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为了取得比较理想的禽用微生态制剂菌种,用BL和乳酸杆菌选择性培养基从SPF鸡嗉囊和盲肠中分离乳酸菌,通过生化试验、乳酸纸层析等方法进行鉴定。结果,从SPF鸡嗉囊和盲肠中分离到产酸能力较强的细菌3株,经鉴定为2株乳酸杆菌(LactobaccillusPlanterum)、1株粪链球菌(Enterococcusfaecium)。 相似文献
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本研究从海南文昌椰子树上分离得到26株奇异根串珠霉菌,选取在PDA培养基上培养性状差异明显的3个分离株,进行了生物学特性研究。结果表明：3株分离株可以在15～35 ℃范围内生长和产孢,但对30 ℃以上高温的适应性有较大差异。3株分离株均可在查彼克培养基（Czapek）上生长和产孢。在供试碳源中,3株菌菌丝生长最佳碳源均为可溶性淀粉,BR2和GF924产孢最适碳源亦是可溶性淀粉,TR924产孢最适碳源为甘露醇;菌丝生长最佳氮源是氯化铵,BR2最适产孢氮源是硝酸钾,TR924和GF924在查彼克培养基（Czapek）上产孢量最大。3株分离株在pH4～11的范围内均能很好的生长和产孢。 相似文献
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采用琼脂扩散法测定粪肠球菌发酵上清液对大肠埃希菌K88的抑菌活性,从而确定产enterocin E5细菌素粪肠球菌的发酵条件。结果表明,粪肠球菌E5产细菌素的发酵培养基为MRS培养基,最适温度为37℃,最适起始pH值6.5,最佳接种量2%,种龄14 h,发酵时间16 h,最佳培养基组分氮源为1%胰蛋白胨、0.5%酵母浸粉,最佳碳源为1%葡萄糖、0.5%蔗糖,0.1%Tween-80有利于enterocin E5的产生。这是分离自北京优良商品猪黑六产enterocin E5粪肠球菌的首次报道。 相似文献
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为了分离出可用于研制猪用微生态制剂的乳酸杆菌菌株。选择齐齐哈尔市龙江县,甘南县,富裕县及泰来县等地区相关猪场,采集21～35日龄健康仔猪肠道粪样15份。选用MRS琼脂培养基分离培养乳酸杆菌,通过分离菌株的形态特征和培养特性筛选出革兰氏阳性,厌氧,无芽孢杆菌16株。再通过生理生化鉴定法,确定5株为乳酸杆菌。其中,嗜酸乳杆菌2株,植物乳杆菌2株,干酪乳杆菌1株。 相似文献
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研究旨在筛选高黏附特性的鸡源乳酸菌，评价其主要生物学特性。试验应用MRS琼脂培养基从SPF鸡十二指肠、盲肠及小肠分离菌株，通过形态学观察、生理生化试验进行初步筛选，随后采用ERIC-PCR与16S rRNA基因序列分析相结合的方法对分离菌株进行种属鉴定，并对分离鉴定的乳酸菌株进行黏附能力、耐酸与耐胆汁特性、生长曲线、体外传代能力等生物学特征进行分析。结果显示：在34株分离菌株中鉴定到9种基因型，其中7株为罗伊氏乳杆菌、2株为约氏乳杆菌。菌株编号为C7的罗伊氏乳酸杆菌对HT-29细胞黏附率为（32.3±1.67）%，显著高于商品化乳酸乳球菌MG1363株和乳杆菌BNCC182567株以及除S3株外的其他分离株（P<0.05）；在pH2.0～5.0条件下存活率均高于100%，在40%与60%新鲜鸡胆汁作用下存活率分别为（116.67±11.89）%和（102.33±10.87）%，在体外连续传代10代仍能保持良好的活力。结果表明分离获得的C7分离株为罗伊氏乳酸杆菌，具有高黏附特性、耐酸与耐胆汁特性，该菌株为研究益生菌制剂及口服疫苗表达载体奠定了初步基础。 相似文献
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Enterococci are well-known producers of antimicrobial peptides--bacteriocins (enterocins) and the number of characterized enterocins has been significantly increased. Recently, enterocins are of great interest for their potential as biopreservatives in food or feed while research on enterocins as alternative antimicrobials in humans and animals is only at the beginning. The present study provides a survey about the occurrence of enterocin structural genes A, P, B, L50B in a target of 427 strains of Enterococcus faecium (368) and Enterococcus faecalis (59) species from different sources (animal isolates, food and feed) performed by PCR method. Based on our results, 234 strains possessed one or more enterocin structural gene(s). The genes of enterocin P and enterocin A were the most frequently detected structural genes among the PCR positive strains (170 and 155 strains, respectively). Different frequency of the enterocin genes occurrence was detected in strains according to their origin; the strains from horses and silage showed the highest frequency of enterocin genes presence. All possible combinations of the tested genes occurred at least twice except the combination of the gene of enterocin B and L50B which possessed neither strain. The gene of enterocin A was exclusively detected among E. faecium strains, while the gene of enterocin P, B, L50B were detected in strains of both species E. faecium and E. faecalis. In conclusion, a high-frequency and variability of enterocin structural genes exists among enterococci of different origin what offers a big possibility to find effective bacteriocin-producing strains for their application in veterinary medicine. 相似文献
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Screening of the enterocin genes and antimicrobial activity against pathogenic bacteria in Enterococcus strains obtained from different origins 总被引：1，自引：0，他引：1
Theppangna W Murase T Tokumaru N Chikumi H Shimizu E Otsuki K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(12):1235-1239
Antimicrobial activities of 139 Enterococcus isolates (48 E. faecium and 91 E. faecalis) obtained from canine feces, boiler meat samples, swine feces, wild waterfowl feces, and human feces were examined against respective bacteria, including Streptococcus pyogenes, Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes, Salmonella Enteritidis, and Escherichia coli. Bacteriocin (BAC) production assay revealed that the antimicrobial activity against at least one of 6 indicator strains (BAC+ phenotype) was found in 51 (37%) isolates (29 E. faecium and 22 E. faecalis). Twenty-four of 46 isolates positive for at least one of the enterocin structural genes (entA, entB, entL50AB, and cylL) showed a BAC+ phenotype. The existence of other enterocins or nonenterocin factors was implied because the BAC+ phenotype was detected in a total of 27 Enterococcus isolates that had none of the enterocin genes tested. The antimicrobial activity against Gram-negative strains (Salmonella Enteritidis and E. coli) was detected in the 6 Enterococcus isolates that had either the entA, entB, entL50AB or cylL genes. Moreover, the proportion of the antimicrobial activity against L. monocytogenes among the cylL-positive E. faecalis isolates showing beta-hemolysis (10/16) was significantly (p<0.01) higher than among those lacking beta-hemolysis (2/15). The results suggested that certain characteristics are likely to be associated with the antimicrobial activity against specific organisms. 相似文献
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JIANG Jing Ao-ri-ge-le WANG Chun-jie ZHANG Yan ZHAO Chen-he WU Hong-jun HAO Jian-gang 《中国畜牧兽医》2016,43(2):444-449
To study the physicochemical properties extracted from koumiss of Lactobacillus plantarum DSM20174 bacteriocin,we purified the Lactobacillus plantarum DSM20174 bacteriocins and got the bacteriocin crude extractions after ammonium sulfate precipitation and dialysis.After purification with Sephadex G-100 gel column chromatography,bacteriocin specific activity apparently increased,reaching 154.70 AU/mL,yield was 43.5%.We detected the effects of purified Lactobacillus plantarum DSM20174 bacteriocin on bacteriostatic action of wild bovine pathogenic E.coli O78 by Oxford cup method under 3 different treatments.The results showed that:①In five groups of temperature treatments,the bacteriostatic action decreased with the increase of temperature,bacteriostatic actions of all groups were significantly different (P<0.05).Even after treatment at 121 ℃ 30 min,antimicrobial diameter was 14.90 mm.② After Lactobacillus plantarum DSM20174 bacteriocin were treated with pH 2.0 to pH 12.0,the higher of pH,the smaller of antibacterial diameter.The inhibitory effect of groups were significantly different (P<0.05) except pH 9.0 and pH 10.0.③Lactobacillus plantarum DSM20174 bacteriocins were treated by trypsin,pepsin and papain,antibacterial diameter apparently changed,bacteriostatic action was significantly different (P<0.05) before and after treatment.The results suggested that Lactobacillus plantarum DSM20174 bacteriocins were better antibacterial substances,but not thermal stability substances.It had a relatively wide pH range,and the smaller of pH,the stronger of its antibacterial activity,the antibacterial activity had been enhanced at optimum growth pH.It was not protease stability substances. 相似文献
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为研究从酸马奶中提取的植物乳杆菌DSM20174细菌素的理化特性,本试验提纯植物乳杆菌DSM20174细菌素,经过硫酸铵沉淀、透析后得到细菌素粗提液,再利用SephadexG-100凝胶柱层析进行纯化后,细菌素的比活力明显增加,达到154.70 AU/mL,得率为43.5%.采用牛津杯法测定纯化的植物乳杆菌DSM20174细菌素在3种不同方式处理下对牛源野生致病性大肠杆菌O78抑菌效果的影响.结果显示:①植物乳杆菌DSM20174细菌素在5组温度处理下,随着温度的升高抑菌作用降低,各组抑菌作用差异显著(P<0.05).即使121 ℃处理30 min后,抑菌直径仍达14.90 mm.②植物乳杆菌DSM20174细菌素在pH 2.0~12.0由低到高的11组酸碱处理下,pH越大抑菌直径越小,且除了pH 9.0和pH 10.0之间差异不显著(P>0.05)外,其余各组抑菌作用均差异显著(P<0.05). ③植物乳杆菌DSM20174细菌素经胰蛋白酶、胃蛋白酶、木瓜蛋白酶3种酶处理后抑菌直径变化明显,处理前后抑菌作用均差异显著(P<0.05).结果表明植物乳杆菌DSM20174细菌素是较好的抑菌活性物质,但不是热稳定性物质;具有较广泛的pH适用范围,且pH越小时其抑菌活性越强,在最适生长pH时抑菌活性有所增强;不是蛋白酶稳定性物质. 相似文献
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抗菌肽又称抗微生物肽,是生物先天性免疫的重要组成成份,具有广谱抗菌作用并且不易产生耐药性。抗菌肽作为饲料添加剂有促生长、防病以及可提高机体免疫力的作用;作为兽药可治疗各类细菌性、病毒性疾病以及各类寄生虫疾病;抗菌肽在畜禽养殖上的功能正在逐渐被开发,有望被开发成为抗生素替代品而广泛应用于畜禽养殖业。本文就家畜来源的抗菌肽从结构、用途和作用机制以及在畜牧兽医领域中的应用进行系统的分析与讨论。 相似文献
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本试验旨在探讨植物乳杆菌(Lactobacillus plantarum)对玉米秸秆和水稻秸秆奶牛瘤胃体外发酵特性的影响。采用单因子随机区组试验设计,分别以玉米秸秆和水稻秸秆为发酵底物,分析不同添加水平[0(对照)、0.25×107、0.50×107和0.75×107CFU/m L]植物乳杆菌对发酵底物体外发酵产气量(1、2、4、6、12、24、36、48 h)、产气参数、干物质降解率(DMD)、中性洗涤纤维降解率(NDFD)、发酵液挥发性脂肪酸(VFA)、氨态氮(NH3-N)浓度及p H的影响。结果表明:添加植物乳杆菌能显著提高玉米秸秆发酵初期产气速率和产气量(1~24 h)(P0.05),以添加0.75×107CFU/m L效果最为理想;添加植物乳杆菌能显著提高水稻秸秆体外发酵后期(36~48 h)产气量(P0.05),而以添加0.25×107CFU/m L效果最为理想。随着植物乳杆菌添加水平的增加,2种底物体外发酵液NH3-N浓度均呈现显著的线性增加效应(P0.05)。不同植物乳杆菌添加水平对2种底物体外发酵NDFD、DMD、发酵液VFA(乙酸、丙酸、异丁酸、丁酸和戊酸)浓度以及p H均无显著影响(P0.05)。由试验结果推断,添加植物乳杆菌能促进玉米秸秆和水稻秸秆体外发酵及其氮代谢,同时对维持p H的稳定平衡具有积极作用,最佳添加水平分别为0.75×107和0.25×107CFU/m L。 相似文献
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