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为了了解培养温度对嗜热链球菌抑制法检测结果的影响,试验取装有浓度为1 mg/L的嗜热链球菌液体管,在6个不同温度下分别进行培养基划线培养与菌落计数,并进行加样牛奶的抗生素检测。结果表明:在49℃下嗜热链球菌抑制法检测效果最好,菌落生长情况最好。说明在49℃下进行试验有利于结果的判定,提高了嗜热链球菌抑制法检测的准确性。 相似文献
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酸奶生产用直投式乳酸菌发酵剂研究 总被引：2，自引：0，他引：2
对酸奶常用发酵剂菌种德氏乳杆菌保加利亚乳杆菌亚种S-1、嗜热链球菌G1208的高密度细胞培养条件,低温真空冷冻干燥中抗冷冻保护剂的选择等进行了研究。结果发现,德氏乳杆菌保加利亚乳杆菌亚种S-1在改良MRS培养基中的最佳培养条件为:培养温度43℃,起始pH值6.0,最高活菌数为1.2×109cfu/mL;采用3%蔗糖+3%海藻糖+10%β-环糊精+10%甘油+1%酵母膏+10%脱脂奶作为冻干保护剂,经低温冷冻干燥后,存活率为40.8%。嗜热链球菌G1208的最佳培养条件为:培养温度37℃,起始pH值7.0,对培养基配方进行优化后,最高活菌数为1.7×109cfu/mL;采用3%海藻糖+1%酵母膏+10%脱脂奶作为保护剂经低温冷冻干燥后,存活率可达96%。 相似文献
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为了解培养温度对嗜热链球菌抑制法检测结果的影响,本研究取嗜热链球菌浓度为1mg/L的液体管在6个不同温度下分别进行平板划线培养与菌落计数并进行加样牛奶的抗生素检测。结果表明,49±1℃下嗜热链球菌抑制法检测效果最好,菌落生长情况最好,有利于结果的判定,可提高嗜热链球菌抑制法检测的准确性。 相似文献
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采用选择性培养基分离酸乳中的保加利亚乳杆菌和嗜热链球菌,并利用生理生化和糖发酵实验结合16S rDNA同源性分析对分离所得菌株进行鉴定,获得保加利亚乳杆菌和嗜热链球菌分离菌株。利用脉冲场凝胶电泳（pulsed field gel electrophoresis,PFGE）分别对保加利亚乳杆菌和嗜热链球菌分离株进行基因分型。结果表明：所检测的酸乳样品中均含有保加利亚乳杆菌和嗜热链球菌;仅有2 种酸乳的嗜热链球菌为同一菌株,其余酸乳中的保加利亚乳杆菌及嗜热链球菌均为不同菌株。PFGE可以对保加利亚乳杆菌和嗜热 相似文献
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以感官评定值为脱臭指标,以DPPH自由基清除率为抗氧化肽指标,采用混合菌种发酵法,菌种组合(青春双歧杆菌∶嗜热链球菌)比例为1∶3,确定脱除柞蚕蛹蛋白臭味和制备抗氧化肽的工艺。并在单因素基础上,采用Design-Expert8.0软件,利用Box-Behnken设计实验,用响应面分析法优化各因素及其交互作用确定最佳工艺条件。结果表明:发酵温度为42℃、发酵时间为23 h、菌种接种量为4%、pH为6.8条件下,感官评定值为4.65,DPPH自由基清除率为93.78%。 相似文献
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奶牛瘤胃需氧及兼性厌氧菌的PCR-16S rDNA鉴定及日粮的影响 总被引：1，自引：0，他引：1
设计9个精料梯度的日粮饲喂干乳期成年荷斯坦奶牛,并对其瘤胃液中的部分细菌进行了分离,PCR-16S rDNA鉴定和动态检测。结果显示,以瘤胃液为原料,采用人工培养基共分离到56株细菌,并对7株具代表性的细菌进行了PCR扩增,经序列同源性比较,最终把细菌鉴定为牛链球菌（A0625、A1212、0131）、蜡样芽孢杆菌（0113）、地衣芽孢杆菌（0091）、短小芽孢杆菌（0083）和嗜热链球菌（0123）。同时还发现随精料浓度的增加,牛链球菌、芽孢杆菌及嗜热链球菌的数量均呈不同程度的上升趋势。结果表明不同精料浓度的日粮对奶牛瘤胃需氧及兼性厌氧菌有着不同程度的影响,其中对牛链球菌影响最大,从系统发育分析可知所分离细菌虽未形成新的细菌进化枝,但牛链球菌和嗜热链球菌的核苷酸序列仍发生了多处碱基突变。 相似文献
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嗜热链球菌的检验培养基(M17)的改良 总被引：6，自引：0，他引：6
M17培养基是酸奶中嗜热链球菌计数的重要培养基，它也是从政奶或牛奶中分离嗜热链球菌的常用培养基。该培养基培养嗜热链球菌时间长。如采用改良M17培养基不仅能提高酸奶中嗜热链球菌计数的准确度，而且能缩短嗜热链球菌培养时间，提高工作效率。通过实验得出改良M17培养基的配方为：胰蛋白胨质量分数0．5％．鱼蛋白胨0．5％．牛肉膏0．5％，酵母漫膏0．25％，抗坏血酸0．05％，硫酸镁0．025％。甘油1％。磷酸二氢钾O．5％。乳糖0．3％。琼脂1．1％。 相似文献
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搅拌型冬枣汁酸奶加工工艺研究 总被引：2，自引：0，他引：2
以鲜乳为原料，经乳酸菌发酵制成凝固型酸牛奶后，添加一定比例的冬枣汁搅拌、冷却罐装，即得风味清香、口感好、营养价值丰富的合格搅拌型冬枣汁酸奶。研究表明：以接种3％～5％的保加利亚乳杆菌和嗜热链球菌（按1：1比例）、发酵温度41～42℃、发酵时间3～4h为最佳组合。 相似文献
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本试验采用改进的邻苯三酚自氧化测定法、正交设计法和生物数学分析法对酸羊奶中ＳＯＤ活性进行了研究。结果表明：在单菌种间，其酸羊奶中ＳＯＤ活性是嗜热链球菌（１７．２）〉保加利亚杆菌（１６．５）〉乳酸链球菌（１５．０）〉嗜酸杆菌（１４．２），有链球菌（１６．１）大于杆菌（１５．４）的趋势。在混合菌种间，其酸羊奶中ＳＯＤ活性是以嗜热链球菌和保加利亚杆菌按１：１比例、采用４３℃发酵温度的组合为最高，由于菌种 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献
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Billinghurst RC Brama PA van Weeren PR Knowlton MS McIlwraith CW 《American journal of veterinary research》2004,65(2):143-150
OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis. 相似文献