共查询到19条相似文献,搜索用时 109 毫秒
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本研究旨在通过高温处理和常规厌氧菌分离法从健康肥猪粪便中分离芽孢杆菌,并通过培养性状、生化试验、PCR、肠道耐受、抗菌活性和接种试验动物等方法鉴定筛选性状稳定、优良的益生性芽孢杆菌。结果显示,共分离到6株芽孢杆菌,其中1株巨大芽孢杆菌、1株死谷芽孢杆菌、2株解淀粉芽孢杆菌和2株枯草芽孢杆菌;分离菌对多黏菌素和青霉素耐药性较强,对其他12种常用药物较敏感,对致病性大肠杆菌和金黄色葡萄球菌的抑菌效果较好;4种芽孢杆菌均可在酸性、高胆盐和高温条件下生存,特别是巨大芽孢杆菌和枯草芽孢杆菌耐受能力较强;分离的芽孢杆菌对小鼠均无致病性,其中巨大芽孢杆菌和死谷芽孢杆菌有较明显的促进试验动物生长的作用。结果提示,巨大芽孢杆菌和死谷芽孢杆菌可作为益生性芽孢杆菌的初步选择。 相似文献
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【目的】 探究引发浙江省某养殖场大黄鱼发病的病原及其致病性和耐药情况。【方法】 无菌条件下剖检发病大黄鱼,取其肝脏和肾脏组织,划线分离培养细菌,通过形态学观察、生理生化试验、16S rRNA基因序列分析鉴定分离菌的种属特性,通过人工感染和组织切片制备评价分离菌对大黄鱼的致病性,最后通过药敏纸片法检测分离菌的耐药性。【结果】 分离菌在培养基上外观为表面凸起、光滑和边缘整齐的黄色圆形菌落;革兰氏染色后光学显微镜下呈现出单个分散或成对分布的红色短棒状杆菌;该分离菌可在麦康凯琼脂上生长,可利用葡萄糖产酸;16S rRNA基因序列相似性分析及系统进化树显示,该分离菌与金黄杆菌相似性高达97.0%以上并聚为一类。动物回归试验结果显示,分离菌可引起大黄鱼的肝脏、肾脏和脾脏发生明显病变,半数致死量为6.32×104 CFU/mL,表明其对大黄鱼具有较强致病性;药敏结果显示,分离菌对阿米卡星和左氧氟沙星敏感,对庆大霉素、新霉素和红霉素中度敏感,对头孢克肟、氨苄西林、卡那霉素、呋喃唑酮等耐药。【结论】 本研究分离了大黄鱼源致病株金黄杆菌,并通过其致病性和耐药性研究为金黄杆菌引发水产动物发生病害的防控和治疗提供参考。 相似文献
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1株产碱性木聚糖酶的芽胞杆菌的分离鉴定及其相关研究 总被引:5,自引:1,他引:5
分离到1株产碱性木聚糖酶的革兰氏阳性菌株,通过菌落形态及16srDNA序列同源性分析,确定该菌株为短小芽孢杆菌。生长条件和产酶条件研究结果显示,最适温度和pH分别为50℃和pH8·0。培养基优化试验显示在有机和无机混合氮源条件下(NH4NO30·57%;牛肉膏1%;蛋白胨0·5%;酵母提取物0·5%;木聚糖0·5%)木聚糖酶产量达到最高(180U/mL)。酶学试验表明最适反应条件为50℃,pH8~9;在pH9的条件下,孵育120min时仍具有75%的活力,表明该酶具有较强的碱耐受性。 相似文献
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In order to select probiotic strains with probiotic potential isolated from Tibetan sheep,fresh excreta of the healthy female Tibetan sheep was processed with 90 ℃ water-curing treatment for 5 min,and Bacillus with resistance were screened.The morphological,physiological and biochemical characteristics and 16S rDNA sequence of the Bacillus were comprehensively analyzed and identified.Biochemical characteristics were studied by using antimicrobial test,acid resisting tests and bile salt resisting tests,hydrolytic enzyme test and other methods.The results showed that the Bacillus SWUN-G43 isolated from fresh excreta of Tibetan sheep had a significant antibacterial effect on E.coli and Salmonella.Through analysis and identification,the Bacillus SWUN-G43 was Bacillus pumilus.Its survival rate was 50.43% under the environment of pH 2.0 and 44.35% under the environment of 0.3% bile salt.It could produce protease and cellulase and was sensitive to 12 kinds of commonly used antibiotics.By studying,the Bacillus pumilus(SWUN-G43) had a certain degree of resistance and potential probiotic ability.Besides,the strain didn't contain R-plasmid and would not cause horizontal transmission of antibiotic resistance in the intestinal microecosystem.It also had the potential to be developed as a micro ecological additive. 相似文献
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为获得来源于藏绵羊的益生菌菌株,对健康母藏绵羊新鲜粪便进行90 ℃水浴处理5 min以筛选具有抗逆性的芽孢杆菌,再综合形态学、生理生化特征及16S rDNA序列分析进行鉴定,通过抑菌试验、耐酸、耐胆盐试验及产水解酶试验等方法对其生物学特性进行研究。结果显示,从新鲜粪便样品中分离到的芽孢杆菌菌株SWUN-G43对大肠杆菌和沙门氏菌有明显的抑菌效果,通过分析鉴定其为短小芽孢杆菌,该菌株在pH 2.0的环境中存活率为50.43%,在0.3%胆盐环境中存活率为44.35%,可产生蛋白酶和纤维素酶,对12种常用的抗生素具有很高的敏感性。从试验结果可分析出该短小芽孢杆菌(SWUN-G43)有一定的抗逆性和潜在的益生能力,且该菌株不含耐药质粒,不会在动物肠道微生态系统中造成抗生素抗性的水平传递,具有作为微生态添加剂开发的潜力。 相似文献
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ZHONG Luo-hua DENG Shun-zhou ZHANG Wen-bo GAO Yang-gen XUE Rui LUO Feng WANG Jian-zhong 《中国畜牧兽医》2017,44(2):521-529
This study was aimed to separate Bacillus from healthy pig feces by high temperature treatment method and conventional anaerobic bacteria isolated method, and through the cultivation of traits, biochemical tests, PCR, bowel tolerance, antibacterial activity and vaccinated animals and other screening methods to identify stable properties and probiotic Bacillus. As a result, a total of six strains of Bacillus, which were one strain of huge Bacillus, one strain of Death Valley Bacillus, two strains of Bacillus amyloliquefaciens and two strains of Bacillus subtilis. Isolates were resistant to polymyxin and penicillin, were more sensitive to the other 12 kinds of commonly used drugs, and had better bacteriostatic action to pathogenic E.coli and Staphylococcus aureus. Four kinds of Bacillus were available under acidic, high temperature conditions and bile salts, in particular Bacillus megaterium and Bacillus subtilis were strong tolerance. Those isolated Bacillus were not pathogenic to mice, wherein Bacillus megaterium and Death Valley Bacillus had a more significant role in promoting the growth of animals. Finalized, the Bacillus megaterium and the Death Valley Bacillus could initially be as probiotic Bacillus choice. 相似文献
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从健康肉鸡的粪便中分离出一株BF3芽孢杆菌,经培养特征、形态观察、生理生化试验以及16SrDNA序列分析相似度为99%,确定该菌株为枯草芽孢杆菌,对该株芽孢杆菌对肠道致病菌的拮抗作用进行研究。结果表明BF3菌株在培养过程中,可以抑制鸡白痢沙门氏菌和鸡大肠杆菌的生长。拮抗作用的强弱与芽孢杆菌和致病菌的接种时间有关。先接种芽孢杆菌后接种致病菌,拮抗作用最强;芽孢杆菌和致病菌同时接种次之;先接种致病菌后接种芽孢杆菌,拮抗作用最弱。并且BF3菌株代谢产物对鸡白痢沙门氏菌和鸡大肠杆菌具有非常明显的拮抗作用。 相似文献
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【目的】试验旨在寻找1株性能稳定、环境耐受性强的凝结芽孢杆菌菌株,以在实际生产中发挥其替抗功能。【方法】本研究采集160日龄健康海兰褐蛋鸡的粪便样本,进行细菌分离纯化,并对分离菌进行形态学特征观察、生理生化鉴定、16S rDNA测序分析。通过绘制该菌的生长动力曲线确定其生长规律;利用耐酸、耐胆盐试验分析该菌株的耐受性;通过单因素试验对分离菌株的培养条件进行优化。【结果】分离菌在普通培养基上长出表面粗糙、不规则的灰白色菌落,镜检为杆状、芽孢端生的革兰氏阳性菌。结合生化试验及16S rDNA基因序列分析综合鉴定该菌株为凝结芽孢杆菌,命名为NJ001。生长动力曲线表明,7~24 h为该菌株的对数生长期,24 h活菌数达到顶峰,凝结芽孢杆菌NJ001的最佳培养时间为24 h;耐受性试验结果显示,该菌株pH 3.0温育2 h存活率为59.5%,pH为4.0时存活率达到87.6%以上,对酸有较强耐受力;0.3%胆盐处理2 h存活率为54.0%,胆盐浓度升至0.5%时存活率仍有50%以上,该菌对胆盐有较强的耐受性。单因素试验结果发现,该菌的最佳培养温度为40℃,接种量2%,初始pH 7.0,摇床转速... 相似文献