从霍山石斛中分离内生菌,旨在获得具有广谱抗菌活性和促生作用的内生细菌。以石斛黑斑病菌为指示菌,用对峙培养法筛选具有抗菌活性的内生菌;对筛选到的具有拮抗活性的菌株进行抗菌谱和促生长潜力的测定。结果显示,从霍山石斛中分离获得2...从霍山石斛中分离内生菌,旨在获得具有广谱抗菌活性和促生作用的内生细菌。以石斛黑斑病菌为指示菌,用对峙培养法筛选具有抗菌活性的内生菌;对筛选到的具有拮抗活性的菌株进行抗菌谱和促生长潜力的测定。结果显示,从霍山石斛中分离获得22株内生细菌,其中菌株RA具有较强抑菌活性,根据16S r DNA序列分析结果鉴定RA为甲基营养芽孢杆菌Bacillus methylotrophicus。菌株RA可以产生IAA、嗜铁素、蛋白酶、表面活性剂和生物膜,RA对8种植物病原菌也具有较好的抑制作用,具有广谱抗菌活性;并且可以显著促进玉米幼苗的生长。RA菌株具有作为生防菌剂和生物肥料应用的良好潜力。展开更多
[Objective] This study was to investigate the effect of N＋ ion beam implantation on the survival rate and mutation rate of biocontrol strain Bacillus subtilis. [Method] The factors influencing B. subtilis ion beam im...[Objective] This study was to investigate the effect of N＋ ion beam implantation on the survival rate and mutation rate of biocontrol strain Bacillus subtilis. [Method] The factors influencing B. subtilis ion beam implantation, including culture time, dilution concentration, solvent, drying time of mycoderm were optimized. B. subtilis cells were implanted by using ion beam at dose of 2.0×10^14～4.0×10^14 ions/cm2 and the energy of 30 kev. Then the methods of culturing colonies confronting each other on plate and Oxford cup diffusion were used to screening strains. [Result] The optimal parameters were found as follows： culture in liquid for 20-24 h, dilution with sterile water to 106 cells/ml and drying time of 60 min for sample preparation; the optimal N＋ ion beam implantation dose of 2.0×10^14～4.0×10^14 ions/cm2 at the energy of 30 kev, the survival rate of 8.43%-26.71% and the mutation rate of 3.50%-5.43%. [Conclusion] This study provided reference for ion beam implantation mutation of B. subtilis.展开更多
[Objective] To study the effect of 60Co γ-rays irradiation on Botrytis cinerea biocontrol strains—Bacillus subtilis NCD-2. [Method] NCD-2 cells were irradiated at different doses of γ-rays from 100 to 2 000 Gy. The...[Objective] To study the effect of 60Co γ-rays irradiation on Botrytis cinerea biocontrol strains—Bacillus subtilis NCD-2. [Method] NCD-2 cells were irradiated at different doses of γ-rays from 100 to 2 000 Gy. The strains were screened by plate confrontation method and Oxford cup diffusion. [Result] The curves of the relationship of irradiation dose and mutation and lethal rate were obtained. The results showed that lethal rate increased with the increasing of irradiation dose. The lethal rate of 1 000 Gy irradiation dose reached 99.50%. The mutation rate increased below 500 Gy and decreased above 500 Gy. The highest mutation rate occurred when the irradiation dose was between 400 and 700 Gy, and the average mutation rate was above 15%. The optimal irradiation dose was 500 Gy, when the average mutation rate was 26.51% and lethal rate was 77.71%. [Conclusion] This study provided references for γ-rays irradiation mutation of Bacillus subtilis.展开更多
文摘从霍山石斛中分离内生菌,旨在获得具有广谱抗菌活性和促生作用的内生细菌。以石斛黑斑病菌为指示菌,用对峙培养法筛选具有抗菌活性的内生菌;对筛选到的具有拮抗活性的菌株进行抗菌谱和促生长潜力的测定。结果显示,从霍山石斛中分离获得22株内生细菌,其中菌株RA具有较强抑菌活性,根据16S r DNA序列分析结果鉴定RA为甲基营养芽孢杆菌Bacillus methylotrophicus。菌株RA可以产生IAA、嗜铁素、蛋白酶、表面活性剂和生物膜,RA对8种植物病原菌也具有较好的抑制作用,具有广谱抗菌活性;并且可以显著促进玉米幼苗的生长。RA菌株具有作为生防菌剂和生物肥料应用的良好潜力。
基金Supported by the"Bud Plan"Project of Beijing Academy of Science and Technology(No.022)~~
文摘[Objective] This study was to investigate the effect of N＋ ion beam implantation on the survival rate and mutation rate of biocontrol strain Bacillus subtilis. [Method] The factors influencing B. subtilis ion beam implantation, including culture time, dilution concentration, solvent, drying time of mycoderm were optimized. B. subtilis cells were implanted by using ion beam at dose of 2.0×10^14～4.0×10^14 ions/cm2 and the energy of 30 kev. Then the methods of culturing colonies confronting each other on plate and Oxford cup diffusion were used to screening strains. [Result] The optimal parameters were found as follows： culture in liquid for 20-24 h, dilution with sterile water to 106 cells/ml and drying time of 60 min for sample preparation; the optimal N＋ ion beam implantation dose of 2.0×10^14～4.0×10^14 ions/cm2 at the energy of 30 kev, the survival rate of 8.43%-26.71% and the mutation rate of 3.50%-5.43%. [Conclusion] This study provided reference for ion beam implantation mutation of B. subtilis.
基金Supported by Being Science and Technology Institute "Bud Plan" Project(No.022)~~
文摘[Objective] To study the effect of 60Co γ-rays irradiation on Botrytis cinerea biocontrol strains—Bacillus subtilis NCD-2. [Method] NCD-2 cells were irradiated at different doses of γ-rays from 100 to 2 000 Gy. The strains were screened by plate confrontation method and Oxford cup diffusion. [Result] The curves of the relationship of irradiation dose and mutation and lethal rate were obtained. The results showed that lethal rate increased with the increasing of irradiation dose. The lethal rate of 1 000 Gy irradiation dose reached 99.50%. The mutation rate increased below 500 Gy and decreased above 500 Gy. The highest mutation rate occurred when the irradiation dose was between 400 and 700 Gy, and the average mutation rate was above 15%. The optimal irradiation dose was 500 Gy, when the average mutation rate was 26.51% and lethal rate was 77.71%. [Conclusion] This study provided references for γ-rays irradiation mutation of Bacillus subtilis.
