[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomat...[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomato stems by UV mutagenesis for two consecutive times,then genetic stability as well as physiological and biochemical properties of mutant strains were studied.[Result] The antibacterial activity of all the three mutant strains F303,F304 and F305 was higher than that of B74 strain.After subculture of 10 successive generations,the antibacterial activity of all the three mutant strains for the pathogens of watermelon fusarium wilt decreased,but the antibacterial activity of F305 strain decreased the least,indicating its best genetic stability among the tested strains.The antibacterial circle diameter of F305 strain was 5 mm larger than that of wild strain B47 under the same condition.The mutant strain F305 was in logarithmic growth phase within 36 h and in stationary phase within 36-96 h,while its optimum growth temperature was 35 ℃.F305 strain could grow in sodium salt with the concentration of 1%-10%,but it grew best at the concentration of 1%.Physiological and biochemical responses of F305 strain were in accordance with those of wild strain B47.[Conclusion] This study lays the foundation for the factorial production of antagonistic substance by B47 strain and new methods of preventing from the pathogens watermelon fusarium wilt.展开更多
[Objective] The stability of antimicrobial active ingredients of Bacillus subtilis B26 was studied. [Method] The Fermentation broth of B. subtilis B26 was passed through porous membrane after centrifugation,70% (NH4...[Objective] The stability of antimicrobial active ingredients of Bacillus subtilis B26 was studied. [Method] The Fermentation broth of B. subtilis B26 was passed through porous membrane after centrifugation,70% (NH4)2SO2 was used to carry out precipitation,and the sterile crude extracts with resistance against Fusarium decemcellulare Brick were still obtained after dialysis. Plate coated perforated method was adopted to detect the treatment stability towards crude extracts on temperature,pH,ultraviolet radiation,organic solvents and protease. [Result] The inhibition diameter of crude extracts of B. subtilis B26 after treatment at 100 ℃ was 78.2% of the treatment at room temperature,but the crude extracts of B. subtilis B26 completely lost their activity after treatment at 121 ℃; the crude extracts of B. subtilis B26 all had antimicrobial activity in the pH value range of 3-10,and the antimicrobial activity was the largest when the pH value was 7.0; when the crude extract of B. subtilis B26 was irradiated by UV light (power 20 W) for 80 min from 40 cm distance away,the antimicrobial activity of which was 78.1% of the control; when it was treated with ether,chloroform,methanol and acetone for 30 min,the antimicrobial activities of crude extracts of B. subtilis B26 were 96.4%,85.7%,82.1% and 81.5% of the control,respectively; when it was treated with proteinase K,trypsin and pepsin,the inhibition diameters of crude extracts of B. subtilis B26 were 15.2,16.2 and 16.3 mm,the antimicrobial activities were 76.7%,81.8% and 83.3% of the control,respectively. [Conclusion] The crude extracts of B. subtilis B26 had higher antimicrobial stability.展开更多
The gut microbiota plays important roles in animal overall health and productiveness. Balancing host gut microbiota by probiotics has been documented. Our previous study showed that Saccharomyces boulardii(Sb) and Bac...The gut microbiota plays important roles in animal overall health and productiveness. Balancing host gut microbiota by probiotics has been documented. Our previous study showed that Saccharomyces boulardii(Sb) and Bacillus subtilis B10(Bs) significantly improve growth performance and modulate the intestinal histomorphology in broilers. To increase the knowledge regarding Sb and Bs, this study investigated the effects of these 2 probiotic strains on the gut microbiota in broilers. Three hundred 1-day-old Sanhuang broilers(Chinese cross breed) were randomly divided into 3 groups, each group with 5 replications(n = 20). The control group(CK) was fed a basal diet containing an antibiotic(virginiamycin, 20 mg/kg) and the other 2 groups received Sb and Bs(1 × 10~8cfu/kg of feed) in addition to the basal diet. After 72 d of treatment, pyrosequencing revealed that the bacterial communities varied along the section of intestinal tract in the control and Bs groups, but not in the Sb group. No difference in microbial diversity was observed among 3 groups. The major phyla observed along the GI tract of broilers(particularly in the duodenum and cecum) were Firmicutes, Bacteroidetes, Proteobacteria, and Verrucomicrobia, which were considered potentially growth performance-related. Bacteroidetes, Proteobacteria, and Verrucomicrobia were observed at a much higher abundance in the jejunums and ileums of the Sb group(P < 0.05). In addition, the jejunal microbial communities formed 3 different clusters at either the genus level or the category of metabolism among the groups, based on the principal component analyses. These data indicated that Sb and Bs can modulate the microbial ecosystem, and subsequently enhance the health status of broilers.展开更多
基金Supported by the Fund of Science and Technology in GuangXi Zhuang Autonomous Region(0009018)~~
文摘[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomato stems by UV mutagenesis for two consecutive times,then genetic stability as well as physiological and biochemical properties of mutant strains were studied.[Result] The antibacterial activity of all the three mutant strains F303,F304 and F305 was higher than that of B74 strain.After subculture of 10 successive generations,the antibacterial activity of all the three mutant strains for the pathogens of watermelon fusarium wilt decreased,but the antibacterial activity of F305 strain decreased the least,indicating its best genetic stability among the tested strains.The antibacterial circle diameter of F305 strain was 5 mm larger than that of wild strain B47 under the same condition.The mutant strain F305 was in logarithmic growth phase within 36 h and in stationary phase within 36-96 h,while its optimum growth temperature was 35 ℃.F305 strain could grow in sodium salt with the concentration of 1%-10%,but it grew best at the concentration of 1%.Physiological and biochemical responses of F305 strain were in accordance with those of wild strain B47.[Conclusion] This study lays the foundation for the factorial production of antagonistic substance by B47 strain and new methods of preventing from the pathogens watermelon fusarium wilt.
基金Supported by National Natural Science Foundation of China (31070555)Research Projects for Students Studied Abroad in Shanxi Province(2008-119)+1 种基金Shanxi Agricultural research (20100311001-7)High School Special Project in Shanxi Province~~
文摘[Objective] The stability of antimicrobial active ingredients of Bacillus subtilis B26 was studied. [Method] The Fermentation broth of B. subtilis B26 was passed through porous membrane after centrifugation,70% (NH4)2SO2 was used to carry out precipitation,and the sterile crude extracts with resistance against Fusarium decemcellulare Brick were still obtained after dialysis. Plate coated perforated method was adopted to detect the treatment stability towards crude extracts on temperature,pH,ultraviolet radiation,organic solvents and protease. [Result] The inhibition diameter of crude extracts of B. subtilis B26 after treatment at 100 ℃ was 78.2% of the treatment at room temperature,but the crude extracts of B. subtilis B26 completely lost their activity after treatment at 121 ℃; the crude extracts of B. subtilis B26 all had antimicrobial activity in the pH value range of 3-10,and the antimicrobial activity was the largest when the pH value was 7.0; when the crude extract of B. subtilis B26 was irradiated by UV light (power 20 W) for 80 min from 40 cm distance away,the antimicrobial activity of which was 78.1% of the control; when it was treated with ether,chloroform,methanol and acetone for 30 min,the antimicrobial activities of crude extracts of B. subtilis B26 were 96.4%,85.7%,82.1% and 81.5% of the control,respectively; when it was treated with proteinase K,trypsin and pepsin,the inhibition diameters of crude extracts of B. subtilis B26 were 15.2,16.2 and 16.3 mm,the antimicrobial activities were 76.7%,81.8% and 83.3% of the control,respectively. [Conclusion] The crude extracts of B. subtilis B26 had higher antimicrobial stability.
基金supported by the 12th Five-Year-Plan in National Science and Technology for Rural Development in China(2013BAD10B03)the National 863 Project in China(2013AA102803D)the Key Science and Technology Program of Zhejiang Province,China(No.2006C12086)
文摘The gut microbiota plays important roles in animal overall health and productiveness. Balancing host gut microbiota by probiotics has been documented. Our previous study showed that Saccharomyces boulardii(Sb) and Bacillus subtilis B10(Bs) significantly improve growth performance and modulate the intestinal histomorphology in broilers. To increase the knowledge regarding Sb and Bs, this study investigated the effects of these 2 probiotic strains on the gut microbiota in broilers. Three hundred 1-day-old Sanhuang broilers(Chinese cross breed) were randomly divided into 3 groups, each group with 5 replications(n = 20). The control group(CK) was fed a basal diet containing an antibiotic(virginiamycin, 20 mg/kg) and the other 2 groups received Sb and Bs(1 × 10~8cfu/kg of feed) in addition to the basal diet. After 72 d of treatment, pyrosequencing revealed that the bacterial communities varied along the section of intestinal tract in the control and Bs groups, but not in the Sb group. No difference in microbial diversity was observed among 3 groups. The major phyla observed along the GI tract of broilers(particularly in the duodenum and cecum) were Firmicutes, Bacteroidetes, Proteobacteria, and Verrucomicrobia, which were considered potentially growth performance-related. Bacteroidetes, Proteobacteria, and Verrucomicrobia were observed at a much higher abundance in the jejunums and ileums of the Sb group(P < 0.05). In addition, the jejunal microbial communities formed 3 different clusters at either the genus level or the category of metabolism among the groups, based on the principal component analyses. These data indicated that Sb and Bs can modulate the microbial ecosystem, and subsequently enhance the health status of broilers.