To improve antagonistic metabolites production of Bacillus subtilis strain BS501a, physical parameters of fermentation and metal inorganic salts in medium, namely initial pH value, culture temperature, fermentation ti...To improve antagonistic metabolites production of Bacillus subtilis strain BS501a, physical parameters of fermentation and metal inorganic salts in medium, namely initial pH value, culture temperature, fermentation time, concentrations of CaC12, FeSO4, ZnSO4, MnSO4 and MgSO4, were optimized using one-factor-at-a-time and orthogonal tests. The results show that the optimal physical parameters of fermentation are an initial pH of 7.0, a culture temperature of 30 ~C, and a fermentation time of 48 h. The optimal concentrations of metal inorganic salts in basal medium are 10.2 mmol/L CaCl2, 0.4 mmol/L FeSO4, 3.5 mmol/L ZnSO4, 0.6 mmol/L MnSO4 and 2.0 mmol/L MgSO4. Among the metal inorganic salts, MgSO4 and MnSO4 play important roles in the improvement of the antagonistic metabolites production of B. subtilis strain BS501a; especially, MgSO4 contributes a highly significant effect. The average diameter of inhibition zone of the BS501a filtered fermentation supernatant （FFS） cultured in the optimal fermentation conditions against Magnaporthe grisea DWBJ329 reaches 71.4 mm, and there is 2.4-fold increase in antifungal activity as compared with 21.2 mm under the pre-optimized conditions.展开更多
菌株AF0907是从土壤中分离到的1株对小麦赤霉病菌具有显著拮抗作用的枯草芽孢杆菌,该菌株不仅对小麦赤霉病菌具有很好的拮抗活性,对其他多种植物病原菌都具有很好的拮抗效果。为了明确菌株AF0907对赤霉病菌的抑菌机理,本研究首先使用平...菌株AF0907是从土壤中分离到的1株对小麦赤霉病菌具有显著拮抗作用的枯草芽孢杆菌,该菌株不仅对小麦赤霉病菌具有很好的拮抗活性,对其他多种植物病原菌都具有很好的拮抗效果。为了明确菌株AF0907对赤霉病菌的抑菌机理,本研究首先使用平板对持法对拮抗物质进行定位,结果表明该菌分泌的拮抗物质主要位于细胞上清液中。采用不同饱和度的硫酸铵沉淀细胞上清液,确定了60%的硫酸铵饱和度是沉淀该拮抗物质的最佳条件;分别研究了温度、p H值、蛋白酶K、氯仿对该拮抗物质活性的影响,结果表明该拮抗物质在低温下比较稳定,在60℃以上的高温下,活性迅速降低;在酸性或碱性条件下不稳定;该拮抗物质分别加入蛋白酶K和氯仿作用后拮抗活性分别下降了60.68%、80.07%,因此,初步判断该拮抗物质为蛋白质。利用DEAE-52离子交换柱层析法分离纯化了该拮抗蛋白并进行了SDS-PAGE电泳,结果显示该拮抗蛋白的分子量为48 k Da;利用PPSQ-31A蛋白自动测序仪测定拮抗蛋白N-末端15个氨基酸序列为:His-Glu-Phe-Pro-Thr-Tyr-Lys-His-Met-Tyr-Gln-Val-Met-His-Leu。展开更多
基金Project(2010A210003) supported by Henan Province Natural Sciences Research PlanProject(0910SGYS34370-2) supported by Zhengzhou City Science and Technology Research PlanProject supported by the Youth Backbone Teacher of Universities in Henan Province Grants Plan
文摘To improve antagonistic metabolites production of Bacillus subtilis strain BS501a, physical parameters of fermentation and metal inorganic salts in medium, namely initial pH value, culture temperature, fermentation time, concentrations of CaC12, FeSO4, ZnSO4, MnSO4 and MgSO4, were optimized using one-factor-at-a-time and orthogonal tests. The results show that the optimal physical parameters of fermentation are an initial pH of 7.0, a culture temperature of 30 ~C, and a fermentation time of 48 h. The optimal concentrations of metal inorganic salts in basal medium are 10.2 mmol/L CaCl2, 0.4 mmol/L FeSO4, 3.5 mmol/L ZnSO4, 0.6 mmol/L MnSO4 and 2.0 mmol/L MgSO4. Among the metal inorganic salts, MgSO4 and MnSO4 play important roles in the improvement of the antagonistic metabolites production of B. subtilis strain BS501a; especially, MgSO4 contributes a highly significant effect. The average diameter of inhibition zone of the BS501a filtered fermentation supernatant （FFS） cultured in the optimal fermentation conditions against Magnaporthe grisea DWBJ329 reaches 71.4 mm, and there is 2.4-fold increase in antifungal activity as compared with 21.2 mm under the pre-optimized conditions.
文摘菌株AF0907是从土壤中分离到的1株对小麦赤霉病菌具有显著拮抗作用的枯草芽孢杆菌,该菌株不仅对小麦赤霉病菌具有很好的拮抗活性,对其他多种植物病原菌都具有很好的拮抗效果。为了明确菌株AF0907对赤霉病菌的抑菌机理,本研究首先使用平板对持法对拮抗物质进行定位,结果表明该菌分泌的拮抗物质主要位于细胞上清液中。采用不同饱和度的硫酸铵沉淀细胞上清液,确定了60%的硫酸铵饱和度是沉淀该拮抗物质的最佳条件;分别研究了温度、p H值、蛋白酶K、氯仿对该拮抗物质活性的影响,结果表明该拮抗物质在低温下比较稳定,在60℃以上的高温下,活性迅速降低;在酸性或碱性条件下不稳定;该拮抗物质分别加入蛋白酶K和氯仿作用后拮抗活性分别下降了60.68%、80.07%,因此,初步判断该拮抗物质为蛋白质。利用DEAE-52离子交换柱层析法分离纯化了该拮抗蛋白并进行了SDS-PAGE电泳,结果显示该拮抗蛋白的分子量为48 k Da;利用PPSQ-31A蛋白自动测序仪测定拮抗蛋白N-末端15个氨基酸序列为:His-Glu-Phe-Pro-Thr-Tyr-Lys-His-Met-Tyr-Gln-Val-Met-His-Leu。
