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排序方式: 共有1319条查询结果,搜索用时 15 毫秒
71.
为短短芽孢杆菌(Brevibacillus brevis)DFG菌株的开发应用提供参考,采用不同化学物质处理方法结合琼脂打孔法研究不同培养基、接种量和发酵时间对其发酵液抑菌活性的影响,并在此基础上研究温度、蛋白酶、酸碱、紫外线照射和反复冻融等因素对其抑菌物质稳定性的影响。结果表明:NA培养基培养的DFG菌株其发酵液对金黄色葡萄球菌(Staphylococcus aureus)的抑制作用最强,抑菌圈直径达2.4cm;发酵液经100℃处理30min,抑菌率仍达65%;对酸碱也具有较强的稳定性;经紫外线照射和反复冻融后性质稳定;对胃蛋白酶、胰蛋白酶及蛋白酶K不敏感,可用有机溶剂对短短芽孢杆菌DFG菌株抑菌物质进行部分萃取。 相似文献
72.
山梨酸酯的合成与抗菌作用研究 总被引:4,自引:0,他引:4
采用直接酯化法,将山梨酸与四种醇反应,合成了山梨酸甲酯、乙酯、丙酯、丁酯。合成产率达到60%-70%。这几种化合物均表现出良好的抗菌活性,与山梨酸相比较,可延长微生物生长适应期8-20h,并明显降低微生物生长量。 相似文献
73.
LI Qi-qin MENG Xian-ying WU Xue LIN Wei DUAN Cheng-jie FENG Jia-xun TANG Ji- liang 《中国农业科学(英文版)》2006,5(5):363-369
Two antimicrobial substances produced by Bacillus subtilis strain B 11 were purified by boiling, DEAE 52 anion exchange chromatography and aluminum oxide adsorption chromatography, These purified substances showed only one spot on silica gel thin layer chromatography (TLC). Antimicrobial assays showed that antimicrobial substances A and B inhibited the growth of plant pathogens such as Fusarium oxysporum Schl f.sp. niveum, Rhizoctonia solani, Ralstonia solanacearum and Xanthomonas oryzae pv. oryzae. In addition, antimicrobial substance B could also inhibit the growth of Magnaporthe grisea. These two antimicrobial substances were resistant to proteolytic enzymes and temperature as high as 121℃. 相似文献
74.
新疆干旱区土壤放线菌拮抗植物病原真菌的研究 总被引:2,自引:0,他引:2
采用常规方法研究了塔里木盆地的和田和阿克苏两地区土壤中的放线菌对植物病原真菌的拮抗性.结果表明:两地区3种类型的土壤中均有拮抗放线菌存在,占全部供试放线菌的20.4%;和田地区的拮抗放线菌出现的比例高于阿克苏地区;林地土壤中拮抗放线菌株数占相应来源放线菌总数的比例最高,其次为耕作土壤,荒漠土壤中拮抗放线菌比例最低.菌株GTW-03抗植物病原真菌范围较广,抑制效果好,具有开发天然农用杀菌剂的巨大潜力. 相似文献
75.
采用超声波法在碱性条件下用取代苯酚与氯乙酸合成取代苯氧乙酸,并测试其抑菌活性.共合成了3个取代苯氧乙酸衍生物,即对氯苯氧乙酸,邻氯苯氧乙酸,对溴苯氧乙酸,用IR,^1 H NMR,UV及元素分析确证了其结构.同时选取大肠杆菌、沙门氏菌、枯草芽孢杆菌和金黄色葡萄球菌等四种细菌对所合成的取代苯氧乙酸类化合物测试其最小抑菌浓度(MIC).抑茵活性表明:对氯苯氧乙酸和对溴苯氧乙酸的抑菌谱较广,而邻氯苯氧乙酸的抑菌谱较窄. 相似文献
76.
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78.
Black corals (BC) have been used for a long time in Chinese medicine, and may have some pharmaceutical functions when used as material for cigarette holders in southeast China. This study is aimed to investigate the bioactivities of volatile constituents in BC and to explore the folklore behind the use of BC cigarette holders (BCCHs). We extracted the volatile constituents of BC by supercritical fluid extraction (SFE) with carbon dioxide (CO2-SFE), then identified and analyzed the constituents by gas chromatography-mass spectrometry (GC-MS). In total, 15 components were reliably identified in BC and found to be biologically active. These included triethyl phosphate, butylated hydroxytoluene, cedrol, n-hexadecanoic acid, squalene, and cholesterol. Meanwhile 13 inorganic elements (P, Ca, Mg, S, B, Si, Fe, Cu, Zn, Ba, etc.) were determined by inductively coupled plasma spectrometer (ICPS). In the bioactivity tests, the BC extract (BCE) showed a scavenging activity of 2,2-diphenyl-1-picrylhydrazyl free radicals and hydroxyl radicals by phenanthroline-Fe (II) oxidation and moderate inhibition of Gram-positive microorganisms. The antioxidant and antimicrobial activities of BC, which are related to the active chemical composition, may explain the perceived benefit for cigarette smokers who use BCCHs. 相似文献
79.
80.
The aim of this study was to investigate the prevalence of acquired antimicrobial resistance in the resident intestinal microbiota of cats and to identify significant differences between various cat populations. Escherichia coli, Enterococcus faecalis, E. faecium and Streptococcus canis were isolated as faecal indicator bacteria from rectal swabs of 47 individually owned cats, 47 cattery cats and 18 hospitalised cats, and submitted through antimicrobial sensitivity tests. The results revealed that bacteria isolated from hospitalised and/or cattery cats were more frequently resistant than those from individually owned cats. E. coli isolates from hospitalised cats were particularly resistant to ampicillin, tetracycline and sulfonamide. Both enterococci and streptococci showed high resistance to tetracycline and in somewhat lesser extent to erythromycin and tylosin. Most E. faecium isolates were resistant to lincomycin and penicillin. One E. faecalis as well as one E. faecium isolate from hospitalised cats showed 'high-level resistance' (MIC > 500 microg/ml) against gentamicin, a commonly used antimicrobial agent in case of human enterococcal infections. The results of this research demonstrate that the extent of acquired antimicrobial resistance in the intestinal microbiota of cats depends on the social environment of the investigated population. It is obvious that the flora of healthy cats may act as a reservoir of resistance genes. 相似文献