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[目的]研究化学诱变枯草芽孢杆菌对大白菜根肿病的防治效果.[方法]采用3株来自枯草芽孢杆菌XF-1的化学诱变菌株XF-1A、XF-1C和XF-1E进行大白菜根肿病的盆栽防病试验,并以MALDI-TOF-MS分析了3种抗生素的相对含量.[结果]菌株XF-1A和XF-1C防效较好,分别为68.80％和65.06％,XF-1E防效较差为42.21％.3菌株均能分泌表面活性素、伊枯草菌素和丰源素,但表面活性素和伊枯草菌素相对含量为XF-1A＞ XF-1C＞ XF-1E,XF-1A的表面活性素和伊枯草菌素分别达29.26％和35.31％,XF-1E的丰源素含量最高,达41.09％.[结论]表面活性素和伊枯草菌素含量与对根肿病防治效果存在一定的关联性 相似文献
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研究了利用大孔吸附树脂从发酵液中提取伊枯草菌素A的工艺条件。对比了不同极性大孔树脂对发酵液中伊枯草菌素A的分离效果,选择DM301型树脂作为吸附剂进行优化试验。结果表明,在25℃时,每升发酵液吸附剂用量为80 g DM301型树脂时,树脂对发酵液中伊枯草菌素A的吸附率可达100%。滤去吸附残液,采用无水乙醇解吸,每克DM301树脂解吸剂用量为10 mL时,静态解吸率达90%以上。动态吸附试验表明,发酵液的最佳上样量为6倍柱床体积,动态解吸流出液活性高度集中。该工艺简单、易操作,适用于工业化生产。 相似文献
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Karen Kinsella Cristian P. Schulthess James D. Stuart 《Soil biology & biochemistry》2009,41(2):374-379
Biological control agents like Bacillus subtilis offer an alternative and supplement to synthetic pesticides. Antibiotic production by biocontrol strains of B. subtilis can play a major role in plant disease suppression. Our current understanding of B. subtilis antibiosis comes from culture media measurements of antibiotic production and in vitro suppression of pathogens. Quantifying the antibiotic metabolite chemistry of B. subtilis biofilms growing on root surfaces provides a more accurate understanding of in vivo antibiotic production. An analytical method based on solid-phase extraction (SPE) with high-performance liquid chromatography (HPLC) and mass spectroscopy (MS) has been developed to quantify antibiotics produced by B. subtilis growing on plant roots. Cucumber (Cucumis sativus) was grown in composted soil and potting media inoculated with B. subtilis strain QST 713 (AgraQuest, USA). Two important B. subtilis antibiotics, surfactin and iturin A, were extracted from root and rhizosphere soil using acidified organic solvents followed by cleaning and concentration using SPE. HPLC and HPLC-MS were used to measure surfactin and iturin A. Rhizosphere concentrations of both antibiotics increased with plant age. For plants grown in peat-based potting media, surfactin concentrations increased from 9 μg g−1 root fresh weight (RFW) at 15 d to 30 μg g−1 RFW at 43 d. Iturin concentrations were 7 μg g−1 RFW at 15 d and 180 μg g−1 RFW at 43 d. In an initial field trial in a composted fine sandy loam, we demonstrated rhizosphere production of surfactin and iturin under competition and predation by the myriad macro- and microfauna existing in a fertile high-organic soil, with mature B. subtilis-inoculated cucumber roots yielding 33 μg g−1 RFW surfactin and 630 μg g−1 RFW iturin at 78 d. 相似文献
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为研究补料对分批发酵工艺中枯草芽胞杆菌（Bacillus subtilis）ZK8产伊枯草菌素A的影响,以“氮源+碳源+氨基酸”为补料,应用RT-qPCR技术并结合相关发酵参数分析了3个合成调控基因degQ、degUS、glnR及操纵子itu在发酵过程中的相对表达量差异。结果显示：补料-分批发酵工艺中总氮和还原糖的含量高于分批发酵工艺,生物量和效价分别提高了68.85%和36.67%;补料-分批发酵工艺中degQ、degUS和glnR 3个基因的相对表达量均高于分批发酵工艺,3个基因相对表达量的变化规律与伊枯草菌素A合成规律、操纵子itu的相对表达量变化规律一致。表明流加补料液促进了degQ、degUS和glnR的表达,为菌体提供了丰富的碳源、氮源和伊枯草菌素A的合成前体,促进了伊枯草菌素A的合成。 相似文献
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Bacillus subtilis UTB1, a biocontrol bacterium isolated from Iranian pistachio nuts, has revealed to have antagonistic activity against aflatoxin-producing Aspergillus flavus R5. The strain UTB1 produces lipopeptide compounds and is able to degrade aflatoxin B1. In this study, a random mutagenesis generated using different doses of gamma irradiation (0.1–3 KGy) was applied on B. subtilis UTB1 to improve its antagonistic activity against A. flavus R5. Five hundred bacterial colonies were selected randomly after irradiation, and their effects against A. flavus R5 were assessed in a plate assay. Forty-five colonies (9%) exhibited higher inhibition activity as compared to the non-irradiated wild type. Eight colonies out of the 45 were selected based on different polymorphism patterns obtained by repetitive element sequence polymorphism-PCR (ERIC and BOX) analyses; six of which could significantly inhibit the fungal growth utilizing washed cells and cell-free supernatants as compared to the parental strain. According to thin-layer chromatograms, the production of lipopeptides including surfactin, fengycin and iturin families increased in these six mutants. A considerable inhibition of the fungal growth was observed using bioautography analysis, which associated with iturins production. A. flavus sporulation and aflatoxin content decreased significantly in pistachio nuts treated with mutants M419 and M464 as compared to the strain UTB1. These results suggest that both mutants M419 and M464 could be promising biocontrol candidates against A. flavus in pistachio nuts. 相似文献
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为了改善烤烟生长发育水平,进一步提升烟叶品质,采用田间对比试验,对高效芽孢杆菌在烤烟上的应用效果进行了研究。结果表明：施用高效芽孢杆菌灌根处理烟株田间长势较好,在高浓度水平下上部叶开片优于常规生产,其烤后烟叶均价以及上等烟比例等经济性状较高,B1F和B2F等级烟叶的比例得到了提升,改善了上部叶的等级结构水平。在烟叶质量方面,施用高效芽孢杆菌处理后烟叶油分有增加趋势,上部烟叶烟碱含量有下降趋势,化学成分相对协调,改善了烟叶香气质和香气量感官评吸水平。综合结果表明,高效芽孢杆菌在高浓度水平下(T1和T2)灌根施用较适宜烤烟生产应用。 相似文献
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