一株解淀粉芽孢杆菌的特性及抑菌活性研究

试验旨在对一株牛瘤胃源解淀粉芽孢杆菌的生长曲线、耐酸性和耐胆酸盐性等特性进行分析，同时对该菌发酵产物的抑菌活性和抑菌活性稳定性进行测定。采用生长速率法测定该菌生长曲线，活菌计数法测定耐酸性和耐胆酸盐性等特性，牛津杯法测定抑菌活性和抑菌活性稳定性。结果显示，该菌生长4 h时进入对数生长期，20 h后生长趋于稳定，进入生长稳定期；同时该菌表现出较好的耐酸性，在pH 3.0~7.0时存活率为23.8%~90.6%；有较好的耐胆酸盐性，在0.1%~0.4%的胆酸盐中存活率为64.2%~83.6%。以大肠杆菌（Escherichia coli）、副溶血弧菌（Vibrio parahemolyticus）、藤黄八叠球菌（Sarcina lutea）和产气杆菌（Aerogenes）等细菌和黑曲霉（Aspergillus niger）、黑根霉（Rhizopus nigricans）等霉菌作指示菌进行抑菌试验发现，该菌的发酵产物具有抑菌活性，同时其抑菌活性物质的耐热性和耐酸性较好。本试验通过对该解淀粉芽孢杆菌的特性进行研究发现，该菌具有耐酸、耐胆酸盐等特性；其抑菌活性及抑菌稳定性较好，具有耐酸碱及耐高温特性。     

抑霉乳酸菌的筛分及其抑菌特性研究

试验旨在获取生物抑霉的优良菌株以及为质量安全青贮饲料生产提供高效菌剂。从青贮饲料、酸奶以及奶豆腐中分离纯化出乳酸菌和霉菌,并且通过双层平板法对具有抑制霉菌活性的乳酸菌菌株进行筛选,测定其上清液抑霉效果;采用蛋白酶处理和高温处理法分析乳酸菌抑霉的有效成分。结果表明:分离筛选的乳酸菌和霉菌经鉴定为植物乳杆菌和黄曲霉菌,且植物乳杆菌对黄曲霉菌的生长有明显抑制作用。蛋白酶处理对乳酸菌无细胞上清液的抑菌活性有不同影响,而加热处理并不改变其抑菌效果。研究表明,植物乳杆菌对黄曲霉菌生长有明显的抑制作用,推测其抑菌活性物质为蛋白质、肽类等,并且这些抑菌活性物质的热稳定性较高。     

阿魏酸对青贮主要有害微生物作用效果及机理研究

为研究阿魏酸对青贮主要有害微生物的抑菌活性及其作用机理,本试验以青贮中酵母菌、丁梭菌、乙酸菌、霉菌作为指示菌株,通过滤纸片法研究阿魏酸对指示菌株抑菌活性,分析其对微生物生长曲线、阿魏酸剩余含量、胞外蛋白含量与溶液电导率的影响,探讨抑菌机理。结果显示：0.6%的阿魏酸对酵母菌、丁梭菌、乙酸菌、霉菌抑菌效果显著|阿魏酸使菌株胞外蛋白分别降低了16.4%、6%、8.2%、10.8%,胞外溶液电导率分别降低了96、40、337、165 us/cm。阿魏酸对青贮主要有害微生物均具有一定的抑制效果,其抑菌机理可能是通过延长指示菌株的适应期,破坏蛋白质的合成,影响指示菌株对培养基的利用能力,从而干扰菌株生理代谢活动。 [关键词] 阿魏酸|抑菌|微生物|青贮     

构树叶提取物对金黄色葡萄球菌的抑制作用及机理研究

为了研究构树叶提取物的抑菌作用及其机理,以金黄色葡萄球菌为供试菌,采用牛津杯法测定构树叶提取物的抑菌效果,通过测定供试菌生长曲线、细胞膜渗透性和蛋白质合成来研究构树叶提取物的抑菌机理。结果表明,构树叶水提取物和75%乙醇提取物抑菌圈直径分别为17.5和18.0 mm,最小抑菌浓度均为6.8 mg/mL,最小杀菌浓度均为12.50 mg/mL。构树提取物能显著抑制金黄色葡萄球菌蛋白质合成,从而抑制其生长,但对其细胞膜的通透性影响不大。因此,构树叶提取物通过抑制金黄色葡萄球菌蛋白质合成发挥其抑菌效果。     

木霉菌对草坪草病原菌的抑菌效果及其机理初步研究

木霉菌是自然界中普遍存在的拮抗微生物,多种木霉菌对植物病原菌具有重要的生防价值。为挖掘出防治草坪草病害的生防菌剂,采用对峙培养法测定了4株木霉菌株对14种草坪草病原菌的拮抗作用,通过显微镜观察、玻璃纸法及粗提液抑菌试验研究了其抑菌机理。研究结果表明,供试木霉菌对所有供试病原菌均有拮抗作用,其中菌株SQ-1Q-18抑菌效果最佳,对玉蜀黍丝核菌和地衣状伏革菌的拮抗等级为I级,抑制率高达100%,对灰葡萄孢菌、地毯草炭疽菌和立枯丝核菌的拮抗等级为Ⅱ级,抑制率大于80%,且对供试病原菌的平均抑制率高达72.8%。进一步研究菌株SQ-1Q-18的抑菌机理发现,该菌株在培养基上产生抑菌圈侵占病原菌的生长空间,覆盖和深入病原菌内部并与其相互缠绕使得病原菌菌丝变细、缢缩甚至断裂,或直接穿入病原菌菌丝内部吸取营养致使菌丝细胞溶解,也可产生拮抗物质,其中玻璃纸法中对草坪草币斑病菌、球黑孢霉及地衣状伏革菌的相对抑制率分别高达91.77%、89.80%和79.59%;粗提取液对草坪草币斑病菌和佩立金平脐蠕孢的抑制率分别为43.60%和42.91%。经鉴定,SQ-1Q-18为哈茨木霉。研究结果为高效防治草坪草真菌病害的生防菌剂的研制、开发提供了科学资料。     

海南沿海羊栖菜和海带不同提取物的抑菌活性

本实验以金黄色葡萄球菌(St aphyl occoccus aureaus Rosenbach)、大肠埃希菌(Escheri-chi a col i)2种需氧型细菌作为供试细菌,用圆形纸片法对羊栖菜和海带的无菌水、乙醚和乙醇提取物进行抑菌试验。结果表明:采用水提法、95%乙醇浸提取法和乙醚索氏提取法均能从羊栖菜和海带中提取出活性物质,提取回收率依次为水提法>乙醇提法>乙醚提法;比较对羊栖菜和海带3种不同提取方法得出:乙醇提取物对两种菌体的抑菌活性相对水提物和乙醚提取物较好,且乙醇提取物乙酸乙酯相对水相抑菌活性较好;比较羊栖菜和海带乙醇提取物乙酸乙酯相的MIC得出:海带对大肠埃希菌和金黄色葡萄球菌的MIC相对羊栖菜较低,抑菌效果较好。     

阿散酸-TMP的制备与体外抗菌活性研究

以阿散酸和甲氧苄啶(TMP)为原料,制备阿散酸-TMP,采用IR、熔点对其进行了表征;正交试验确定了最优反应条件为:反应温度80 ℃,反应时间3 h,反应物料比1.1∶1(阿散酸∶TMP)。通过体外抑菌试验来测试其抑菌效果,结果表明,阿散酸-TMP对5种供试菌的抑菌圈直径都在20 mm以上,显著大于阿散酸与TMP的混合物(P＜0.05);阿散酸-TMP对埃希氏大肠杆菌、金黄色葡萄球菌、鸡白痢沙门氏菌、福氏志贺氏菌、藤黄微球菌的MIC分别为32、64、256、32、128 μg/mL,均小于阿散酸与TMP的混合物。阿散酸-TMP对供试菌的抑菌效果好于阿散酸、TMP及阿散酸与TMP的混合物。     

甘草内生真菌分离及其抑菌活性初探

为了解药用植物甘草(Glycyrrhiza uralensis)内生真菌资源多样性及其抑菌活性特征,通过组织块法对内生真菌进行分离,并选择小麦全蚀病菌（Gaeumannomyces graminis var.tritici）、枸杞黑果病菌（Colletotrichum gloeosporioides）、番茄灰霉病菌（Botrytis cinerea）、黄瓜枯萎病菌（Fusarium oxysporium f.sp.cucumeris）、黄瓜立枯病菌（Rhizoctonia solani）5种植物病原真菌和枯草芽孢杆菌（Bacillus subtilis）、大肠杆菌（Escherichia coli）、金黄色葡萄球菌（Staphylococcus aureus）、铜绿假单胞菌（Pseudomonas aeruginosa）4种细菌作为供试指示菌,采用对峙法和改进的菌块法测定抑菌活性。试验结果显示,从甘草根、茎、叶中分离出20株内生真菌,其中根部最多,占分离菌株总数的65.0%,其次为茎部,叶部最少;经形态学初步分类鉴定归于2目2科5属,梭孢霉属为优势菌属,占分离菌株总数的70.0%;在分离的内生真菌中有15株菌对1种或1种以上供试植物病原真菌有不同程度的抑制作用,为分离内生真菌总数的75.0%,19株菌对1种或1种以上供试细菌有不同程度的抑制作用,为分离内生真菌总数的95.0%;有7株内生真菌对枯草芽孢杆菌拮抗活性差异显著（P＜0.05）,有 8株内生真菌对金黄色葡萄球菌拮抗活性差异显著,有3株内生真菌对大肠杆菌拮抗活性差异显著,有1株内生真菌对革兰氏阴性铜绿假单胞菌拮抗活性差异显著,其中菌株RLEFR015对番茄灰霉病菌、金黄色葡萄球菌拮抗活性差异显著,菌株RLEFR010对大肠杆菌、金黄色葡萄球菌拮抗活性差异显著,菌株RLEFR002对枯草芽孢杆菌、金黄色葡萄球菌供试细菌拮抗活性差异显著;菌株RLEFR015、RLEFR002、RLEFR010均为梭孢霉属,为高活性菌株。甘草内生真菌具有多样性和抑菌活性,多数菌株对供试病原真菌和病原细菌具有拮抗活性,对革兰氏阳性金黄色葡萄球菌和革兰氏阳性枯草芽孢杆菌拮抗活性较强,预示着甘草内生真菌具有重要的资源价值。     

放线菌D01对马铃薯4种病原真菌的抑菌作用

采用PDA平板对峙法、生长速率法等方法,研究了放线菌D01对马铃薯干腐病菌、马铃薯黑痣病菌、马铃薯炭疽病菌和马铃薯早疫病菌4种病原真菌的抑菌活性。结果表明,放线菌D01对4种病原真菌均表现出显著的抑菌活性,发酵液抑菌率均在70%以上;经放线菌处理后,病原真菌的基内菌丝不同程度的发生了畸变;放线菌D01对供试靶标真菌均有显著的拮抗作用,其中对马铃薯干腐病菌和马铃薯黑痣病菌的持续抑菌作用最强。     

蟛蜞菊挥发油成分体外抗菌活性研究

试验旨在研究蟛蜞菊挥发油能否作为天然安全优质的抗生素替代品而广泛应用于畜禽生产。通过水蒸汽蒸馏法获得蟛蜞菊挥发油,并研究测定其对畜禽养殖中大肠杆菌、金黄色葡萄球菌、葡萄球菌、沙门氏菌等常见致病菌的抑制效果。结果表明,蟛蜞菊挥发油对4种供试菌种都具有显著的抑制效果,且随着挥发油浓度的增大,其抑菌活性增强。     

商会自治的基石——商会自治规范研究

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。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

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。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

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.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

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。     

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.     

Mechanism of Action of Probiotic Function of Lactobacilli

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.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

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.