中蜂蜜与意蜂蜜中的耐高糖酵母菌种鉴定

用加了抗生素的PDA培养基,分别分离中蜂蜜和意蜂蜜中的耐高糖酵母,再进行菌种鉴定。结果显示,中蜂蜜与意蜂蜜中的耐糖酵母为同一种,都为鲁氏接合酵母。     

白酒窖泥中酵母菌的分离鉴定及发酵特性研究

酒窖的窖泥中有非常丰富的微生物群系,包括多种酵母菌。试验针对甘肃省敦煌白酒厂提供的窖泥,采用选择培养基分离方法,筛选窖泥中的优势菌群,并对其进行生化特性研究和分子生物学鉴定。同时对白酒酒糟进行水解并对水解液成分进行测定,利用酒糟水解物作为培养基成分,研究其对已分离酵母菌生长特性的影响。结果表明:从窖泥中分离获得的优势菌群为枯草芽孢杆菌和酿酒酵母菌,酿酒酵母的最适生长温度33℃,最适生长pH值5.5,最适发酵温度30℃,最适发酵pH值5.0,在糖度为15的麦芽汁培养基中发酵最快;酒糟水解物中还原糖含量38%,氮含量0.316%,Mn、Zn、Mg、Na、K元素含量分别为1.52×10-2%、9.0×10-6%、1.34×10-6%、8.88×10-2%和0.417 8%。与OXOID市售酵母提取物相比,该酒糟水解物中的糖含量高于酵母提取物,能够满足酵母生长需求。     

影响啤酒酵母传代培养的关键因素初探

啤酒酵母主要生长在偏酸性、含糖较丰富的环境中,在其传代培养过程中会有一部分酵母死亡,甚至产生自溶。传代培养过程中不可能完全防止酵母细胞的自溶,只能控制酵母细胞自溶的限度。通过观察不同pH、装液量、酵母浸膏浓度、葡萄糖浓度、麦芽汁、紫外线照射、温度因素对啤酒酵母传代培养的影响,确定酵母菌的最佳培养方式及各影响因素的最佳值。优化后的啤酒酵母传代培养条件为:pH为5.0,温度为30℃,接种量为100 mL/L,葡萄糖浓度50 g/L,酵母浸膏浓度2.0 g/L,装液量以小于60%为宜,以增加摇瓶内的溶氧量。此外,增加摇床转速也可提高摇瓶的通气量,以40 r/min较为理想。转接酵母前,过滤去除麦芽汁培养基中析出的冷凝固物。传代培养过程中应避免紫外线辐射,以减少酵母细胞衰老、死亡及自溶的概率。     

抑制瘤胃甲烷排放的酵母菌的筛选及培养条件优化

减少瘤胃甲烷排放措施的研究已成为当前的研究热点之一。本研究以酒、面包和畜禽专用酿酒酵母产品为原材料,从中分离到三株酵母菌,将其制成冻干粉,通过体外产气试验,筛选出了一株抑制瘤胃甲烷排放效果最为显著的酵母菌株。然后以该酵母菌株作为研究对象,进行分子生物学鉴定;采用分光光度计比浊法测定该酵母菌株的生长曲线,确定菌体生长规律;并以此为依据,设计单因素试验考察该酵母菌株最适宜的生长条件。结果表明,分离得到的酵母菌株均为酿酒酵母saccharomyces cerevisiae;抑制瘤胃体外甲烷排放效果最显著的1株酵母菌分离自面包中;该酿酒酵母菌株的对数生长期为8～24h,其最佳培养条件为:生长温度30℃,pH 5.5,培养基中葡萄糖的浓度4.0%。     

不同酵母菌种富硒能力比较与发酵条件优化

将啤酒酵母、产朊假丝酵母、克鲁斯假丝酵母和葡萄汁酵母4种酵母菌株分别接种到不同硒浓度的YEPD琼脂培养基中,观察不同酵母菌株的耐硒能力;比较4株酵母菌株在相同硒浓度下的生长情况以及有机硒的转化率,选出1株富硒能力强的酵母,并对发酵条件进行优化,确定最佳的硒添加量和添加方式。结果表明:啤酒酵母的耐硒能力和富硒能力均为最强,当硒添加量为20μg/mL时,在发酵12,18和24 h分3次添加,啤酒酵母的综合富硒效果最好,活菌数为2.74×108cfu/mL,有机硒转化率为85.5%。     

蜂蜜中的酵母菌

糖液最易受酵母菌侵害 ;天然果汁 (未发酵的苹果汁、葡萄汁等 ) ,酸甜 ,最适合酵母生长 ;蜂蜜不受大多数酵母图 1　一些植物花上的酵母菌菌侵染 ,只有耐糖酵母能在像蜂蜜这样的浓糖液中繁盛。蜂蜜的发酵　蜂蜜的贮藏期比以前长 ,已成为大家关心的大事。早在 1910年就证实 :酵母     

蜂蜜的发酵和防止

花蜜中的耐糖酵母菌 ,叫做渗透酵母菌 (接合酵母菌属 ) ,只能在含糖 30 %～ 80 %的糖溶液中生长繁殖。它能使生蜜发酵 ;在含水量小于 19%的熟蜜中不活动。蜂蜜中的果糖 ,只有少量会结晶。葡萄糖结晶时形成 2种晶体 :糖晶体 ,不含水 ;葡萄糖水晶体 ,含水 9 0 9% ,低于蜂蜜含水量。因而未结晶部分 (果糖 )含水量大增 ,导致蜂蜜发酵 (15 6℃时发酵最快 )。防止蜂蜜发酵的方法如下 :1.低温冷藏 :0～ 12℃时 ,蜂蜜长期保持原状。2 .加防腐剂 :为了蜂蜜保持纯真 ,严禁使用。3.加热灭菌 :加热到 71℃ 1分钟、 6 0℃ 30分钟 ,就能杀死酵母菌。最好…     

腐植酸钠对酵母菌发酵特征的影响

试验通过在种子液培养基中添加腐植酸钠,探讨腐植酸钠对酵母菌发酵特性的影响。将腐植酸钠按不同比例添加到酵母菌种子液培养基中,以活菌数为指标筛选腐植酸钠的最适添加量;再将含有最适比例腐植酸钠的酵母菌种子液接种到稻壳粉、精料、豆粕和统糠4种固态培养基中,测定发酵产物中的活菌数,可溶性糖、可溶性蛋白和真蛋白质含量等指标。试验结果为:种子液中添加1%~4%的腐植酸钠对酵母菌的生长有明显促进作用,当腐植酸钠添加量为2%时,酵母菌活菌数最高(P0.05)。种子液中添加腐植酸钠可明显改善酵母菌在固态培养基中的发酵特性:种子液中添加腐植酸钠可显著提高4种固态发酵基质中酵母菌的活菌数,且在豆粕中提高量最大(P0.05);可显著降低精料、豆粕、统糠发酵物中的可溶性糖含量,提高稻壳粉中可溶性糖的含量,其中统糠中可溶性糖含量降低最为明显(P0.05);可显著提高精料发酵产物中可溶性蛋白质含量(P0.05),对稻壳粉、豆粕和统糠三种培养基中可溶性蛋白质含量的影响不显著(P0.05);可显著增加稻壳粉、精料、豆粕和统糠4种培养基中真蛋白质含量(P0.05),其增加率由高到低依次为:稻壳粉、精料、统糠、豆粕。结果显示,种子液中添加腐植酸钠可显著影响酵母菌固态发酵的特征,进而提高发酵效果,改善发酵饲料品质。     

玉米糖化醪作酵母菌生长培养基的研究试验

从土壤中分离到一株高转化率酵母菌株.以还原糖5.1%的玉米糖化液作培养基,经3.7升KFL-生物反应器放大试验,接种量20%、培养周期20h,成熟酵母醪生物量达42.9g/L,转化率达0.739(克细胞/克可利用糖).     

一株驯化啤酒酵母的分离鉴定及扩大培养条件的优化

为筛选一株驯化啤酒酵母,并对发酵罐扩大培养工艺进行优化,为今后大规模生产提供试验数据。于麦芽汁培养基分离挑选某株具有较好生长力的酵母菌,进行形态学、生化及分子生物学鉴定。应用正交试验设计,从摇瓶温度、pH、取样时间及发酵罐的转速、装液量、接种量等方面进行优化。结果表明,驯化酵母菌株形态学、生化鉴定证明该菌株属于酵母属;发酵罐扩大培养最佳工艺为:转速200r/min,接种量50mL/L,装液量4.5L,此条件下酵母活菌含量为2.8×10~8 CFU/mL。驯化前后表现一致,没有发生变异。优化啤酒酵母菌的发酵罐扩大培养工艺,为下一步规模化生产提供理论参考。     

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.     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …