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To establish a rapid and accurate method for the determination of Clostridium butyricum in microbial feed additives, different counting media and identification methods were compared and the samples in market were determined. The results showed that Clostridium butyricum could grow in sulfite iron agar, TSC agar and TSN agar, while the colony counting result of ferric sulfite agar medium was the highest. Clostridium butyricum could be identified by microbiochemical identification tubes, 16S rRNA gene amplifying and sequencing, qPCR amplification and MALDI-TOF MS, while the qPCR amplification was the most rapid and accurate as well as widely applied method. Two samples from market were determind with results of 9.1×108, 1.2×109 CFU/g respectively. Typical colonies were identified by qPCR with positive results. The study indicates that Clostridium butyricum in microbial feed additives can be effectively determined by ferric sulfite agar plate counting along with biochemical and molecular biological identification. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to screen antagonistic bacterial strains of mango anthracnose, so as to lay a theoretical basis for biological control of mango anthracnose and provide strain resources.【Method】Colletotrichum asianum,the dominant species of mango anthrax, was used as the target, and 37 strains of Bacillus spp. obtained in previous studies were used for confrontation culture and in vitro inoculation test. The antagonistic strains with obvious control effect were selected and their antagonistic mechanism was analyzed.【Result】The results of confrontation test showed that the inhibitory rates of 10 antagonists against C. asianum were more than 78.00%,among which the inhibitory rates of M12-5,L18-7,L19-3,L17-3 and M11-6 reached 96.24%,94.94%,94.10%,91.25% and 90.00%,respectively. Eight strains of Bacillus spp. with obvious control effect were obtained by in vitro inoculation, among which strains L18-7 and L16-4 had the best control effect, with the average control efficiency of 83.00% and 79.16%,respectively. There was no significant difference between them(P＞0.05). Combined with morphological characteristics, 16S rDNA sequence and phylogenetic tree analysis based on rpoB gene sequence, strain L18-7 could be identified as B. velezensis. Strain L18-7 could produce extracellular protease and cellulase, and could produce active antagonists in five media including Luria-bertani(LB),beef peptone(NA) and potato glucose agar(PDA) etc. Strain L18-7 carried genes related to antibiotic production such as mycB,ituA,yndJ,fenB and bacA.【Conclusion】The antagonistic bacterium strain L18-7 of mango anthracnose was identified as B. velezensis. The strain grew well on LB medium at 28 ℃.It could produce antagonistic substances, extracellular protease and cellulase and carried related genes of antibiotics such as mycB,ituA,yndJ,fenB and bacA. It can be used as germplasm resources for biocontrol bacteria. [ABSTRACT FROM AUTHOR]

Allelochemical signaling substances released by host roots and rhizosphere microbes play an important role in the host-seeking, mate-searching, and danger escape of root-knot nematodes (RKNs). At present, in order to develop chemoattractants and repellents of plant and microbial sources, it is an international hotspot and frontier for nematologists to identify semiochemicals and related molecular targets in the pre-infection stage of RKNs. This review focused on the chemotaxis and allelochemicals of RKNs, including attractive and repellent compounds, and summarized the progress on Trojan horse mechanism and trapping formation of RKNs. Furthermore, the application of the chemotactic models, including the plate agar and its modified model, Pluronic gel model, and the sand/soil model, on the nematodes chemotaxis test were summarized. Finally, the significance and challenge of the research on RKNs chemotaxis were discussed, and research directions on RKNs chemotaxis in the future were prospected. [ABSTRACT FROM AUTHOR]

The experiment was to explore Chinese medicine effective component from the rest of use value of waste liquid. Using chemical analysis method and AGAR plate punching method to assess the nutritional value and antibacterial effect, the determination of benefit, resistance to cold qingrejiedu, promote digestion and promoting blood circulation to remove blood stasis four categories a total of 21 kinds of commonly used traditional Chinese medical conventional nutrients content and pH value changes, to evaluate the antibacterial effect of Chinese patent medicine dregs on Escherichia coli, Staphylococcus aureus and Salmonella typhimurium. The results showed that the dry matter content of Tongmai granule (sucrose added) was the highest (99.10%), and that of Pharyngitis tablet was the lowest (71.86%). The crude protein (14.83%) and crude fat (9.52%) of Shenantler Bushen tablet were the highest, the crude protein (5.13%) of Ganmaoling capsule was the lowest, and the crude fat (0.88%) of Xiaomi Shuan was the lowest. Wujiashen Guiqi essence crude fiber content was the highest (61.68%), Liqi Shuxin tablet crude fiber content was the lowest (18.23%). The content of neutral detergent fiber (83.12%) and acid detergent fiber (69.98%) in compound Dantong tablet was the highest, the content of neutral detergent fiber in Liqi Shuxin tablet was the lowest (47.58%), and the content of acid detergent fiber in Care-guan preparation was the lowest (27.61%). The ash content of Qinglin granule was the highest (35.90%), and Baobao Le was the lowest (3.55%). Ginseng antler Bushen tablet, Qingliang Buccal tablet, pharyngitis tablet, Tongqiaobiyan tablet, Lianhua Qingwen capsule, Tongmai granule (without sucrose) and Danning tablet have certain antibacterial effects on Escherichia coli, Staphylococcus aureus and Salmonella typhimurium, and the antibacterial effect of different Chinese medicinal dregs are different. The experiment indicates that 21 kinds of Chinese medicine dregs all have certain nutritional value and bacteriostatic effect, which can be used as substitutes for bulk feed materials. [ABSTRACT FROM AUTHOR]

[Objective] Clarifying the composition of physiological races and virulence of Magnaporthe oryzae in rice blast nursery in Taojiang of Hunan province will provide a reference basis for utilization and development of rice varieties for resistance to rice blast disease in Hunan Province. [Method] The spore-generating ability of 64 rice blast isolates from Taojiang nursery was determined by inducing spore production on oat tomato agar medium ( OTA), and the physiological races of 53 strains were identified and their virulence was further analyzed by using in vitro leaf inoculation technology. [Result] Among 64 isolates collected from Taojiang nursery in 2018, 53 isolates could produce > 1 x 105 spores/mL after induced on OTA meidum, which met the requirement of in vitro leaf inoculation for spore concentration. Based on the reactions to seven Chinese differential varieties of rice, these isolates were divided into 4 groups and 12 physiological races, in which the dominant population was ZB with the frequency of 79. 2 %, and the dominant physiological race was ZB15 with the frequency of 39. 6%. Furthermore, ZB1 had strong pathogenicity and the second highest frequency, and ZA1 possessing the strongest pathogenicity was also isolated from Taojiang nursery. [Conclusion] The population of rice blast fungus from Taojiang nursery is very strong in virulence to Chinese differential varieties of rice, in which the dominant physiological race is ZB15. [ABSTRACT FROM AUTHOR]

The semi-lignified branches of last-growing Vlmus pumila were used as explants, 75% alcohol and 0.1% HgCl2 were used for disinfection. After initiation culture, the multiple shoots were first induced in the enrichment inedi-urn, and then cut into individual plants for rooting induction, and finally a lissue culture and rapid propagation system was established. The results showed that the optimal disinfection treatment combination of explanls was 75% alcohol treatment for 50 s + 0.1% HgCl2 treatment for 8 min, the contamination rate of explants was 17.3% and the survival rate was 78%. The sterilized explants were inoculated into the initiation medium and cultured for 25 d, and ihe most suitable medium for start-up of the explants was found to he MS + 1.0 mg L-1 6-BA + 0.1 mg L-1 IB A + 30 g L-1 sucrose + 6.5 g L-1 AGAR, with initiation rate up lo 87.5%. After the initial culture, axillary buds of the explanls were cut off and inoculated into the enrichment medium for multiple shoots induction. I'inally, the optimal enrichment medium was selected as MS + 0.5 mg · L-1 6-BA + 0.1 mg · L-1 KT + 0.1 mg · I/1 IBA + 30 g · L'1 sucrose + 6.5 g · L'1 AGAR, and the subculture cycle was 25 d with the increment coefficient as high as 6.2. The best rooting medium was 1/2 MS + 0.1 mg · L -i IBA + 0.1 mg · L-1 IAA+ 30 g · L-1 sucrose + 6.5 g · L-1 AGAR, and rooting was induced for 30 d with a rooting rate of 97%. After seedling adaptation, the tissue culture seedlings of U. pumila were transplanted to mixed matrix with perlite : vermieulite : peal (volume ratio 1:1:1), and the survival rate reached above 90%. Higher increment coefficient, rooting rale and transplant survival rate can reduce production cost and realize factory seedling breeding. [ABSTRACT FROM AUTHOR]

[Objective] Ormasia hosiei is a Chinese endemic endangered species with a high quality timber and excellent landscaping species. Phe optimal propagation conditions for tissue culture of Ormosia hosiei is screened to provide the theoretical basis and technological support for increasing propagation rate and perfecting the tissue culture system of Ormosia hosiei. [Method] The tender stem segments of Ormasia hosiei were used as the explants to study the effects of sterilization method;basic media;different sucrose and agar concentration and pll on initial culture of Ormosia hosiei stem segments. [Result] The contamination and survival rate ol Ormosia hosiei stem segments sterilized with 0.1 % KMnO4 for lOinin + 75 % alcohol for 30s + 0.1 % HgCl2 for 8min is 6.98 % and 100 % respectively. Hie optimal basic medium for initial culture o [Ormosia hosiei stem segments was 1/2MS + 30 g/L sucrose + 8 g/L agar + pH6.0 and the induction rate of cluster buds could be up to 85. 19 %. [Conclusion]The sterilization method,basic medium, sucrose and agar concentration and pH value are the important factors to influence initial culture of Ormosia hosiei stem segments. [ABSTRACT FROM AUTHOR]

Changes in the molecular mobility of agar were measured by pulsed-field-grdient stimulated echo (PFG-STE) 1H NMR after quenching，in order to elucidate the effect of different quenching temperature on gelation in agar solutions. Both the echo signal intensity of agar Iagar (0) and the diffusion coefficient of agar Dagar showed a steep decrease during the initial cooling stage (in the first ca. 30 minutes) and Iagar(0) decreased further with time going by，while Dagar increased a little after quenching occurred at around Ts-g and decreased a little when quenching temperature was below Ts-g. These results suggested that the gelation occurred in two stages: firstly the polysaccharide chains in agar aggregated into bundles to form a network when quenching happened. And then more and more agar chains were involved into the network. Changes became more rapidly and more obviously while the quenching temperatures was below Ts-g. [ABSTRACT FROM AUTHOR]

Objective To investigate the suitable observation concentration in the count of Candida albicans plate dilu-tion method by comparatively observing the growth situation in different concentrations of Candida albicans in LB nutrient agar culture plate. Methods The Candida albicans stock solution was diluted to about 1.5 ×109cfu/m L with No. A. Then 7 sterile tubes with 20 m L were taken, each tube was added with 9 m L sterile normal saline with No. B-H. One m L of bacterial solution was absorbed from the tube A to the tube B, after mixing, 1 m L of bacterial solution was absorbed again to the tube C, so did successive multiple proportion dilution to the tube H. 100 μL of different concentrations of Candida albicans suspension was absorbed by pipette to the one-off agar plate with corresponding number, which was evenly coated with the inoculating loop and cultured at 37 ℃incubator. Results After 48 h culture, Candida albicans with the order of magnitude 104 had smaller thallus with smaller volume than the order of magnitude 102, 103, while 105 was even more denser and smaller volume than 104, which was needle-shaped, its actual morphology was not easier to be observed by naked eye. When the orders of magnitude of Candida albicans was 102, 103, the fungal counting was 20-300 and could be counted, whereas the concentration orders of magnitude reached more than 104, which could not be counted. After 24, 48, 72 h culture, the agar culture plate was taken out for observing. The colony could be visually observed after 24 h culture, but the actual form was not obvious. After culturing for 48 h, the volume was large than that after culturing for 24 h culture, rough morphology could be seen, milky white round or oval, smooth surface and moist, shiny, diameter of1.0-2.0 mm. The volume after 72 h culture was slightly larger than that after 48 h culture, but the bacterial color was yellow. Conclusion The bacterial solution concentration of 1.5×102cfu/m L can be used as the suitable counting concentration of plate dilution method, culturing for 48 h is the best time to observe the colony morphology. [ABSTRACT FROM AUTHOR]

Slide culture preparations are necessary for accurately identifying dermatophytes. Because the standard slide culture technique is difficult for dermatologists to carry out, there is a need for an economical and easy-to-prepare system without special equipment. We placed a block of agar medium on a square cover glass (24 x 24mm) in the bottom of a case made of polypropylene (Free case, PK-201, HINODEWASHI CO., LTD. Japan). The agar block inoculated with fungi was overlaid with another cover glass on top of it. A plastic petri dish containing 4 cases as described above was sealed with adhesive plastic tape and incubated at 27°C. [ABSTRACT FROM AUTHOR]