Advances on the Biosynthesis Mechanism of Bacterial Polysaccharides

Polysaccharide is the major component of bacterial cell that plays a significant role in the interaction between bacteria and their hosts. It aids the identification of bacteria, imparting virulence to the bacteria and adjusting host's immune response as well. Advance genomics research has deciphered several different bacterial polysaccharides sharing a common biosynthesis mechanism. The study of polysaccharides is mainly based on sequence analysis and prediction of genome in combination with metabolite analyses that still requires a detailed study. Researchers are now further focusing on their biosynthetic pathways to unveil the mechanisms underlying the diversity of these bacterial polysaccharides along with the host-pathogen interaction. It will open new doors for vaccine development and other therapeutic methods against pathogenic bacteria, and also provide technical support to control disease and cure at molecular level. This review states the mechanisms and relevant problems of biosynthesis and in vitro biosynthesis of peptidoglycan,O-antigen and capsular polysaccharides,and summarizes the application of bacteria polysaccharides in the aspects of searching for candidate antigens and controlling the targets of pathogenic bacteria and exploring genetic evolution of bacteria and biological synthesis.     

2007年12月全国饲料生产情况分析

1 生产总况 2007年12月,国内饲料生产形势急转直下,在全国多数地区生猪价格创历史新高的情况下．所有品种的饲料产量都出现了幅度不小的下降。2007年12月抽查筛选了29个省份的136家饲料企业,总产量181．5万t,同比增长16．79％,环比下降18．16％。其中配合饲料142．7万t．同比增长20．06％．环比下降20．01％;浓缩饲料32．1万t,同比增长4．82％．环比下降13．31％：添加剂预混合饲料6．6万t,同比增长12．16％,环比增长5．31％。配合饲料、浓缩饲料和添加剂预混合饲料产量与往年同期产量情况见表1。     

A peptide of foot-and-mouth disease virus serotype Asia1 generating a neutralizing antibody response, and an immunostimulatory peptide

The epitopes of the capsid of foot-and-mouth disease virus (FMDV) play important roles in the construction of highly immunogenic subunit vaccines. However few epitopes have been found for FMDV serotype Asia1. In this study we screened for epitopes of the VP1 and VP2 proteins of FMDV serotype Asia1 isolate, YNBS/58. Fragments consisting of amino acids 133-163 of VP1 and amino acids 1-33 of VP2 contained epitopes, and both induced lymphoproliferation in guinea pigs. Only the VP1 fragment induced neutralizing antibodies but the VP2 peptide dramatically increased the neutralizing antibody response induced by the VP1 peptide.     

枯草芽孢杆菌Bacillus subtilis BS1发酵培养基的优化

为提高枯草芽孢杆菌BS1发酵液中芽孢含量,通过单因素试验、正交试验及回归正交组合试验优化其发酵培养基,最终确定培养基配方为:麦芽浸粉1 g/l、黄豆粉15 g/l、CaCO36.68 g/l、MnSO40.4 g/l、MgCl22 g/l,初始pH值7.0。使用该配方,在37℃、180 r/min条件下于恒温摇床中振荡培养48 h,枯草芽孢杆菌BS1菌株发酵液中芽孢含量可达8.55×1010cfu/ml。     

对一起养殖公司使用含违禁饲料处罚案的分析与探讨

一段时期内,国内有些不法的蛋白质饲料生产企业擅自将"三聚氰胺"添加到鱼粉或饼粕类蛋白饲料中,企图以其无效的高氮(假蛋白)来达到常规检验所呈现高含量蛋白的检测结果,谋求以假乱真,获取非法利益,无疑危害了畜牧业生产。     

Comparison of Blood Physiological and Biochemical Parameters of Two Kinds of Minipigs in Different Altitudes

This study was designed to compare the blood physiological and biochemical parameters between plateau Juema minipigs and plain Bama minipigs,and provide a theoretical basis for Juema minipigs served as experimental animals in the future.The blood samples of Juema minipigs were taken in Gannan,and the blood samples of the Bama minipigs were taken in Xi'an,24 blood physiological and biochemical parameters were tested using an automatic analyzer of blood cells and biochemistry.Between the plateau Juema minipigs and Bama minipigs,there were significant differences in PLT,RDW-CV and RDW-SD (P< 0.05) and extremely significant differences in RBC,HGB,HCT,MCH,MCMH,GGT,GLU and CRE (P< 0.01).The plateau Juema minipig had an altitude acclimatization,so it was better than Bama minipig in plateau medical science.     

用发酵罐制备嗜水气单胞菌疫苗用菌液培养条件的优化

本试验探讨了用发酵罐培养嗜水气单胞菌灭活疫苗生产菌株Ｊ－１株菌液的最佳条件。分别以发酵罐和摇床在不同的培养条件下培养Ｊ－１株制备菌液,前者１２个批次,后者６个批次。比较不同的培养条件对细菌菌体数量及ＨＥＣ毒素产量的影响。结果表明：发酵罐培养优于摇床培养,以产毒素培养基于２８℃发酵罐通气培养Ｊ－１株,培养２８小时效果最佳,培养菌液含菌量达２．９×１０１０ｃｆｕ／ｍｌ,培养液上清的溶血价达２７,发酵液中残糖为０．１２ｇ／Ｌ,符合发酵工艺要求。     

断奶日龄对仔猪血液生理指标的影响

选取15窝日龄相近的三元杂交仔猪 ,按14、21、28、35日龄断奶和不断奶随机分为5组 (14E、21E、28E、35E和C) ,每组3窝。主要研究断奶与不同断奶日龄对仔猪血液生理指标的影响。主要结果为 :①哺乳仔猪从21日龄后血液中白细胞水平基本稳定 ,但14日龄时血液中白细胞水平显著低于正常水平 ;21日龄前断奶可显著降低血液中白细胞数量 ,1周后迅速提高 ,但14日龄断奶仔猪直至42日龄血液中白细胞计数(WBC)仍低于正常水平。②仔猪28日龄血液红细胞计数 (RBC)、红细胞中血红蛋白浓度 (HGB)、血液血球比容 (HCT)均达到高峰值 ,RBC、HGB、HCT均不受断奶及断奶日龄影响。③哺乳仔猪14～42日龄间血液平均红血球容积 (MCV)、红血球血红蛋白量 (MCH)呈线性下降的趋势 ,断奶对MCV、MCH测值无明显影响。     

澳大利亚墨尔本WHO流感中心对南极洲企鹅的禽流感监测

2013年,澳大利亚墨尔本世界卫生组织流感参考和研究合作中心对南极企鹅开展了禽流感病毒监测。在270份企鹅血样中,检出34份禽流感抗体阳性,抗体阳性率为16%;对301份咽喉?泄殖腔拭子进行禽流感病原学检测,检出8份阳性,病原阳性率为2.5%,并成功分离到4株H11N2禽流感病毒。企鹅携带禽流感病毒这一事实,引发了全球共同抗击全球化动物疫情的思考。