猪源乳酸菌的分离、筛选、鉴定及产酸性能的研究

试验旨在分离、筛选出具有强抗逆性、产酸能力强的同源菌株。从28日龄断奶健康仔猪粪便分离得到30株乳酸菌,应用体外筛选法,筛选出在pH值2.5处理2h后的菌株13株;将此13株菌株通过浓度为0.2%胆盐后剩7株。采用牛津杯法进行抑菌试验,从7株菌中筛选出对大肠杆菌、沙门氏菌有较强抑菌作用的4株,分别为R11、R15、R18、R22,对此4株菌株进行产酸试验验证,都表现出强的产酸能力。对这4株菌进行鉴定性试验,结果R11为屎肠球菌,R15为鸡肠球菌,R18为嗜酸乳杆菌,R22为口乳杆菌。     

苜蓿粉发酵用乳酸菌的筛选及特性研究

为筛选调制优质动物苜蓿青贮饲料的优良乳酸菌,本试验以从郑州地区9个苜蓿样品中分离得到的乳酸菌为试验材料,经抗菌活性、生长特性及产酸特性筛选菌株,根据16S r DNA序列,结合生理生化特征进行菌种鉴定,并通过发酵苜蓿粉考察菌株的发酵特性。结果表明,从分离的19株乳酸菌中筛选到4株具有高抗菌活性的菌株,其中菌株ZZU 457和ZZU 466在MRS液体培养基中生长及产酸性能较好,均能够耐受6.5%的盐浓度环境;菌株ZZU 457耐受10~45℃,以及p H为3.5的环境,而菌株ZZU 466能够耐受5~50℃,以及p H为4.0的环境;苜蓿粉发酵结果表明接种ZZU 457或ZZU 466在发酵18 h内均能快速产酸,其中接种ZZU 466的苜蓿粉发酵36 h时p H值达到4.2;结合理化特征及16S r RNA序列分析结果,ZZU 466被鉴定为融合魏斯氏菌。优良菌株ZZU 466在苜蓿青贮饲料调制加工中具有潜在的应用价值。     

牧草青贮型乳酸菌的分离、筛选及鉴定

为了筛选性状优良的益生性乳酸菌,并为制备优良的牧草青贮型发酵菌剂奠定基础,试验采用MRS-Ca CO3平板从青海高海拔地区牧草或青贮牧草中筛选乳酸菌,同时对其进行形态学鉴定和生理生化特性、产酸能力、生物学特性及16S rRNA序列分析。结果表明:从燕麦草中共筛选获得水解圈直径比值较大的菌株12株,其中植物乳杆菌4株,发酵乳杆菌3株,干酪乳酸杆菌2株,屎肠球菌1株,嗜酸乳酸杆菌2株;植物乳杆菌YZ05和屎肠球菌YZ06是同型发酵乳酸菌,与其他菌株相比,具有很强的产酸能力和良好的益生特性。说明植物乳杆菌YZ05和屎肠球菌YZ06是制备青贮饲料的优良菌剂。     

蒙古族传统酸马奶中嗜酸乳杆菌发酵特性研究

从蒙古乌兰巴托周边牧民家庭采集的5个酸马奶样品中,分离并鉴定出30株嗜酸乳杆菌,从中筛选出4株具有潜在益生特性的进行发酵特性研究.结果表明：37℃发酵24h,嗜酸乳杆菌发酵乳平均产酸为147.40T,pH值在3.69～3.53之间,粘度在366.3～384.3cP之间,12%TCA可溶性氮为6.262L～9.241mmol/L;4℃冷藏过程中,发酵乳pH降低缓慢,乳糖含量呈降低趋势,且仍有较高活菌数;4℃冷藏4周时,MG1-5、MG2-1、MG4-2和MG1-12的存活率分别为96.86%、90.39%、89.73%和89.39%,乳糖分解率分别为39.52%、58.2%、46.57%和40.22%;4株菌表现出不同的发酵特性,MG2-1有较强产酸能力、蛋白水解能力和乳糖分解能力（P＜0.05）,MG1-5则具有更高存活率,MG1-12表现出更强产粘能力.     

酸驼乳中益生乳酸菌的分离筛选

旨在评价酸驼乳中乳酸菌的益生特性。采用常规方法从内蒙古阿拉善牧区采集的酸驼乳中分离乳酸菌;利用16S r DNA PCR及序列分析法对分离到的乳酸菌进行种水平鉴定;通过体外抑菌试验和耐酸、耐胆盐试验评价乳酸菌的益生特性。结果表明,从酸驼乳中分离到的1株疑似乳酸菌被鉴定为短乳杆菌,将其命名为Lactobacillus breris LT;该菌株的代谢产物对4种常见肠道性致病菌(大肠杆菌、金黄色葡萄球菌、鼠伤寒沙门菌、单增李斯特菌)均表现出良好的抑菌特性,且抑菌特性不受胃蛋白酶和胰蛋白酶的影响;该菌株能够在低p H值(2.0、3.0)和高胆盐含量(0.1%~0.3%)的MRS培养基上生长。该研究结果为酸驼乳中优质乳酸菌资源的开发利用提供了科学依据。     

一株高产酸乳酸菌的分离、鉴定及高密度发酵研究

为获取产酸能力强、发酵性能好、具有强抑菌能力的乳酸菌,本试验以35日龄断奶健康仔猪粪便为菌源,对其乳酸菌进行筛选、分离、鉴定,并对分离菌株进行发酵性能研究。从35日龄断奶健康仔猪粪便中分离得到6株目标菌株,经产酸测试及抑菌试验后,得到一株产酸能力强、抑菌效果良好的筛选菌株,命名为RSJ-5。通过对RSJ-5菌株的菌落与菌体形态观察、生理生化鉴定试验、糖醇发酵试验,确定其为嗜酸乳杆菌。利用50 L发酵罐接种RSJ-5菌株厌氧发酵36 h,发酵液活菌数达158 CFU/mL,乳酸钙含量为85 mg/mL,pH4.2,发酵液对大肠杆菌、沙门氏菌有较强抑菌作用。结果表明RSJ-5嗜酸乳杆菌具备优良乳酸菌发酵剂的性能,探索了发酵工艺的可行性,为液体饲料(乳酸菌发酵液)大规模发酵生产提供参考。     

猪源生物膜乳酸菌的筛选与生物学特性分析

为了筛选能够用于养猪生产中的潜在益生乳酸菌,试验从健康猪粪便中筛选出乳酸菌,并采用16S rDNA分子生物学方法进行鉴定,然后进一步对该菌株进行体外生物学特性分析和小鼠致病性试验。结果表明:从猪粪便中共分离出3株疑似乳酸菌菌株,而后从3株疑似乳酸菌菌株中成功筛选出1株具有抗菌活性和生物被膜形成能力的乳酸菌,命名为L-18,并确定乳酸菌L-18株为约氏乳杆菌(Lactobacillus johnsonii)。L-18株乳酸菌具有产酸能力,能够耐受50℃和60℃、pH值2.0～10.0以及1%胰蛋白酶环境;对猪小肠上皮细胞的黏附率为77.04%,与鼠李糖乳杆菌ATCC53103相比差异显著(P0.05);在MRS液体培养基中培养大约4 h后进入对数生长期,并持续生长8 h后进入稳定期;对青霉素等8种药物高度敏感,对头孢他定等6种药物中度敏感,对庆大霉素等6种药物表现出耐药;小鼠致病性试验表明L-18株乳酸菌具有安全性,无毒性。说明L-18株乳酸菌具有益生菌的典型特性和功能,可用于开发和利用。     

家禽发酵饲料乳酸菌菌株的筛选

为了筛选出适宜家禽发酵饲料用的乳酸菌菌株,试验以散养鸡消化道内容物为样品,利用MRS培养基共分离出98株乳酸菌菌株,通过16S rRNA分子生物学鉴定和产酸性能测定,发现其中有8株候选菌株表现出了良好的产酸特性。进一步对8株候选菌株的益生特性测定发现,除FJ-11、FJ-52和FJ-66外,其余5株候选菌株均表现出良好的耐酸、耐胆盐特性,抑菌特性和细胞表面疏水性。因此,最终选择这5株备选菌株进行饲料发酵试验。结果表明:FJ-38(植物乳酸杆菌)和FJ-92菌株(唾液乳酸杆菌)发酵组经过72 h发酵乳酸含量大于100 mmol/L,乙酸含量小于40 mmol/L,最终p H值≤4.5。说明这2株候选菌株可以作为有效的发酵饲料所需菌株,但最终在生产中使用的安全性、大规模生产条件和低温发酵效果还有待进一步研究。     

自然发酵酸菜汁中乳酸菌的分离鉴定及抑菌活性的分析

为了检测乳酸菌的抑菌活性,试验从自然发酵酸菜汁中分离、纯化出10株乳酸菌,通过体外试验筛选出4株产酸力较强的乳酸菌,经生理和生化鉴定分别为植物乳杆菌、干酪乳杆菌、嗜酸乳杆菌和短乳杆菌。牛津杯抑菌试验结果表明:4株乳酸菌对大肠杆菌、铜绿假单胞菌、金黄色葡萄球菌均有明显的抑菌作用,而对肺炎克雷伯菌和白色念珠菌无效;产酸量大的菌株抑菌作用也强,推测其抑菌作用与低酸环境有关。说明研究和开发乳酸菌抑菌产品具有广阔前景。     

猪源嗜酸乳杆菌的分离鉴定及益生特性研究

为丰富猪源益生菌资源,研制品质更好及效果更强的猪用微生态制剂,研究从健康仔猪粪便中分离获得9个菌株,通过对菌株形态及生理生化特征得到2株疑似嗜酸乳杆菌菌株,分别命名为L102和L106,通过16S rDNA分析表明,菌株L102和L106均为嗜酸乳杆菌;并对2株菌的益生特性进行研究,结果表明,2株菌均有较强的抑菌能力,菌株L102对大肠杆菌、金黄色葡萄球菌和沙门菌的抑菌圈直径均超过22 mm,菌株L106的抑菌圈直径则超过15 mm。但2株菌对酸及胆盐的耐受性一般,用p H 3.0液体培养基处理2 h,菌株L102存活率为77.40%,菌株L106存活率为59.20%;胆盐质量分数为0.30%时,菌株L102存活率为28.20%,菌株L106存活率为18.70%。     

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。     

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。     

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。     

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。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

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.