新书阅读

《家兔的营养与饲料配制》；《现代生物饵料培养及开发利用》。     

牛卵母细胞体外成熟培养研究进展

作为胚胎生物工程技术研究的基础之一的牛卵母细胞体外成熟培养技术自上世纪30年代起至今,许多科学研究人员在牛卵母细胞体外生长、发育领域做了大量工作,对牛卵母细胞培养条件进行了广泛而深入地研究,并取得了较大的进展,目前牛卵母细胞体外成熟培养技术体系已建立,但在卵母细胞成熟机理、成熟调控方面尚存在许多尚未阐明的问题和一些亟待解决的问题。本文从卵母细胞的来源、卵母细胞体外培养条件、培养液的完善及卵母细胞成熟判定方法等方面详尽介绍了当前牛卵母细胞体外培养技术的研究进展。     

生防菌株Men-myco-93-63发酵培养条件研究

对生防链霉菌Men-myco-93-63进行了摇瓶培养条件试验。结果表明,培养温度30℃,培养基初始pH值7.5,500ml三角瓶装液100ml,摇床转速200r/min为最适摇瓶发酵培养条件。在优化的培养条件基础上进行了摇瓶中代谢情况的测定,并在摇瓶试验的基础上进行了30L发酵罐试验,为进一步发酵规模化生产奠定了基础。     

促卵泡素与促黄体素对猪卵母细胞体外成熟的影响

促卵泡素(FSH)与促黄体素(LH)是参与卵母细胞成熟的最重要的蛋白质激素,在猪卵母细胞体外成熟培养中使用较多。大部分研究已经证实了促性腺激素(FSH、LH)在猪卵母细胞体外成熟培养中的重要作用。为进一步探讨FSH与LH对猪卵母细胞体外成熟的影响,确定其对猪卵母细胞体外成熟的作     

Isolation and Identification of a Variant Porcine Epidemic Diarrhea Virus and the Immune Efficacy of Its Inactivated Vaccine

This study was aimed to isolate a mutant strain of porcine epidemic diarrhea virus and prepare a PEDV inactivated vaccine with high valence by suspension culture process for immunizing against PEDV effectively in China.200 small intestines and theirs contents of diarrhea piglets died of diarrhea,collected from many large-scale pig farms in China,were detected by RT-PCR and sequenced,a mutant strain of porcine epidemic diarrhea virus was selected and put on the suspension-cultured Vero cells in a 2 L reactor for virus isolation and continuous cell culture,the harvested virus suspension,which was identified and determined TCID₅₀,was inactivated by formaldehyde and mixed with aluminum hydroxide gel adjuvant to prepare PEDV inactivated vaccine.After its physical behavior,stability viscosity,sterility test were checked out,the safety and immune efficacy were studied by immunizing the pregnant pigs and theirs piglets.The results were as follows:86 samples were detected positive in 200 samples,cytopathy occurred after the mutant strain samples screened were passaged to 5th generation,the virus suspension was harvested in 10th generation and identified as a mutant strain of PEDV,named PEDV-GF10 strain.The virus titer of harvested virus suspension was measured up to 1×10^8.0 TCID₅₀/mL after concentrated.After the vaccine was checked out,the sows,40 and 25 days before delivery in experimental groups,were injected into Xuehai acupoint with 4 mL vaccine and the pigs in blank group were free of immunifications.The results showed that there were no obvious differences in the production status of the sows in experimental groups and blank group and the temperature of theirs 3-day-old healthy piglets injected different doses of vaccine,and the vaccine was safe to the sows and piglets.Forty 3-day-old piglets producted by pregnant sows in experimental groups and blank group were randomly selected and taken 4 mL 1×10^8.0TCID₅₀/mL F10 virus culture.The PEDV morbidity of piglets in blank group was 100% after injection and the antibodies were negative;10% piglets in blank group had mild diarrhea symptoms,the protection rate was up to 90%,antibody of passive immunity in piglets lasted for more than 35 days.Virus titer of mutant strain of PEDV-GF10 improved a lot by suspension cell culture,the PEDV-GF10 inactivated vaccine was safe,and could effectively prevent and control the variation strain of PEDV in China.     

饲养层细胞对胚胎干细胞的影响及其分离培养的影响因素

胚胎干细胞及其相关研究是生命科学领域中最有活力、最有影响力、最有应用前景的研究方向之一，它与遗传工程，转基因技术等相结合具有重大的理论意义与实践价值。饲养层细胞在胚胎干细胞分离培养的过程中起着异常重要的作用。作者结合实践经验就饲养层细胞对胚胎干细胞的影响进行了概述，介绍了饲养层细胞的分类，并分析了饲养层细胞分离培养的影响因素。     

小鼠4、8-细胞胚胎单卵裂球体外培养体系的研究

以CZB为基础培养液,培养小鼠4、8-细胞胚胎单卵裂球,研究葡萄糖、牛磺酸和猪输卵管上皮细胞共培养在其体外发育中的作用。结果表明:牛磺酸添加与否对4、8-细胞胚胎单卵裂球的囊胚发育率分别为29%、30%和14%、14%,无显著性差异(P>0.05)。添加葡萄糖后,4、8-细胞胚胎单卵裂球的囊胚发育率分别为36%和19%,有显著提高(P<0.05)。含有葡萄糖而牛磺酸的添加与否对4、8-细胞胚胎单卵裂球的囊胚发育率分别为36%、38%和19%、20%,无显著性差异(P>0.05)。各组内4、8-细胞胚胎单卵裂球形成的囊胚细胞数分别为(10.44±1.24～(12.43±1.18)和(7.57±0.97)～(8.48±1.16),均无显著性差异(P>0.05)。4、8-细胞胚胎单卵裂球与猪输卵管上皮细胞共培养,其囊胚发育率分别为47%和26%,囊胚细胞数分别为(17.57±1.13)和(11.43±0.92),均高于单一培养(P<0.05)。     

胚胎干细胞的研究进展

胚胎干细胞来源于附植前胚胎的内细胞团或附植后胎儿的原始生殖细胞具有发育全能性的细胞。本文从它的研究概况、生物学特性、胚胎干细胞的分离培养与建系等方面做一概述。     

DGGE/TGGE技术在瘤胃微生物生态学研究中的应用

在分子生物学技术出现之前，人们对微生物的认识大多数是靠纯培养，或者靠直接形态观察来获得的。动物的胃肠道是一个复杂的生态环境，特别是反刍动物的瘤胃需要严格的厌氧环境，过去对瘤胃微生物的研究主要是一些经典的方法如享氏滚管法（Hungate．1969）和最大可能计数法（Dehority等，1989）。因为微生物形态简单，缺乏明显的外部特征，所以胃肠道中的大多数微生物由于难于模拟其生长繁殖的真实条件而很难培养。能培养的微生物只是天然微生物中的一小部分，     

细菌的活的非可培养状态及其在动物微生态制剂生产中的应用

目前，由于多数益生菌（乳酸菌、双歧杆菌等）不耐热，在60℃几乎全部被杀灭，经受不住饲料制粒与膨化过程中高温高压的破坏作用，因而活菌数量少、菌种活性低就成了生产动物微生态制剂公认的难题。尽管采用冻干技术、稳定化技术、微胶囊化技术及包膜等先进工艺，但也克服不了高成本、繁制备等缺点。而且这类产品在饲喂过程中不经常单独使用，而是与抗生素、矿物质预混剂、多维预混剂、浓缩料等配合使用，这样也会使活菌数显著下降，并且产品贮存条件要求较高，需密封、低温、避光、冷藏等等。因此，利用细菌的活的非可培养状态（viable but noneuhurablestate，VBNC）性质，筛选VBNC菌种将会为动物微生态制剂的生产提供新的办法和解决思路。