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
[Objective] This study aimed to isolate and purify the antifungal protein against Fusarium oxysporum f. sp niveum （FON） from Bacillus subtilis XG-I. [Method] The crude protein was obtained by using fractional precip...[Objective] This study aimed to isolate and purify the antifungal protein against Fusarium oxysporum f. sp niveum （FON） from Bacillus subtilis XG-I. [Method] The crude protein was obtained by using fractional precipitation with am- monium sulfate, then chromatography using both DEAE-Sepharose FF anion ex- change and Sephacryl S-100 gel filtration columns was adopted for further purifica- tion of the protein, followed by MALDI-TOF-MS analysis of the structure of the at- tained protein which was antagonistic to FON. [Result] The result from MALDI-TOF- MS analysis suggested that the antifungal protein extracted from strain XG-1 was highly homologous to the flagellin （gi114278900） deriving from B. subtilis, with a pro- tein score of 248 and a coverage rate of 63%. It was thus speculated that this an- tagonistic protein was a kind of flagellin with a molecular mass of 30.6 kD. [Conclusion] The results from this study provide theoretical basis for clarifying the mechanisms of the action of strain XG-1 as well as important references for the preven- tion and control of watermelon Fusarium wilt.展开更多
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。
基金Supported by the Research Fund for Mid-career and Young Scientists of Education Department of Hubei Province(Q2011130)~~
文摘[Objective] This study aimed to isolate and purify the antifungal protein against Fusarium oxysporum f. sp niveum （FON） from Bacillus subtilis XG-I. [Method] The crude protein was obtained by using fractional precipitation with am- monium sulfate, then chromatography using both DEAE-Sepharose FF anion ex- change and Sephacryl S-100 gel filtration columns was adopted for further purifica- tion of the protein, followed by MALDI-TOF-MS analysis of the structure of the at- tained protein which was antagonistic to FON. [Result] The result from MALDI-TOF- MS analysis suggested that the antifungal protein extracted from strain XG-1 was highly homologous to the flagellin （gi114278900） deriving from B. subtilis, with a pro- tein score of 248 and a coverage rate of 63%. It was thus speculated that this an- tagonistic protein was a kind of flagellin with a molecular mass of 30.6 kD. [Conclusion] The results from this study provide theoretical basis for clarifying the mechanisms of the action of strain XG-1 as well as important references for the preven- tion and control of watermelon Fusarium wilt.
