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微生物脂肽的研究概况 总被引：1，自引：0，他引：1
微生物脂肽(lipopeptide)又名脂酰肽(acylpep-tide),由微生物代谢产生,其种类繁多、结构复杂,是一类由脂肪链和肽链组成的具有两亲结构的微生物次级代谢产物。它具有良好的表面活性,能增加憎水烃类的生物可获得性,激发烃的生物降解,可与部分重金属结合并去除被污染物质中的重金属,是一类重要的生物表面活性剂。由于其特殊的分子结构与多种生物学功能,微生物脂肽在医药、食品、化妆品及微生物采油等多个领域中有重要的应用前景[1-2]。此外,大多数微生物脂肽都具有抗微生物的作用,也常被称为抗生素。微生物脂肽在饲料营养中也具有开发价值和应… 相似文献
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益生菌在马属动物中的应用及研究进展 《畜牧与饲料科学》2022,43(4):39-47
益生菌作为一种活的微生物饲料补充剂,不仅能提高动物生产性能、增强免疫力,还有维持胃肠道菌群平衡、净化胃肠道环境的功能,在预防和治疗动物腹泻、调节宿主免疫功能等方面发挥着重要作用。益生菌具有安全性高、无残留、无耐药性等特点,可作为替抗产品。益生菌广泛应用于马属动物并取得良好的效果。综述了益生菌及相关活性物质的作用机理及马用益生菌产品存在的问题和应用前景,旨在为马用益生菌产品的开发利用提供参考。 相似文献
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乳酸杆菌是人和动物肠道中重要的益生菌。益生菌进入肠道后,能够黏附定植并形成黏膜生物屏障,帮助肠道抵御各种致病菌的感染,维持肠道的正常功能。乳酸杆菌的黏附是由其表面蛋白、脂磷壁酸和胞外多糖等黏附素与宿主细胞表面的受体相结合的过程。为深入研究黏附机制,本文主要对乳酸杆菌黏附肠道上皮的黏附素和受体等方面进行综述。 相似文献
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复合益生菌发酵饲料是由几种益生菌、发酵剂等共同作用制成的一类饲料,利用益生菌产生的各种酶降低饲料中大分子物质及抗营养因子,产生有益代谢产物、改善饲料的品质、提升饲料的适口性,更利于动物对饲料营养成分的消化与吸收。复合益生菌发酵饲料可以调节动物肠道菌群,维持肠道微生态的稳定,一定程度上抑制有害菌的生长,促进有益菌的增殖。因此益生菌发酵饲料在动物生产中具有广阔的发展前景。文章在介绍益生菌发酵饲料原理的基础上重点阐述了复合益生菌发酵饲料在动物生产中的应用,为复合益生菌发酵饲料的开发与应用提供理论参考。 相似文献
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随着人民生活水平的提高，伴侣动物如犬、猫等受到越来越多家庭的喜爱，对于宠物粮食的需求也由传统粮食逐渐向能够改善其健康的功能粮方面转变。益生菌是一类能够在动物体内定植的活性微生物，具有调控肠道菌群平衡、维持动物机体健康、促进营养吸收等作用。文章对益生菌的定义、菌株选择标准及其在宠物粮食中的应用进行了综述，分析了不同加工方式可能对益生菌的影响，旨在科学合理地加工含益生菌的功能粮食，保证其生物活性，为改善宠物健康提供思路。 相似文献
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采用抑菌圈实验方法测定不同蜜粉源植物蜂王浆对革兰氏阴性菌和革兰氏阳性菌的抑菌作用。试验用蜂王浆分别是产浆型意蜂和产蜜型意蜂所产的油菜蜂王浆和荆条蜂王浆;受试菌株包括革兰氏阳性细菌(金黄色葡萄球菌和枯草芽孢杆菌)和革兰氏阴性细菌(沙门氏菌和大肠杆菌)。研究结果显示:油菜蜂王浆对革兰氏阳性菌有明显的抗菌作用,且产浆型意蜂所产的油菜蜂王浆对受试细菌的抑菌效果优于产蜜型意蜂品系所产油菜蜂王浆,两种意大利蜂所产的油菜蜂王浆对金黄色葡萄球菌的抗菌作用优于枯草芽孢杆菌;油菜蜂王浆对革兰氏阴性菌的抑菌作用也较强,两种蜂王浆对沙门氏菌的抑菌效果优于大肠杆菌;产浆型意蜂所产的荆条蜂王浆对金黄色葡萄球菌和枯草芽孢杆菌的抑菌效果均高于产蜜型意蜂所产的荆条蜂王浆,然而,二者的抑菌效果弱于油菜蜂王浆。研究表明,不同蜜粉源植物的蜂王浆抗菌效果不同,油菜蜂王浆对受试革兰氏阳性菌和革兰氏阴性菌的抗菌效果均比荆条蜂王浆强,产浆型意蜂所产的蜂王浆对受试菌的抗菌效果优于产蜜型意蜂所产的蜂王浆。 相似文献
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I Politis X Zhao B W McBride J H Burton J D Turner 《American journal of veterinary research》1991,52(8):1208-1213
The type of plasminogen activator (PA) produced by bovine milk macrophages has been determined. Macrophages produce a PA protein with molecular weight of 28,000 and isoelectric point of 8.5, and with enzymatic activity independent of fibrin. These characteristics are identical to those reported for bovine urokinase-PA. Although blood monocytes and milk macrophages produce PA after stimulation with lipopolysaccharide, mammary macrophages are clearly limited in their ability to release PA. At maximal stimulation, 78% of the PA produced by milk macrophages remained cell-associated. In marked contrast, blood monocytes released 76% of the PA produced into the culture medium. Macrophages isolated from mastitic quarters produced higher (2.5 times) amounts of PA, compared with those produced by macrophages isolated from healthy quarters. However, in both cases, macrophages were unable to secrete the protein already produced. The limited PA secretion by milk macrophages might be a residual function of a differentiated macrophage population. 相似文献
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Balb/c mice were infected with two abortigenic strains of equine herpesvirus-1 (EHV-1) by intranasal inoculation. The inoculation of one strain produced subclinical disease while the other produced a disease characterised by weight loss, constitutional signs, and death in the most severely affected animals. When pregnant mice were infected by the same method of inoculation, one strain of virus produced premature parturition; both strains produced fetal abnormalities. In some cases, virus could be detected in the aborted fetuses by means of virus isolation and immunofluorescent staining. 相似文献
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F A Mann C Wagner-Mann J A Allert J Smith 《American journal of veterinary research》1992,53(5):856-860
Intranasal (IN) and intratracheal (IT) oxygen administration techniques were compared by measuring inspired oxygen concentrations (FIO2) and partial pressures of arterial oxygen (PaO2) in 5 healthy dogs at various IN (50, 100, 150, and 200 ml/kg of body weight/min) and IT (10, 25, 50, 100, 150, 200, and 250 ml/kg/min) oxygen flow rates. Intratracheal administration of oxygen permitted lower oxygen flow rates than IN administration. Each IT oxygen flow rate produced significantly higher FIO2 and PaO2 than the corresponding IN flow rate. An IT oxygen flow rate of 25 ml/kg/min produced FIO2 and PaO2 values equivalent to those produced by an IN oxygen flow rate of 50 ml/kg/min. An IT oxygen flow rate of 50 ml/kg/min produced FIO2 and PaO2 values equivalent to those produced by IN oxygen flow rates of 100 and 150 ml/kg/min. All IT oxygen flow rates greater than or equal to 100 ml/kg/min produced FIO2 and PaO2 values that were greater than FIO2 and PaO2 values produced by IN oxygen flow rates of 200 ml/kg/min. The lowest flow rates studied (50 ml/kg/min, IN, and 10 ml/kg/min, IT) produced PaO2 capable of maintaining 97% hemoglobin saturation, which should be adequate for most clinical situations. Arterial blood gas analysis and FIO2 measurements are necessary to accurately guide oxygen flow adjustments to achieve the desired PaO2 and to prevent oxygen toxicity produced by excessive FIO2. 相似文献
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Specific pathogen free cats were infected by two feline calicivirus isolates of different plaque type, an extra-large plaque (ep) former and a minute plaque (mp) former. A comparison was made of the disease produced when these isolates were administered by either aerosol or direct intranasal instillation. With both isolates, aerosol infection produced lesions and gave rise to virus replication throughout the respiratory tract. The effects of intranasal infection were more confined to the upper respiratory tract and oropharynx. By both routes of infection the disease produced by the mp virus was clinically and pathologically less severe than that produced by the ep virus. 相似文献
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Virendra Singh MVSc Amarpal MVSc PhD Prakash Kinjavdekar MVSc PhD & Hari P Aithal MVSc PhD 《Veterinary anaesthesia and analgesia》2009,36(1):77-85
ObjectiveTo evaluate and compare the effect of epidural bupivacaine on analgesia produced by epidural xylazine or medetomidine in buffaloes.Study designProspective, blinded study.AnimalsTen male buffalo calves (6-8 months of age; body weight 70-90 kg) were used on two occasions to conduct a total of 20 investigations.MethodsCaudal extradural analgesia was produced in four buffalo calves each by the injection of either xylazine (0.05 mg kg?1), medetomidine (15 μg kg?1) or 0.5% bupivacaine (0.125 mg kg?1), or combinations of xylazine and bupivacaine (0.05 and 0.125 mg kg?1), or medetomidine and bupivacaine (15 μg kg?1 and 0.125 mg kg?1) at the first intercoccygeal extradural space. Analgesia was tested using deep pinprick stimuli.ResultsExtradural administration of xylazine or medetomidine resulted in complete analgesia of the tail, perineum, inguinal region and the upper parts of the hind limbs, which was faster in onset and longer in duration in the medetomidine group than in the xylazine group. Addition of bupivacaine increased the intensity of the analgesia produced by xylazine, but not that produced by medetomidine. All the drugs caused mild to moderate ataxia, but signs of sedation were apparent only in animals which received xylazine or medetomidine. The extradural injections of all the drugs caused significant decrease in heart rate (p = 0.024), respiratory rate (p = 0.026) and rectal temperature (p = 0.036) from the respective baseline values, but the differences between the groups were not significant.ConclusionsMedetomidine produced a longer duration of analgesia than that produced by xylazine. Bupivacaine prolonged the analgesia produced by xylazine, but the analgesia produced by the combination of medetomidine and bupivacaine was not superior to that produced by medetomidine alone.Clinical relevanceBupivacaine may be used to prolong the extradural analgesia produced by xylazine, but not that produced by medetomidine in buffaloes. 相似文献
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An attenuated recombinant avian leukosis virus (ALV) produced by recombinant DNA techniques was examined for its ability to provide resistance to Rous sarcoma virus (RSV) challenge. Specific-pathogen-free chicken embryos (18-day incubation) and hatched chicks inoculated with recombinant ALV produced significantly smaller tumors than sham-inoculated controls upon challenge with RSV 2 weeks postinoculation; inoculation with RAV-1 produced similar results. Specific-pathogen-free hens inoculated with recombinant ALV produced viral-protein-specific antibody that was transmitted to 100% of the progeny, as detected by enzyme-linked immunosorbent assay. Progeny of the inoculated hens produced significantly fewer tumors than sham-inoculated controls upon challenge with RSV at hatch, indicating that maternal antibody may be a factor in resistance to tumor development. 相似文献
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采用灰色关联分析法 ,对青海省 6个饲料厂生产的育肥猪饲料进行了综合质量评价 ,结果表明 :丁香集团新禾工贸公司生产的育肥猪饲料关联系数最大 ,为 0 .7796;大通县饲料厂、多巴镇扎麻隆村饲料厂、湟源县饲料公司、青海饲料厂、德令哈工务段责任有限公司生产的育肥猪饲料的关联系数分别为 0 .741 3、0 .672 1、0 .61 31、0 .5871和 0 .4378。 相似文献
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By the use of the electrophoretic casein precipitating inhibition test (CPI-test) the serological relationship between proteolytic enzymes produced by different species within the genera Clostridium and Bacillus has been tested. The proteases produced by Clostridium botulinum types A, B, C, D and F cross-reacted with each other. Clostridium botulinum strain 84 was inhibited by antiproteases produced against Clostridium sporogenes, Clostridium botulinum types C and F (protease F I and F II), but not by antiproteases against Clostridium botulinum types B and F (protease II), Clostridium bifermentans and Clostridium perfringens. The protease of the newly described Clostridium botulinum strain 89 (type G) was inhibited by Clostridium sporogenes antiprotease, but not by any of the other antiproteases. It is not possible to differentiate between Clostridium botulinum, Clostridium sporogenes and Clostridium perfringens by use of serological differentiation of their proteolytic enzymes. The protease of Clostridium bifermentans is not serologically related to any of the species tested in this investigation. Proteases produced by different Bacilli were not inhibited by antiproteases from Clostridium botulinum types B, C and F, Clostridium sporogenes, Clostridium bifermentans, and the two strains of Clostridium perfringens tested. This investigation indicates a serological relationship between proteases from different Clostridium species, but not a serological relationship between proteases produced by the Clostridium species and Bacillus species tested. 相似文献
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探索柞蚕产卵量的遗传规律,对柞蚕产卵性状的遗传改良具有重要指导意义。以柞蚕新品种582和宽青为对交亲本分别配制F1和F2,用主基因-多基因分离分析法研究其产卵量的遗传规律,结果表明:柞蚕杂交组合582×宽青的产卵量由2对主基因控制,同时受微效多基因修饰,其中,主基因遗传率占43.84%,多基因遗传率占5.81%。值得注意的是,环境因素对柞蚕产卵量的影响较大,环境方差占总表型方差的比率达50.35%,因此,环境因素对产卵量的影响不容忽视。研究结果提示,在排除环境因素干扰的情况下,通过固定有利于提高产卵量的主基因,完全可以对柞蚕品种的产卵性状进行遗传改良。 相似文献