基于复合益生菌和枯草芽孢杆菌发酵转化大豆异黄酮的比较研究北大核心

试验旨在通过利用枯草芽孢杆菌ATCC 6633和复合益生菌2株菌株单独及按不同比例混合后发酵豆粕的试验,采用高效液相色谱对发酵结束后大豆异黄酮（SIF）的含量进行检测发现,大豆苷、染料木苷、大豆苷元和染料木素在4~40 mg/L有着良好的线性关系,EM菌在发酵10 d后苷元的转化效率最高,苷元含量在SIF总量中的比率达54.18%。试验研究可为今后饲料发酵工业提供一定的理论基础。     

基于复合益生菌和枯草芽孢杆菌发酵转化大豆异黄酮的比较研究

试验旨在通过利用枯草芽孢杆菌ATCC 6633和复合益生菌2株菌株单独及按不同比例混合后发酵豆粕的试验,采用高效液相色谱对发酵结束后大豆异黄酮(SIF)的含量进行检测发现,大豆苷、染料木苷、大豆苷元和染料木素在4~40 mg/L有着良好的线性关系,EM菌在发酵10 d后苷元的转化效率最高,苷元含量在SIF总量中的比率达54.18%。试验研究可为今后饲料发酵工业提供一定的理论基础。     

产β-甘露聚糖酶菌株HTGC-10对豆粕抗营养因子改性的实时监测分析

试验旨在实时监测豆粕发酵过程中抗营养因子的降解效果。以β-甘露聚糖酶高产菌株HTGC-10为发酵菌株,降解甘露聚糖,使用薄层层析及实时电泳检测菌株HTGC-10的降解效果。结果显示,菌株HTGC-10可将甘露聚糖降解为小分子的甘露寡糖;使用HTGC-10发酵10%的豆粕,在发酵的0～24 h内,菌株HTGC-10可以很好地降解豆粕中的大分子蛋白。在发酵的0～24 h内,菌株HTGC-10可以很好地降解抗营养因子,将豆粕中的大豆球蛋白、β-伴大豆球蛋白和KTI抗营养因子分别降解至原含量的11.9%、18.5%和2.0%,继续发酵24～48 h对豆粕抗营养因子的降解作用不大。研究表明,豆粕发酵以24 h为宜,可以更好地利用豆粕资源。     

不同发酵方式处理对豆粕的影响

本研究分别选择米曲霉、芽孢杆菌及乳酸菌菌株进行豆粕固态发酵,以考察不同发酵方式对豆粕影响。试验结果表明,采用组合发酵方式处理的豆粕产物,其各项发酵指标均为最优,在大豆抗原蛋白去除效果方面,米曲霉与芽孢杆菌菌株的单菌种发酵均能起到较好的大豆抗原蛋白降解效果,乳酸菌降解效果较差。     

耐酸产蛋白酶芽孢杆菌菌株的筛选及其生料固体发酵豆粕效果评价

以酸性脱脂牛奶培养基为限制性培养基,结合透明圈法进行初筛,以酸性蛋白酶活力为指标进行复筛;通过菌落及菌体形态观察、生理生化特性测定、16S r DNA序列系统发育分析相结合的方法鉴定供试菌株种属;通过室温18℃下固体发酵豆粕试验,探索供试菌株降解大分子抗营养因子、提高酸溶蛋白相对含量的可行性,并以酸溶蛋白相对含量为指标,采用正交试验设计考察料水比、玉米粉含量、硫酸铵含量、菌株接种量4个因素,优化固体发酵豆粕的条件。试验共获得133株初筛菌株,以其中透明圈直径2.00 cm的菌株SD47、SD48、SD56和SD62进行复筛,筛选出SD48菌株,其酸性蛋白酶活力为75.40 U/ml。SD48菌株被鉴定为甲基营养型芽孢杆菌(Bacillus methylotrophicus)。SD48菌株固体发酵豆粕30 d时,发酵豆粕色泽金黄,具有浓郁酸香味,无结块现象;发酵豆粕p H值降低,酸溶蛋白相对含量和抗氧化活性提高,β-伴大豆球蛋白和大豆球蛋白接近完全降解。最优的发酵条件为:料水比11、玉米粉含量10.0%、硫酸铵含量6.0%、菌株接种量8.0%、发酵时间30 d。与基础发酵条件下发酵30 d的结果相比,在最优条件下,酸溶蛋白相对含量提高了127.6%,抗氧化活性提高了185.8%。SD48菌株耐受酸性环境,可在胞外产生蛋白酶,极大地提高发酵豆粕的营养价值,是一株性能优良的发酵豆粕用菌株。     

枯草芽孢杆菌固态发酵豆粕效果比较

以豆粕为主要原料,通过测定6株枯草芽孢杆菌固态发酵豆粕的粗蛋白、酸溶蛋白含量,并利用SDS-PAGE对发酵豆粕中的大豆抗原蛋白降解情况进行定性分析,比较枯草芽孢杆菌对豆粕的作用效果,筛选出发酵豆粕优势菌株。试验结果显示,与豆粕相比,6株枯草芽孢杆菌固态发酵豆粕48、72、120 h的粗蛋白和酸溶蛋白含量均有所提高,但提高的程度有所差异;菌株Y6发酵豆粕效果优于其他五株枯草芽孢杆菌,发酵120 h的粗蛋白提高了15.7%,酸溶蛋白含量可达9.85%,抗原完全降解。     

固态发酵生产豆粕多肽饲料的温度分段调控研究

试验研究温度分段控制对豆粕固态发酵生产豆粕多肽饲料的影响。选用普通饲料豆粕为原料,米曲霉作为发酵菌种,在对菌株生长性质和蛋白酶学性质研究的基础上,以豆粕蛋白水解度为测定指标,对影响菌株发酵豆粕制备大豆肽的温度因素进行了分段研究,并运用混料设计法对不同温度的不同时间段进行了优化预测及验证。结果表明:在用米曲霉固态发酵豆粕的过程中,通过温度分段控制,可以达到生产多肽饲料的目的(豆粕蛋白水解度10%以上),并得到了最优发酵条件:0～33.5 h、26℃;33.5～50 h、23℃;50～65 h、45℃,在此条件下,豆粕蛋白的水解度为19.5%。温度分段控制对固态发酵生产豆粕多肽饲料影响明显,可大幅度提高豆粕蛋白的水解度(比原有工艺提高了140%)。     

发酵豆粕对犊牛生长性能的影响

本文旨在研究发酵豆粕对犊牛生长性能的影响。选取16头健康荷斯坦犊牛,按照体重、出生日期相近原则随机分为试验组和对照组,每组各8头,分别饲喂发酵豆粕试验料和以膨化大豆为主要成分的牧场原有品牌犊牛料。结果显示,使用发酵豆粕能够使犊牛平均日增重提高0.1kg/头,饲料转化率提高0.04,降低配方成本3.60元/t。试验表明,发酵豆粕使用效果优于膨化大豆,能够提高犊牛生产性能、降低养殖投入和生产成本,能够在犊牛料中使用。     

微生物发酵法生产大豆肽工艺条件的研究

以脱脂豆粕为原料,采用地衣芽孢杆菌发酵生产大豆肽.研究菌株种龄、种子液接种量和摇床速度对多肽产量的影响,结果表明,种龄12 h,接种量5%,摇床速度180 r/min最佳.同时,对影响多肽产量的发酵温度、发酵时间及豆粕粉加水量3个主要因素用正交试验方法进行优化,正交试验结果发现,该菌株发酵产多肽的最佳条件为温度37℃,发酵时间48 h,加水量94%.优化后该菌株发酵豆粕后的多肽溶液酸性可溶氮含量达到1 384.65μg/mL,水解度DH为23.89%.     

雌马酚的产生、生物学功能及潜在应用

雌马酚(equol)是大豆异黄酮在动物肠道微生物菌群作用下的代谢产物之一,具有比大豆异黄酮更高的生物学活性。除了激素样作用外,雌马酚还具有抗氧化、免疫调控及保健功能,在畜禽上的研究表明其具有改善肉品质、缓解氧化应激的作用。本文主要从雌马酚的理化性质、产生与代谢、影响生成的因素、生物学功能及应用等方面来综述,旨在为雌马酚在畜禽上的科学应用提供思路。     

Dietary isoflavone absorption, excretion, and metabolism in captive cheetahs (Acinonyx jubatus)

Dietary isoflavones, capable of influencing reproductive parameters in domestic cats (Felis catus), have been detected in commercial diets fed to captive cheetahs (Acinonyx jubatus). However, the absorptive and metabolic capacity of cheetahs towards isoflavones has not yet been studied. Experiments were designed to describe the plasma concentration-time curve, metabolite profile, and urinary and fecal excretion of genistein and daidzein in cheetahs following consumption of isoflavones. Four adult cheetahs were administered a single oral bolus of genistein and daidzein, and five juvenile cheetahs consuming a milk replacer formula found to contain isoflavones were also included. Urine was collected from all animals, and blood and feces were also collected from adult cheetahs following isoflavone exposure. Samples were analyzed for isoflavone metabolite concentration by liquid chromatography-electrospray ionization-multiple reaction ion monitoring mass spectrometry and high-performance liquid chromatography. Sulfate conjugates were the primary metabolites detected of both genistein and daidzein (60-80% of total isoflavones present) in the plasma and urine of cheetahs. A smaller proportion of daidzein was detected as conjugates in the urine of juvenile cheetahs, compared to adult cheetahs. Other metabolites included unconjugated genistein and daidzein, O-desmethylangolensin, and dihydrodaidzein, but not equol. Only 33% of the ingested genistein dose, and 9% of daidzein, was detected in plasma from adult cheetahs. However, of the ingested dose, 67% of genistein and 45% of daidzein were detected in the feces of adults. This study revealed that cheetahs appear efficient in their conjugation of absorbed dietary isoflavones and only a small fraction of ingested dose is absorbed. However, the capacity of the cheetah to conjugate genistein and daidzein with sulfate moieties appears lower than reported in the domestic cat. This may confer greater opportunity for biologic activity of isoflavones in the cheetah than would be predicted from findings in the domestic cat. However, further investigation is required.     

Protective effect of the isoflavone equol against DNA damage induced by ultraviolet radiation to hairless mouse skin

Equol, an isoflavonoid metabolite produced from the dietary isoflavone daidzein by the gut microflora in mammals, has been found to protect not only against ultraviolet (UV) radiation-induced cutaneous inflammation and photoimmune suppression, but also have anti-photocarcinogenic properties in mice. Because the state of DNA damage has been correlated with suppression of the immune system and photocarcinogenesis, we have therefore examined the potential of equol to offer protection from solar-simulated UV (SSUV) radiation-induced DNA damage in hairless mice by the immunohistochemical approach using monoclonal antibody specific for cyclobutane pyrimidine dimers (CPDs; H3 antibody). Topical application of 20 µM equol lotion, which was applied both before and after SSUV significantly reduced the number of CPDs. This reduction was evident immediately after SSUV exposure, at 1 h after exposure, and at 24 h after exposure, revealing 54%, 50%, and 26% reduction in CPDs, respectively. When the same concentration was applied for 5 consecutive days after SSUV exposure, there was no significant difference in the reduction of CPDs immediately after SSUV irradiation or at 1 hour afterwards, but there were significant reductions of 23% and 42% at 24 and 48 h after SSUV exposure, respectively. Despite apparently reducing the number of CPDs post-SSUV, topically applied equol did not appear to increase the rate of dimer removal. To conclude, equol applied topically prior to SSUV irradiation offers protection against CPD formation in hairless mice, possibly by acting as a suncreen and thus inhibiting DNA photodamage.     

Concentrations of isoflavones and their metabolites in the blood of pregnant and non-pregnant heifers fed soy bean

The present study compared the changes in isoflavones (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cyclic and pregnant heifers after feeding with soy bean. Twelve healthy heifers were divided into three groups: cyclic heifers (days 8-12 of the estrous cycle; control group; n=4), an early pregnancy group (2 months pregnant; n=4) and a late pregnancy group (8 months pregnant; n=4). All heifers were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on an HPLC system. In the blood plasma of the early- and late-pregnant heifers, we found lower concentrations and time-dependent decreases in daidzein and genistein in comparison to cyclic heifers (P<0.05). Moreover, we noticed significant increases of equol and para-ethyl-phenol in the blood plasma of the early-pregnant heifers (P<0.05). In contrast, in the blood plasma of the late-pregnant heifers, we did not find an increase in the isoflavone metabolite concentrations compared with the early-pregnant heifers (P>0.05). In conclusion, physiological status (cyclicity or pregnancy) of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the heifers. The stage of pregnancy affects isoflavone absorption, biotransformation and metabolism differently and results in higher concentrations of active metabolites of isoflavones during early pregnancy in comparison to their lower concentrations during late pregnancy. Therefore, we surmise that cows are more sensitive to active isoflavone metabolite actions during early pregnancy than cyclic heifers and heifers in late pregnancy.     

米曲霉发酵豆粕营养特性的研究

通过米曲霉对豆粕进行发酵,对发酵后豆粕的常规营养组成,粗蛋白质的组成、蛋白质的营养特性进行了分析,并将分析结果校正至发酵前的底物含量,探讨微生物发酵对豆粕中各营养组分的改造程度。结果表明:经检测,与未发酵豆粕相比,发酵豆粕中粗蛋白含量无显著变化,但其组成发生了改变,真蛋白质降低了19.19%(P<0.05),生成了2.02%的微生物蛋白,非蛋白氮水平增加了369.08%(P<0.05);发酵豆粕中大分子蛋白(>60 ku)和中分子蛋白(30～60 ku)被降解为小分子蛋白(<30 ku),有效消除了大豆抗原和抗营养因子。同时,发酵使豆粕中NDF、ADF和NFE的含量分别显著降低了16.77%(P<0.05)、12.57%(P<0.05)、22.25%(P<0.05),粗脂肪含量增加了179.25%;但豆粕发酵后底物重量、蛋白质和总能分别损失了5.14%、3.06%和3.86%。这表明米曲霉发酵过程中以损耗一部分碳水化合物和蛋白质作为代价,使豆粕本身蛋白质发生了一定程度的分解,从而获得了一种饲用特性更高的蛋白饲料。     

发酵豆粕在断奶仔猪浓缩料中的应用研究

试验选择（35±2）日龄断奶仔猪120头,随机分为3个处理,每个处理5个重复,每个重复8头猪,进行为期21 d的饲养试验,研究两种发酵豆粕在断奶仔猪浓缩料中应用效果。结果表明,在断奶仔猪浓缩料中添加发酵豆粕能改善仔猪的生长性能,且不同的发酵豆粕应用效果不同。从试验全期来看,发酵豆粕试验组的日增重、日采食量、料重比均好于43豆粕对照组,但均差异不显著（P〉0.05）。试验Ⅱ组仔猪的生长性能表现最好。从试验结果来看,试验Ⅱ组效果最好,试验Ⅰ组次之,试验Ⅱ组仔猪日增重较试验Ⅰ组、对照组分别高8.26%、8.92%;试验Ⅱ组日采食量较试验Ⅰ组、对照组分别高4.32%、5.16%;试验Ⅱ组料重比较试验Ⅰ组、对照组低3.92%、4.32%。     

发酵杂粕型饲粮添加小肽对肉牛生长性能、养分表观消化率及血清生化指标的影响

本试验旨在研究发酵杂粕型饲粮中添加小肽对肉牛生长性能、养分表观消化率及血清生化指标的影响,探索发酵杂粕型饲粮中小肽适宜的添加水平.试验选取初重为(481.43±36.36)kg、健康状况良好的肉牛28头,随机分为4组,每组7头牛,分别饲喂小肽添加水平为0(Ⅰ组)、0.5％(Ⅱ组)、1.0％(Ⅲ组)和1.5％(Ⅳ组)的全...     

Composition of some urinary calculi of ruminants in Western Australia.

Forty ruminant urinary calculi, selected as being essentially inorganic and mainly obtained from sheep grazing in the drier wheatbelt areas of Western Australia, were examined by optical and X-ray diffraction techniques. Four mineral types-silica (SiO2-nH2O), weddellite (CaC2O4-2H2O), calcite (CaCO3) and aragonite (CaCO3)--were found. These minerals were present respectively in 30, 17, 13 and 1 of the 40 calculi examined and were the sole component in 12, 0, 7, and 0 calculi. One calculus was found to be composed of organic material which was subsequently shown to consist mainly of 4'-O methyl equol (4'-methoxy-7-isoflavanol, C16H16O3) with a small amount of equol and a trace of formononetin. This is the first report of a calculus of this composition. Determinative data useful for identification of 4'o-methyl equol, equol and a related substance are presented in an appendix.     

Gastric emptying of glucose in the dog

The 30-minute gastric emptying of test meals consisting of 2.5%, 4%, 7%, 15%, or 25% glucose was evaluated in healthy, nonoperated dogs, using an orogastric intubation technique. An inversely proportional exponential relationship was found between test meal glucose concentration and amount of test meal emptied from the stomach in 30 minutes. For the 7%, 15%, and 25% glucose test meals, a mean (+/- SEM) of 1.11 +/- 0.03 kcal/min emptied into the duodenum, which represented 0.054 +/- 0.004 kcal/min/kg of body weight. Test meals of 2.5% and 4% glucose supplied significantly fewer kcal per minute to the duodenum than did the other 3 meals, indicating that control of gastric emptying of hypotonic glucose meals may be different than that of isotonic or hypertonic test meals in the dog.     

Effects of fungal (Aspergillus niger or Ceriporiopsis subvermispora) fermentation on the nutritive value of shea nut (Vitellaria paradoxa) meal for broiler chicks

1. Shea nut (Vitellaria paradoxa Gaertn.) meal was fermented for 8 d with either Aspergillus niger, Ceriporiopsis subvermispora or a mixture of the two organisms. The fermentation was completed using two methods, an opened container or a closed container. 2. Each of the 6 samples was dried and incorporated into basal broiler diets at 90 g/kg. 3. In addition, the unfermented shea nut meal was incorporated in the diet at 90 g/kg and the basal diet (maize and soybean meal based) was also provided as an eighth dietary treatment to individually caged broiler chickens. 4. All fermented fungi-treated shea nut meals had similar proximate nutrient compositions to the unfermented shea nut meal, but there were substantial decreases in their hydrolysable tannins and saponin contents. Both fermentation methods gave similar reductions in the concentrations of tannins and saponins. 5. Shea nut meal fermented with individual or both fungal organisms gave greater (P < 0.001) growth performance than that of unfermented shea nut meal. However, all shea nut meals including the unfermented meal gave lower (P < 0.001) growth variables than those for the maize-soybean meal control. 6. The nutritional improvement of shea nut meal achieved in this study still falls far short of what is expected for it to become valuable for the poultry feed industry. These fermentation methods using A. niger or C. subvermispora require further improvements to provide satisfactory feed products.     

大豆黄酮、芒柄花素及其组合对奶牛产奶性能、血浆和乳中激素含量的影响

本试验旨在研究大豆黄酮、芒柄花素及其组合对奶牛产奶性能、血浆和乳中激素含量的影响。选取健康年龄、泌乳期相近的40头荷斯坦奶牛,随机分为4组,分别为对照、Ⅰ、Ⅱ、Ⅲ组,每组10头。所有奶牛饲喂全混合日粮,试验Ⅰ、Ⅱ、Ⅲ组在此基础上分别添加2.50 g大豆黄酮、35.0 g芒柄花素、1.25 g大豆黄酮+17.5 g芒柄花素。进行127 d的饲养试验,其中预试期7 d,正试期120 d。结果显示:试验Ⅰ、Ⅱ、Ⅲ组产奶量与对照组相比差异显著(P0.05),分别比对照组提高了30.40%、27.77%、28.37%;试验组的乳脂产量均高于对照组,但差异不显著(P0.05);试验组的乳蛋白率和乳蛋白产量均高于对照组,其中试验Ⅲ组与对照组相比差异显著(P0.05);试验Ⅰ、Ⅱ、Ⅲ组乳糖产量显著高于对照组(P0.05);对照组乳尿素氮含量显著高于试验Ⅱ组(P0.05);试验组血浆中雌酮含量低于对照组,而试验组乳中雌酮含量高于对照组,但差异均不显著(P0.05);试验组血浆和乳中雌二醇-17β含量均高于对照组,试验Ⅲ组与对照组差异显著(P0.05);试验组血浆和乳中孕酮含量均高于对照组,其中血浆中试验Ⅱ组与对照组差异显著(P0.05),乳中试验Ⅰ、Ⅲ组与对照组差异显著(P0.05);各组间血浆中促卵泡素、促黄体素含量差异不显著(P0.05);各试验组血浆中催乳素含量均高于对照组,其中试验Ⅱ组与对照组差异显著(P0.05);试验组乳中雌马酚含量显著高于对照组(P0.05)。因此,补饲大豆黄酮、芒柄花素及其组合可提高奶牛产奶量,改善乳品质,显著增加乳中雌马酚含量,同时使奶牛血浆和乳中雌二酮、孕酮含量增加。