不同工艺对益生菌发酵饲料感观、pH值与重量损耗的影响

试验用植物乳酸菌对饲料原料进行了液态转固态发酵工艺和液态发酵、固态发酵工艺的比较研究。结果表明,液态转固态发酵工艺组发酵饲料能较好的保持饲料的色泽,气味香甜,7d内没出现霉变;乳酸含量略低于液态发酵工艺组,pH值变化规律与乳酸含量基本一致;发酵损耗远低于固态发酵工艺组。     

不同发酵温度对液体发酵饲料营养成分、挥发性脂肪酸和活菌数的影响

文章旨在研究不同发酵温度对液体发酵饲料营养成分、挥发性脂肪酸和活菌数的影响。试验分别设定20、25、30℃三个发酵温度，每个发酵温度设置6个重复，厌氧发酵24?h。试验结果表明，随着发酵温度的升高，饲料中粗蛋白质含量显著提高（P <0.05），粗纤维含量无显著变化（P> 0.05），但总能显著降低（P <0.05）;25和30℃发酵时，液体饲料中乳酸含量显著高于20℃组（P <0.05），但25和30℃之间差异不显著（P> 0.05）；而挥发性脂肪酸方面，25和30℃发酵时，饲料中乙酸和丙酸含量显著高于20℃发酵组（P <0.05），而25和30℃之间的丙酸含量差异不显著（P> 0.05），乙酸含量25℃发酵组高于30℃发酵组（P <0.05）。丁酸含量则随发酵温度升高而显著降低（P <0.05）；液体饲料中的乳酸菌和酵母菌活菌数显著升高（P <0.05），其中25和30℃发酵组酵母菌活菌数无显著差异（P> 0.05）；液体饲料中均未检出沙门氏菌和大肠杆菌。     

酿酒酵母菌固态发酵工艺研究

研究在单因素优化试验的基础上,采用正交试验对酿酒酵母菌固态发酵工艺进行研究,主要包括发酵时间、接种量、料水比、碳源、氮源和无机盐等因素,最终确定酿酒酵母菌的固态发酵工艺。发酵条件:自然pH条件下,发酵温度30℃、发酵时间72 h、接种量7.00%及料水比1∶1.25。培养基成分:麸皮与甘油比9∶1、尿素0.50%及磷酸二氢钾0.20%。依照此工艺进行发酵,酿酒酵母菌活菌数最高可达8.60×1亿/g个。     

固态热带假丝酵母菌菌剂的发酵工艺研究

试验在单因素优化试验的基础上,采用正交试验进一步对热带假丝酵母菌固态发酵工艺进行研究,包括发酵时间、接种量、料水比、碳源、氮源、无机盐等因素,最终确定热带假丝酵母菌的固态发酵工艺。发酵条件:在自然pH值条件下,发酵温度30℃、发酵时间48 h、接种量11%、料水比1∶0.75。培养基成分:麸皮与甘油8.5∶1.5 (g/g)、尿素0.5%、磷酸二氢钾0。依照此工艺进行发酵,热带假丝酵母菌活菌数最高可达32.94×10⁸个/g。     

产大豆肽蛋白饲料的研制及其固态发酵工艺参数的优化研究

就2种菌组合协同固态发酵生产功能大豆寡肽蛋白饲料工艺参数优化的工业化研究结果进行了总结。其模式为:2种菌组合→液态接种→发酵池封闭式发酵。筛选菌种:枯草芽胞杆菌和乳酸杆菌。经优化后发酵工艺参数:时间38h;pH值为7～8;初始培养温度(37±1)℃;芽胞杆菌菌液接种量2%,乳酸菌接种量为3%;料水比为2∶1;底物组成:豆粕90%、麸皮7%、玉米粉3%。     

功能大豆寡肽蛋白饲料的研制及其固态发酵工艺参数的优化研究

本文就多菌种组合协同固态发酵生产功能大豆寡肽蛋白饲料工艺参数优化的工业化研究结果进行了总结。固态开放式生产功能大豆寡肽蛋白饲料的模式为:多菌种组合→液态接种→深层(≥10cm)、堆式、开放式发酵。经筛选的复合菌系为:乳酸菌、枯草芽孢杆菌、粪链球菌、黑曲霉与酵母菌。经优化的发酵工艺参数为:时间48h;pH值为6.0~8.0;24h前温度30±1℃,24h后温度28±1℃;菌液接种量5%(v/w);料水比1∶0.7;底物组成:豆粕70%、麸皮27%、玉米粉3%。并就影响因素中最为关键的菌种因素与烘干条件进行了详细讨论。     

枯草芽孢杆菌发酵菌糠制备饲料微生物添加剂的研究

试验旨在优化枯草芽孢杆菌发酵金针菇菌糠的条件进而制备饲料微生物添加剂。试验采用L1(645)正交试验,测定枯草芽孢杆菌发酵金针菇菌糠的培养温度(A)、外源氮水平(B)、初始pH值(C)、发酵时间(D)、菌液接种量(E)5个因素对芽孢数的影响,同时测定发酵产物的有毒、有害物质含量。结果表明,枯草芽孢杆菌的最适发酵条件为培养温度35℃、棉粕添加量3%、初始pH值7.5、发酵时间48 h、菌液接种量10%。对其发酵结果的影响程度依次是外源氮水平>初始pH值>发酵时间>接种量>培养温度。此添加剂中的黄曲霉毒素B1以及重金属砷、铅、汞、镉的含量均符合国家饲料添加剂卫生指标。在此条件下固态发酵菌糠,枯草芽孢杆菌的芽孢数为8×109cfu/g(干重),对其发酵后产品烘干即得到饲料微生物添加剂。     

金针菇菌渣发酵饲料制作的工艺优化

旨在用含植物乳杆菌、枯草芽孢杆菌和酿酒酵母的复合菌制剂发酵金针菇菌渣饲料,提高金针菇资源的利用率。利用正交试验,研究复合菌剂的接种比例、接种量、水分、发酵温度和发酵时间等因素对发酵金针菇菌渣饲料的pH值和乳酸、氨态氮、还原糖、挥发性脂肪酸等指标含量的影响;在此基础上,筛选出复合菌固态发酵金针菇菌渣的最优工艺。结果显示,最优发酵参数为:植物乳杆菌、枯草芽孢杆菌、酿酒酵母菌接种比例2∶2∶1,接种量5%,固体培养基含水量50%,温度33℃,发酵时间5 d。与发酵前相比,发酵后金针菇菌渣的粗蛋白含量显著提高(P0.05),pH值显著下降(P0.05)。研究表明:以植物乳杆菌、酿酒酵母菌和枯草芽孢杆菌复合菌发酵金针菇菌渣饲料后,菌渣pH值降低,且营养成分得到改善。     

拮抗草坪蘑菇圈生防菌剂的关键发酵工艺及优化

为获得草坪蘑菇圈病原菌拮抗生防菌剂的优化参数,本研究以拮抗蘑菇圈病原-肉褐麟小伞菌(Lepiota brunneo-incarnata)的黄曲霉(Aspergillus flavus)CP01为目的菌,对其分别进行液、固态发酵条件的优化。通过单因素试验优化发酵时间、培养温度、培养基类型及初始pH等条件,对最佳液态发酵条件进行筛选;并通过单因素试验优化培养物料、外源养分、发酵时间和温度等条件,对最佳固态发酵条件进行筛选。结果表明:液体发酵条件下,马铃薯葡萄糖液体培养基(PDB)中菌丝体干重含量最高,而在青秸秆粉浸提液培养基(CSE)中有效菌数最高,且该发酵液对蘑菇圈病原的抑菌效果最佳,培养基最适初始pH为5、最佳发酵条件为30℃、5d;在固态发酵条件下,最适发酵培养物料为经浸提法去营养化的青秸秆粉,外源添加养分为料水比1∶50的青秸秆粉浸提液,最适发酵条件为33℃、9d。以上优化参数为草坪蘑菇圈生防菌剂的研发奠定了基础。     

拮抗产肠毒素大肠杆菌K88的中药和益生菌的筛选及其发酵工艺优化

目的:筛选对产肠毒素大肠杆菌(ETEC)K88具有较好抑菌效果的中药和益生菌,以发酵前后pH值变化和活菌数变化为指标,摸索益生菌发酵中药的影响因素,确定其最佳发酵工艺,并考察发酵液抑菌活性。方法:采用牛津杯法从20味中药和8株乳酸菌中筛选抑菌性能较好的中药和益生菌;通过单因素试验方法确定其最佳发酵工艺;采用牛津杯法检测发酵液抑菌活性。结果:6味单味中药和2株益生菌对K88具有较好的抑菌效果。益生菌发酵中药的最佳发酵工艺为:乌梅、蒲公英及五倍子按比例配制,接入4%的乳酸菌种子液,初始发酵pH值为5.5,37℃发酵24 h,发酵液抑菌效果优于乳酸菌菌液和中药水提液。结论:所筛选的中药组方配比及发酵工艺为开发防治产肠毒素大肠杆菌K88所致仔猪腹泻生物制剂提供了参考。     

Hematological changes in calves exposed to a mixture of lipopolysaccharide and crude leukotoxin of Pasteurella haemolytica.

The purpose of this investigation was to determine if culture supernatants of Pasteurella haemolytica containing crude leukotoxin and lipopolysaccharide (CLCL) causes disseminated intravascular coagulopathy (DIC) when injected into calves. The effect of intraduodenal (ID) exposure followed by a subsequent subcutaneous (SC) inoculation of either heat-treated or untreated CLCL was evaluated. The relative contribution of the crude leukotoxin and lipopolysaccharide (LPS) to the virulence of P. haemolytica was evaluated. One group of calves received an ID inoculation of CLCL followed two weeks later by a SC inoculation of CLCL; one group received an ID inoculation of tissue culture medium followed two weeks later by a SC inoculation of CLCL; and a third group received an ID inoculation of CLCL followed two weeks later by a SC inoculation of heat-treated CLCL. Hematological parameters used to evaluate DIC included white cell count, platelet count, neutrophil number, fibrinogen, fibrin degradation products, one stage prothrombin time (OSPT), activated partial thromboplastin time, body temperature and clinical signs. Each parameter was measured in calves at 0, 2, 4, 6, 12 and 24 h following the SC inoculation of CLCL. Each group had significant changes over time in all parameters except body temperature. Calves that received a SC inoculation of heat-treated CLCL had smaller changes in all parameters except OSPT compared to the other groups. Results suggest that the LPS and leukotoxin of P. haemolytica exert additive effects on the coagulation cascade and number of peripheral leukocytes, and that the ID inoculation of CLCL does not affect the response of calves to a SC inoculation of toxin.     

外加酶提高发酵豆粕蛋白质水解度的研究

在枯草芽孢杆菌发酵豆粕的工艺基础上添加外源蛋白酶进行优化,以蛋白质水解度为指标,试验得到酶添加量、接种量、料水比、温度、时间5个单因素的最佳条件为:加酶量120U/g,接种量1%、料水比1:1.2、温度35℃、发酵时间48h。对5个因素进行正交优化试验,得到优化发酵方案为:加酶量50U/g、接种量1.5%、料水比1:1.2、温度35℃、发酵时间48h,发酵豆粕水解度从对照的16.25%提高到37.29%,提高了1.3倍。     

Comparison of uterine protein content and distribution of bacteria in the reproductive tract of mares after intrauterine inoculation of Haemophilus equigenitalis or Pseudomonas aeruginosa

Two groups of 3 mares were inoculated with Haemophilus equigenitalis or Pseudomonas aeruginosa on the 1st day of estrus. Uterine flushing samples were recovered on day 3 of estrus and day 8 after ovulation for each cycle. Mares were killed 22, 25, and 30 days after inoculation with P aeruginosa and 45, 46, and 49 days after inoculation with H equigenitalis. Pseudomonas aeruginosa was recovered from the uterus of 2 mares 48 hours after inoculation. Although the initial flushing sample of 1 of these 2 mares had an increased total protein concentration, there appeared to be little difference between protein concentrations of other uterine flushing samples. Haemophilus equigenitalis was recovered from the uterus of each of the 3 mares at postmortem. One mare had a slight, purulent discharge from the vulva. Total protein values were not increased in flushing samples from this mare after inoculation with H equigenitalis. Total protein values decreased in the last flushing sample of each of the 2 remaining mares. Swabbing the uterus was more effective than was homogenizing the uterine mucosa in isolating H equigenitalis.     

Clinical and pathologic studies of experimentally induced Pasteurella haemolytica pneumonia in calves

Pasteurella haemolytica pneumonia of the right caudal lung lobe was experimentally induced in 2-week-old Holstein calves (n = 11) by endobronchial inoculation of 7.9 x 10(10) colony-forming units of 6-hour log-phase bacteria. Calves were studied for 72 hours after inoculation. The challenge procedure consistently induced a lesion in the right caudal lung lobe, which was consistent radiographically with results of pathologic examination and a similar volume of bronchography contrast medium. Clinically, the calves developed a significant increase in rectal temperature within 24 hours after inoculation. Seventy-two hours after inoculation, the total WBC counts, absolute band neutrophil counts, monocyte counts, and blood fibrinogen concentrations were significantly higher than normal and albumin concentration was significantly decreased. Necropsy revealed a circular to oblong lesion that was congested, edematous, and firm and occupied 20 to 40% of the right caudal lung lobe. Histologic examination revealed a severe acute inflammatory reaction characterized by cellular exudate and proteinaceous fluid in the alveoli, interlobular septa, and pleura.     

Effect of genistein on replication of bovine herpesvirus type 1

OBJECTIVE: To study the antiviral activity of genistein, a soya isoflavone, on in vitro replication of bovine herpesvirus type 1 (BHV-1). SAMPLE POPULATION: Madin-Darby bovine kidney (MDBK) cells. PROCEDURE: Effects of genistein on the magnitude and kinetics of inhibition of BHV-1 phosphorylation of glycoprotein E (gE) and in vitro replication of BHV-1 in MDBK cells were evaluated. Antiviral activity of genistein was compared with 2 compounds, estradiol-17beta (EST) and tamoxifen (TAM), that have estrogenic and antiestrogenic activity, respectively. High-performance liquid chromatography (HPLC) was used to determine the concentration of genistein in medium from infected and uninfected MDBK cultures. RESULTS: Genistein reduced BHV-1, but not gE-deleted BHV-1 (BHV-1gEdelta3.1), replication by 90% at 18 hours after inoculation. This inhibition was not sustained through 24 hours after inoculation. The genistein concentration in media from MDBK cells was decreased by 40% during BHV-1 infection, compared with 16% for uninfected cells, at 24 hours after inoculation. Genistein inhibited gE phosphorylation and BHV-1 replication in a dose-dependent manner. Dosing with 25 microM genistein at 0 and 12 hours after inoculation of BHV-1 was optimal for decreasing BHV-1 replication. Estradiol-17beta EST and TAM did not affect BHV-1 replication. CONCLUSIONS AND CLINICAL RELEVANCE: The decrease in genistein concentration was a viral infection-dependent event. Genistein is an inhibitor of BHV-1 replication because of its ability to inhibit tyrosine kinase activity. A possible application may be for the control of BHV-1 infection in cattle by feeding soya products rich in genistein prior to or during periods of stress.     

BHK-21细胞稳定测定猪乙型脑炎病毒半数细胞感染量效价（TCID_（50））的条件优化及应用

为建立BHK-21细胞测定乙型脑炎病毒（Japenese encephalitis virus,JEV）病毒效价的方法,对96孔细胞板中不同初始接种量BHK-21细胞在多种维持液中的生长状态进行探讨,发现当BHK-21细胞以1250～2500个/孔接种96孔板培养24 h后,更换含3%新生牛血清的DMEM后在37℃、5%CO2条件下可至少良好维持72～96 h。在此条件下并基于Reed-Muench法测定病毒效价的原理,本文建立了准确测定JEV TCID50的方法,利用该方法对JEV野毒分离株及商品疫苗进行测定,均获得稳定、准确的病毒效价。本实验为JEV的体外培养、病毒定量、疫苗评价等提供了一种准确、稳定、易判定的参考方法。     

一株产耐热纤维素酶放线菌的固体发酵研究

以一株产耐热纤维素酶放线菌为材料,研究了该菌固体发酵培养基组分的改良及固体发酵工艺的优化,同时探讨了该菌与酵母混菌发酵时的产酶情况。实验结果表明,该菌株的最适培养基成分为:稻草粉与麸皮比为1、豆粕30%、KH2PO41%、MgSO4·7H2O0.2%。最佳的发酵工艺条件为:培养基的初始pH值为7、发酵温度为35℃、培养基固与水体积比为0.8、菌株接种量为5%。该菌固体产酶发酵过程中第72h接入酵母菌的效果较好,酵母菌最佳接种量为1%,浓度为4.6×105cfu/ml。     

混合菌种发酵苹果渣生产蛋白饲料的工艺参数优化研究

本试验旨在研究2种不同菌剂（枯草芽孢杆菌和啤酒酵母）接种苹果渣原料进行微生物发酵的效果,并对混合菌种发酵结果的影响条件进行分析比较。通过3因素（浆料比、接种量、pH）正交试验设计,测定发酵产物中真蛋白质含量。结果表明,枯草芽孢杆菌和啤酒酵母混合菌种最佳发酵条件下真蛋白质含量最高,可达到13.58%,混合菌种发酵对产物中真蛋白质含量影响最大的因素是浆料比,其次是pH,推荐发酵参数为浆料比1.0∶1、枯草芽孢杆菌接种量3%、pH 5。酵母与菌剂之间呈协同作用可进一步提高发酵苹果渣中真蛋白质含量。     

以玉米粉和麸皮为主要原料生产单细胞蛋白饲料的研究

采用单因素实验设计,对酵母菌发酵,以玉米粉和麸皮为主要培养基原料的固体发酵培养基配方进行了筛选。以接种量、料水比例、发酵温度、发酵周期等因素作为研究对象,确定了最佳发酵条件。结果表明：筛选出的培养基配方为：玉米粉75%,麸皮21%,NH₄NO₃ 2%,KH₂PO₄ 1%,MgSO₄ 1%。适宜的发酵条件为：接种量12%,料水比例1∶1.5,发酵温度30 ℃,发酵周期66 h,该条件下发酵终产物粗蛋白含量最高,为20.56%。     

Measurement of total volume and protein concentration of intrauterine secretion after intrauterine inoculation of bacteria in mares that were either resistant or susceptible to chronic uterine infection.

Undiluted uterine secretion was used to determine the concentration of total protein and the accumulated volume of uterine secretion after a bacterial inoculation in mares susceptible and resistant to chronic uterine infection (CUI). The uterus of 6 susceptible and 5 resistant mares was inoculated with 5 x 10(6) Streptococcus zooepidemicus on the third day of estrus. Using a tampon inserted in the uterus, secretions were sampled at 5, 12, 24, and 36 hours after inoculation, followed by intrauterine lavage with phosphate buffered saline solution. The concentration of protein was determined in the undiluted secretion as well as in the uterine washing and the total amount of accumulated uterine secretion was calculated. Protein concentrations in plasma were compared before and after absorption by the tampon. Protein concentration of plasma before and after absorption by the tampon did not differ. Mares susceptible to CUI accumulated significantly (P less than 0.001) more fluid in the uterus than mares resistant to CUI, and uterine washings from the resistant mares were significantly (P less than 0.05) more dilute than those from the susceptible mares. Significant differences in protein concentrations between susceptible and resistant mares were not found. It was concluded from this study that the described method to sample undiluted uterine secretion was practical and reliable for the analysis of protein concentration. Various concentrations of uterine secretions in washings from susceptible and resistant mares emphasizes the importance in using undiluted uterine secretions or dilution markers in washings when intrauterine products are analyzed.