonistic fungi, by measuring the polarity of antibacterial active substances. The TLC-Bioautography method was used to analyze the bacteriostatic active components in the fermentation broth and mycelia. Determination of antibacterial spectrum of ethyl acetate extract of mycelium used 23 indicator bacteria. The high-temperature tolerance, acid-base tolerance, ultraviolet stability, natural light stability of the crude extract and the minimum inhibitory concentration against Escherichia coli and Candida albicans were determined. [Results] A passaging stable broad-spectrum antagonistic fungus DAZ-2 was isolated and identified as Aspergillus fumigatus by morphological observation, physiological and biochemical characteristics, and ITS sequence analysis. Selecting ethyl acetate reagent to extract methanol extract and fermentation broth of Aspergillus fumigatus DAZ-2 fermentation mycelium. The TLC-Bioautography method showed that the antibacterial active substances in the two were not the same component, and the multi-component substances cooperated to produce a bacteriostatic effect. The crude ethyl acetate extract of fermenting mycelium (200 μg/mL) has antibacterial effect on 11 indicator bacteria, and the MIC of Escherichia coli and Candida albicans is 7.50 and 15 μg/mL, and the antibacterial ability was stable, tolerated to temperature, light, ultraviolet, acid, and alkali. [Conclusion] A wide-spectrum antagonistic strain, Aspergillus fumigatus DAZ-2 with high antibacterial activity and stable passage was isolated, which is expected to provide a scientific basis for the development of microbial drugs and the pollution control of garbage accumulation sites in villages.

Abstract:[Objective] To mine new antimicrobial agents from Bacillus coagulans LL1103 isolated from large yellow croaker.[Methods] The ethyl acetate and n-butanol extracts of B. coagulans LL1103 fermentation broth were separated and purified by chromatographic techniques, and their structures were identified based on spectral analysis. Their antibacterial activities were detected by micro-broth dilution method. [Results] From the fermentation broth of B. coagulans LL1103, 9 cyclic dipeptides (1-9) were obtained as (1) cyclo-(4-Hydroxyl-Pro-Leu), (2) cyclo-(Ile-Ala), (3) cyclo-(Pro-Val), (4) cyclo-(Pro-Phe), (5) cyclo-(Pro-Leu), (6) cyclo-(Gly-Ala), (7) cyclo-(Pro-Gly), (8) cyclo-(Pro-Ala) and (9) cyclo-(Tyr-Gly). Cyclic dipeptides 3, 7 and 9 showed strong antibacterial activities against Escherichia coli with minimal inhibitory concentration values of 8.0, 4.0 and 16.0 μg/mL, respectively. [Conclusion] Three compounds showed remarkably biological effect on the growth of E. coli.

Abstract:[Objective] A new jujube disease has emerged in Aksu and other areas in Xinjiang since 2016, seriously threatening the local and surrounding jujube industries during the last three years. This study aims to identify the causative pathogen(s) and to investigate the pathogen transmission route(s), therefore providing guides for the disease control strategies. [Methods] Small RNA sequencing was performed to identify potential pathogen(s), which revealed a new jujube virus. RNAseq and reverse transcription PCR (RT-PCR) were performed to obtain the whole genomic sequence of the identified virus. A viral protein was in-vitro expressed for antibody preparation. Western blotting with the viral specific antibody confirmed the specific existence of the viral protein in infected plants. Insects were collected in the disease-occurred areas and RT-PCR was performed to identify potential virus-transmission vector(s).[Results] This study identified a new virus, belonging to Emaravirus and named as Chinese date mosaic-associated virus (CDMaV) in this study, as a correlated causative regent for Xinjiang jujube disease. We obtained the whole genomic sequence of this viral strain. The CDMaV genome is segmented and consists of five segments of linear negative-sense and single-stranded RNA. The complete genome is 13.078 kb, with RNA1-RNA5 containing 7160 nt, 2224 nt, 1230 nt, 1493 nt, and 971 nt, respectively. The complementary strand of each genomic RNA encodes a single open reading frame, sequentially the five encoded proteins are RNA-dependent RNA polymerase, envelope glycoprotein, nucleocapsid protein, and two unknown functional proteins. The virus specific sequences could be amplified from Epitrimerus zizyphagus, indicated that CDMaV might be transmitted from infected jujube trees to the healthy plants via this insect vector. [Conclusion] This study identified CDMaV as the correlated causative agent for the newly emerged jujube disease in Xinjiang, sequenced the viral genome and identified E. zizyphagus as a potential insect vector for viral transmission. Identification of pathogen and its transmission route would efficiently guide the development of disease control strategies.

Abstract:[Objective] In this study, the host range of phage QL01 was changed by replacing the gene fragment of QL01 gp37. This lays the foundation for studying the host range mechanism of T4 phage and rapid screening of phages targeting specific pathogens. [Methods] Eight gene fragments on WG01 gp37 were substituted by QL01 using homologous recombination, and then the different chimeric phages were screened and their host range determined by using Salmonella as the host strain. Finally, the biological characteristics such as the optimal multiplicity of infection, one-step growth curve, and other biological characteristics of the chimeric phage QWG were analyzed, as well as the genetic stability. [Results] A total of five chimeric phages (QWA, QWC, QWF, QWG, QWFG) were obtained in this experiment. The results of the host range analysis test showed that chimeric phage could lyse 7, 8, 4, 10 and 9 strains of Salmonella, respectively, compared to phage QL01. That is to say, chimeric phages have all obtained a relatively broad host range of which the host bacteria of QWG widened the most. The results of biological characteristics test showed that the chimeric phage QWG has stable biological properties. We cultured the chimeric phage QWG continuously for 20 generations, sequenced the tail genes from the first and 20th generation chimeric phage and analyzed their hereditary stability. The sequencing results indicated that the gene fragment of the chimeric phage engineered part could stably inherit. [Conclusion] Genetic engineering can generate chimeric phage with broadened host range and hereditary stability, which provides a possibility for rapid screening of phage against specific pathogens.