以白酒糟为基质进行酵母培养物的研究

为降低酵母培养物的生产成本,并实现白酒糟的资源化无污染化利用,试验以廉价的白酒糟为主要基质,接种酿酒酵母,进行酵母高密度固体发酵后,在此固体基质上进行酵母自溶处理,摸索酵母在白酒糟固体培养基中增殖后的最佳自溶条件,最终确定了在实验室条件下以白酒糟为基质生产酵母培养物的工艺条件:调整经酵母高密度发酵的固体酒糟基质初始p H值为6,向其中添加助溶剂:6%(w/w湿糟)的Na Cl溶液,0.04%(w/w湿糟)木瓜蛋白酶溶液以及9%(v/w湿糟)体积分数为95%的助溶剂无水乙醇,控制助溶剂添加总体积与酒糟干基总质量的体积质量比为1??1,搅拌分散,保持55℃自溶36 h,而后烘干粉碎制得成品。酵母高密度发酵后的白酒糟经自溶处理后产品氨态氮含量达到3.83 mg/g干糟。     

利用糖糟与啤酒糟生产蛋白饲料的研究

以糖糟和啤酒糟为原料,接入酵母菌,生产蛋白饲料。实验结果表明:在糖糟70%、啤酒糟30%的配比条件下,固态法发酵60h,发酵温度30℃,每克发酵基质中可得酵母95亿个。发酵基质粗蛋白从25%提高到36%,得到粗蛋白含量很高的优质蛋白饲料。     

基于大曲白酒糟固态发酵生产新型微生态功能饲料添加剂的研究

通过对产品的营养特征进行分析,以及对肉牛和肉羊的饲喂试验研究,旨在讨论以大曲白酒糟为基质进行固态发酵生产新型微生态功能饲料添加剂。结果显示:白酒糟酵母培养物各项理化指标均符合国家标准,尤其是蛋白质含量较高;不饱和脂肪酸含量占总脂肪酸含量的78%以上;含有16种氨基酸,谷氨酸含量占氨基酸总量的28.64%,且组成较为均衡;酵母活细胞数达到2亿个以上(以每克干酒糟计),且细胞自溶率达到90%以上;以30%白酒糟酵母培养物替代部分精补料添加到TMR中,可提高肉牛体重达28.6%;以一定比例添加到肉羊的精料中,亦可增加肉羊的体重达24.90%,并能明显改善肉羊的健康状况。     

复合菌固态生物转化啤酒糟发酵条件优化的研究

利用黑曲霉、绿色木霉、热带假丝酵母三菌株对啤酒酿造下脚料———啤酒糟进行固态发酵转化,在优化的培养基基础上,通过单菌种发酵试验,对发酵接种量、培养方式、菌种配比等进行优化;确定最佳的固态生物转化啤酒糟的发酵条件:菌种配比为,黑曲霉∶绿色木霉∶酵母=2∶1∶1,接种方式为先接黑曲霉、绿色木霉,24h后接酵母。经29℃,200r/min发酵5d得到的产品,具有多种酶活性,酸性蛋白酶酶活力达3540U/g(干基)、纤维素酶活力达432U/g(干基)、糖化酶活力达190U/g(干基),真蛋白质含量升高11.8%。     

饲用硒酵母制备工艺条件的优化

以啤酒酵母为菌种、添加亚硒酸钠的麦芽汁为培养基。从发酵液中硒浓度、发酵培养时间和接种量等方面研究了硒酵母发酵制备的效果。通过正交试验确定的最优工艺条件是:①发酵温度28℃;②接种量10%;③发酵培养基中的硒浓度25μg/ml;④发酵培养时间30h。经测定成品酵母的硒含量可达650mg/kg左右。     

固态发酵魔芋飞粉生产酵母蛋白饲料的研究

对魔芋飞粉固态发酵生产酵母蛋白饲料进行研究。单因素试验和正交试验优化的固态发酵培养条件:豆粕添加量为20%,葡萄糖淀粉酶添加量为0.3%,培养基含水量为50%,装料量为30g,接种量为1.5%,发酵温度为25℃,发酵时间为60h。优化后的发酵产品中酵母数可达到61.43亿/g,粗蛋白质含量可达34.02%,天门冬氨酸和苏氨酸等16种氨基酸含量均明显增加。在此基础上进行浅盘扩大培养,发酵产品中酵母数可达到60.10亿/g,粗蛋白质含量可达33.77%。     

混菌固态发酵清香型白酒糟制备蛋白饲料的研究

研究以清香型白酒糟为原料,添加酿酒酵母SY、枯草芽孢杆菌D和植物乳杆菌2-41进行混菌固态发酵,制备蛋白饲料。探索麸皮添加量对混菌固态发酵饲料质量的影响,优化发酵培养基配比后,采用单因素试验和正交试验,以酒糟饲料的粗蛋白含量为考察指标,研究发酵温度、发酵时间、菌种接种量和发酵培养基初始酸度对混菌固态发酵饲料质量的影响,从而优化混菌固态发酵工艺条件。结果显示,清香型白酒糟发酵培养基的最佳酒糟和麸皮比为9∶1,在酒糟初始水分为50%～60%的条件下,发酵培养基总装料量为50 g,其中清香型白酒糟45 g,麸皮5 g。混菌固态发酵最优工艺条件为菌种接种量13%、发酵温度26℃、发酵时间6 d、初始酸度0.90 mmol NaOH/10 g。在此混菌固态发酵工艺条件下进行3组平行试验,测得酒糟饲料中粗蛋白含量为（24.97±0.05）%,感官评价最终得分18分,等级为优良。研究结果对混菌固态发酵酒糟制备蛋白饲料具有一定的指导价值。     

黑曲霉固体发酵DDGS降解黄曲霉毒素初探

研究考察了不同发酵条件对玉米干酒糟及其可溶物(DDGS)黄曲霉毒素的生物降解效果。结果表明,在最优发酵条件下,发酵后DDGS黄曲霉毒素B1(AFB1)含量为1.84μg/kg,比发酵前AFB1 8.12μg/kg降解了77.34%,其固体发酵的优化工艺条件为菌液添加量6%、发酵温度30℃、发酵时间为60 h,由此,取得了较好的降解效果。     

不同类型白酒糟对西杂牛生长性能、养分表观消化率、血清生化指标及瘤胃发酵参数的影响

本试验旨在探讨不同类型白酒糟对西杂牛生长性能、养分表观消化率、血清生化指标及瘤胃发酵参数的影响。选取年龄(12月龄)、体重[(382.24±29.39) kg]相近的健康西杂(西门塔尔牛×本地黄牛)架子牛公牛120头,随机分为3组,每组40头牛。对照组饲喂基础饲粮,干酒糟组和发酵酒糟组分别饲喂用4.8%的干酒糟或发酵酒糟替换基础饲粮中部分原料配制的等能等氮饲粮。预试期7 d,正试期90 d。结果显示:1)添加干酒糟和发酵酒糟显著提高西杂牛的干物质采食量(P0.05),且添加发酵酒糟显著提高西杂牛的平均日增重并显著降低料重比(P0.05)。2)发酵酒糟组中性洗涤纤维消化率显著高于对照组和干酒糟组(P0.05)。3)添加干酒糟和发酵酒糟显著降低西杂牛血清尿素氮含量,且发酵酒糟组血清总蛋白、白蛋白、球蛋白、总胆固醇含量显著高于干酒糟组和对照组(P0.05)。4)发酵酒糟组瘤胃液总挥发性脂肪酸、乙酸、丁酸浓度显著高于对照组和干酒糟组(P0.05),pH显著低于对照组和干酒糟组(P0.05);干酒糟组瘤胃液乙丙比最高,显著高于对照组和发酵酒糟组(P0.05);干酒糟组和发酵酒糟组瘤胃液氨态氮浓度显著高于对照组(P0.05)。由此可见,饲粮中添加4.8%干酒糟或发酵酒糟可提高西杂牛采食量;添加4.8%发酵酒糟还可促进西杂牛瘤胃发酵,提高养分表观消化率及饲料报酬;综合比较,发酵酒糟对西杂牛的促生长效果优于干酒糟。     

酵母菌发酵有机米糠富锗的条件优化

试验以有机米糠为发酵底物,研究酵母菌对锗的生物富集作用,通过对富锗酵母生物量以及锗含量的测定,对此发酵试验的条件进行优化。试验结果显示:令初始p H值自然,米糠添加量32 g/250 ml、装液量80 ml/250 ml、接种量10%、时间60 h、温度30℃、GeO_2添加量为100 mg/l时,优化培养条件所得的富锗酵母菌发酵的有机米糠的有机锗生产水平为11.83 mg/kg。     

不同粗饲料组合对酒糟型饲粮体外发酵参数影响的研究

本试验旨在探讨不同粗饲料间的组合效应以及筛选出的最佳组合与精料固定比例组合对体外发酵参数的影响。利用体外产气法,将酱香型发酵酒糟、浓香型干酒糟、浓香型湿酒糟、酱香型湿酒糟分别与稻草、燕麦干草以0∶100、25∶75、50∶50、75∶25、100∶0的比例组合,分析体外发酵主要指标:产气量(GP)、pH、微生物蛋白(MCP)含量以及48 h产气量的单项组合效应指数(SFAEI);根据SFAEI,再将4种白酒糟与稻草、燕麦干草的最佳组合与相同精料混合(精粗比6∶4),分析体外发酵效果。结果表明:1)4种白酒糟与2种干草组合均能产生正组合效应,且与燕麦干草的组合效应优于与稻草的组合。2)最佳组合比例及SFAEI为:酱香型发酵酒糟∶燕麦干草=25∶75、SFAEI=11.48,浓香型干酒糟∶燕麦干草=25∶75、SFAEI=3.95,浓香型湿酒糟∶燕麦干草=50∶50、SFAEI=6.70,酱香型湿酒糟∶燕麦干草=25∶75、SFAEI=6.47。3)相同比例饲粮条件下,酱香型发酵酒糟组(60%精料+10%酱香型发酵酒糟+30%燕麦干草)甲烷产量显著低于浓香型湿酒糟组(60%精料+20%浓香型湿酒糟+20%燕麦干草)和酱香型湿酒糟组(60%精料+10%酱香型湿酒糟+30%燕麦干草)(P<0.05),酱香型发酵酒糟组和浓香型干酒糟组(60%精料+10%浓香型干酒糟+30%燕麦干草)的二氧化碳产量也显著低于其余2个湿酒糟组(P<0.05),而挥发性脂肪酸(VFA)含量则显著高于2个湿酒糟组(P<0.05)。综上所述,根据SFAEI,酱香型发酵酒糟、浓香型干酒糟、酱香型湿酒糟与燕麦干草组合的最佳比例是25∶75,浓香型湿酒糟与燕麦干草组合的最佳比例是50∶50;根据气体成分及总VFA含量,酱香型发酵酒糟组和浓香型干酒糟组体外发酵效果更优。     

利用啤酒酿造副产物添加血粉和益生菌生产发酵蛋白质饲料的研究

我国啤酒生产每年会产生大量的副产物麦糟和废酵母,而屠宰行业也会产生大量的禽畜血液副产物,两者具有很高的营养价值,适合作为发酵饲料的原料加以利用。以麦糟为主料,加入血粉辅料,混合接种不同益生菌,通过测定发酵产物蛋白质含量、糖含量及总酸含量等指标,分别评价不同主辅料配料比、发酵时间、酵母菌及乳酸菌接种方式及接种量等因素对混合发酵饲料品质的影响,筛选生产发酵蛋白质饲料的最佳条件。结果表明：在血粉辅料添加量为15.00%、发酵温度为30 ℃、接种酵母菌单一菌种且接种量为2.00%、发酵时间为5 d的条件下,获得的发酵产物品质较好,蛋白质含量达到50.36%,与初始样品的蛋白质含量相比,提升幅度达到75.53%;利用酵母菌及乳酸菌混合发酵时,先接入1.00%乳酸菌发酵2 d后,再接入1.00%酵母菌继续发酵至7 d时,产物的蛋白质含量达到59.27%,与初始样品的蛋白质含量相比,提高幅度达到106.59%。利用上述2种发酵方式得到的产品可作为良好的蛋白质饲料。     

Growth performance of nursery pigs fed diets containing increasing levels of corn distiller's dried grains with solubles originating from a modern Midwestern ethanol plant

Two experiments were conducted to determine the effects of including distiller's dried grains with solubles in nursery diets on growth performance, and to establish maximum inclusion rates for corn distiller's dried grains with solubles originating from modern, "new-generation" ethanol plants (built since 1990). Ninety-six crossbred pigs (BW = 6.18 +/- 0.14 kg) were blocked by gender and ancestry, and pigs within each block were randomly assigned to one of six dietary treatments (four pigs/pen, four pens/dietary treatment) in each of two growth performance experiments. Dietary treatments provided 0, 5, 10, 15, 20, or 25% distiller's dried grains with solubles during Phases 2 and 3 of a three-phase nursery feeding program for early-weaned pigs. Pigs in Exp. 1 were slightly older (19.0 vs. 16.9 d of age) and heavier (7.10 vs. 5.26 kg) at the beginning of the experiment compared to pigs in Exp. 2. All pigs in both experiments were provided a commercial pelleted Phase 1 diet for the first 4 d after weaning and were then switched to their respective experimental Phase 2 diets, which were fed for 14 d, followed by their respective Phase 3 experimental diets, which were fed for a subsequent 21-d feeding period. Experimental diets were formulated to contain equivalent apparent ileal digestible lysine (1.35 and 1.15%), apparent ileal digestible methionine + cystine (0.80 and 0.65%), ME (3,340 and 3,390 kcal/kg), calcium (0.95 and 0.80%), and total phosphorus (0.80 and 0.70%) within Phases 2 and 3, respectively. Overall growth rate, ending body weight, and feed conversion were similar among pigs regardless of dietary distiller's dried grains with solubles level for both experiments. In Exp. 1, feed intake was not affected by dietary treatment (P > 0.10). In Exp. 2, however, increasing the level of distiller's dried grains with solubles linearly decreased feed intake (P < 0.02) during Phase 2 and tended to decrease voluntary feed intake (P < 0.09) over the length of the experiment. These results suggest that the corn distiller's dried grains with solubles used in this study can be included in Phase 3 diets for nursery pigs at dietary levels of up to 25% without negatively affecting growth performance after a 2-wk acclimation period. Including high levels of corn distiller's dried grains with solubles in diets for pigs weighing less than 7 kg in BW, however, may negatively influence feed intake and growth.     

上海地区季节变化对奶牛产奶性能影响的研究

为探讨上海地区季节性变化对奶牛产奶量的影响,笔者采集2006年1月~2007年10月基础产奶量数据共17284牛次,分析季节变化对奶牛生产性能的影响。结果表明,12、1和2月份分娩的母牛产奶量较高,7、8、9和10月份分娩的母牛产奶量较低,其他月份居中;10、8、7和9 月份4个自然月产奶量极显著低于其他月份,其中9月份最低,而其他各月份差异不明显;奶牛分娩后不同泌乳月份产奶量由高到低的顺序是2、3、4、1、5、6、7、8、9、10和大于10个月龄。季节对奶牛的产奶性能有明显影响,应根据季节制定不同的饲养管理任务和采取相应的饲养措施,同时建议对奶牛的DHI记录也应考虑季节的影响。     

Simultaneous measures of rates of ruminal digestion and passage of feeds for prediction of ruminal nitrogen and dry matter digestion in lactating dairy cows

Three ruminal-cannulated Holstein cows in early lactation were fed three diets, each containing different energy and protein supplements in two consecutive 3 X 3 Latin squares. Each supplement contained a combination of three different feedstuffs (ground corn, soybean meal and wheat mids; corn gluten feed, rolled oats and distiller's dried grains; ground barley, brewer's grains and cottonseed meal). Diets consisted of 30% corn silage, 10% alfalfa hay, 10% alfalfa haylage, 17.7% ground corn plus minerals and vitamins, with the remainder as supplemental feedstuffs individually marked for measurement of ruminal turnover and in situ digestion rates. An extra period at the end of each Latin square was used to measure ruminal turnover and in situ digestion of individual forages. Diet had no effect on dry matter intake or milk yield. Mean fractional turnover (per hour) rate, measured by labeling feedstuffs with cerium, samarium or lanthanum was .044, .048, .049, .043, .047, .046, .050, .047, .049, .037, .046 and .045 for corn, soybean meal, wheat mids, corn gluten feed, oats, distiller's dried grains with solubles, barley, brewer's dried grains, cottonseed meal, alfalfa hay, corn silage and alfalfa haylage (P greater than .1), respectively. In situ-predicted ruminal degradation of N weighted for rate of passage was 61.4, 67.0, 81.5, 74.8, 86.3, 71.0, 75.7, 52.1, 54.2, 60.8, 71.7 and 70.9% for respective feedstuffs (P less than .05). In comparison with mean literature values for in vivo-measured N degradability, mean literature value = 1.172 (in situ predicted) -9.73 (P less than .05, R2 = .51). Results are interpreted to indicate a tendency for overestimating ruminal N degradability by in situ methods in feedstuffs of low degradability, while underestimating degradability in more highly degraded feedstuffs. Estimates were 11 to 17 percentage units lower than literature values for alfalfa hay and haylage and 17 units lower than literature values for distiller's dried grains.     

紫花苜蓿青贮为主的混合发酵饲料研究

以分别晾晒4h、8h、12h和24h后调制的紫花苜蓿青贮为主要原料,添加8％豆粕和22％玉米粉后进行二次青贮,室温贮藏45d后取样分析.结果表明：添加豆粕和玉米粉能显著改善晾晒4h、8h后青贮的紫花苜蓿青贮饲料再次青贮的发酵品质（P＜0.05）,而对于晾晒12h、24h后青贮的紫花苜蓿青贮饲料,添加组的发酵品质普遍较差;第二次青贮后,氨态氮占总氮的百分含量随着晾晒时间增加而显著降低（P＜0.05）.晾晒4h、8h后青贮的紫花苜蓿青贮饲料再添加玉米粉和豆粕调制混合发酵饲料是可行的,其中以晾晒4h后青贮的紫花苜蓿青贮饲料为原料效果最佳.     

乳清奶酒发酵最佳工艺条件的研究

乳清奶酒因其具有丰富的营养价值和独特的风味而深受广大消费者的喜爱。本试验采用乳清粉为原料,研究奶酒发酵生产工艺。配制10%的乳清粉溶液,在35℃下用0.7%乳糖酶水解乳清粉3 h,然后向其中添加30%的蔗糖,经高压灭菌锅121℃,15 min的杀菌处理,冷却至28℃,添加1%酵母进行发酵,在25℃下发酵5 d~7 d,生产出具有奶香风味的乳清奶酒。经正交试验,得出发酵的最佳条件为：添加蔗糖量为30%,酵母菌发酵温度25℃,酵母添加量1%。     

混菌固态发酵白酒糟开发为蛋白质饲料的条件优化及营养价值评定

本试验旨在优化白地霉、米曲霉、绿色木霉和枯草芽孢杆菌混菌固态发酵白酒糟开发为蛋白质饲料的条件,并评定其营养价值。将白地霉、米曲霉、绿色木霉和枯草芽孢杆菌按照1∶1∶1∶1混合后按10%接种到培养基中,采用L16(54)正交试验设计,共5个发酵条件,分别为基料、尿素、磷酸二氢钾、p H、水分,每个条件4个变量,共16组发酵条件。按条件配制好的混合物放置于(30±2)℃中培养72 h。对发酵前后真蛋白质、粗纤维含量进行极差分析确定最优条件,再比较最优条件发酵前后白酒糟营养水平和氨基酸组成的变化。结果显示:1)基料按照80%白酒糟、10%麸皮、5%玉米粉、5%菜籽粕配比,尿素添加量为1.5%,磷酸二氢钾添加量为0.7%,p H为5、水分为50%时发酵效果最好,为最优发酵条件。2)最优条件下发酵后白酒糟与发酵前相比,真蛋白质含量提高了57.85%(P0.01);粗纤维、酸性洗涤纤维、中性洗涤纤维、粗脂肪含量分别降低了42.39%、31.95%、27.73%、21.48%(P0.01);钙、磷含量分别提高了16.67%和68.18%(P0.01);总氨基酸含量提高了24.47%,其中赖氨酸、蛋氨酸、苏氨酸、缬氨酸、亮氨酸、异亮氨酸和脯氨酸含量分别提高了109.68%、38.09%、39.39%、71.43%、28.93%、10.87%和3.70%。综上可得,利用白地霉、米曲霉、绿色木霉和枯草芽孢杆菌混菌发酵白酒糟的最佳条件是:基料组成80%白酒糟、10%麸皮、5%玉米粉、5%菜籽粕,尿素1.5%,磷酸二氢钾0.7%,p H 5,水分50%,发酵产物的真蛋白质含量为24.34%。     

蜂蜜花粉醋工艺优化

蜂蜜花粉醋是利用蜂蜜和花粉作为原料,经过酵母菌的酒化发酵,再经过醋酸菌的醋酸发酵,制得营养丰富、对人体具有保健作用的调味品。在固体酵母添加量为0.5%和醋酸菌接种量为10%的条件下,讨论蜂蜜浓度、花粉的处理方法和添加量、醋酸发酵起始酒精度及时间对产品感官质量和发酵速度的影响,以确定产品的最佳配方及发酵工艺。     

Brewer's yeast efficiently degrades phytate phosphorus in a corn-soybean meal diet during soaking treatment

Microbes such as yeast and Aspergillus are known to produce phytase, and Aspergillus phytase has been used as a feed additive for improving phytate-phosphorus bioavailability in monogastric animals. We measured phytase activity in some by-products from fermented food and beverage productions by yeast and Aspergillus . The phytase activity was as high as 3577 and 2225 PU/kg DM in raw and dried brewer's yeasts, respectively. On the other hand, the phytase activity was approximately 400 PU/kg DM in white-wine yeast and red-wine yeast. The phytase activity was further low in natto (fermented soybean) residue, soy sauce cake, rice brewer's grain and the activity was not detected in dried corn-barley distiller's grain with soluble and sweet-potato distiller's residue. The stability of phytase against pepsin was much lower in the brewer's yeast than in an Aspergillus phytase preparation. On the other hand, the addition of raw brewer's yeast effectively degraded phytate phosphorus in a corn-soybean meal diet during soaking. These results suggest that phytase in the examined by-products is not suitable for the phytase source of conventional diets, but that the soaking treatment with a raw brewer's yeast is an alternative method for improving phytate-phosphorus bioavailability in corn-soybean meal diets for pigs.