【作者】 付弘赟；

【导师】 李吕木；

【作者基本信息】 安徽农业大学 ， 动物营养与饲料科学， 2008， 硕士

【摘要】 豆粕来源广泛,营养丰富,是重要的植物性饲料蛋白源。但豆粕中存在的多种抗营养因子,极大地影响了它在幼龄动物饲粮中的大量使用。目前对豆粕中抗营养因子的处理方法多以化学、物理方法为主,有一定的去除作用,但存在安全性、成本高以及对豆粕中营养价值损失大等缺陷。本研究以微生物固态发酵手段对普通生豆粕进行发酵处理,研究微生物发酵对豆粕中抗营养因子及其营养价值的影响。1.菌种和发酵条件对发酵豆粕中抗营养因子的影响。利用枯草芽孢杆菌、蜡样芽孢杆菌、植物乳酸菌,酪酸梭状芽孢杆菌四种菌种进行单菌发酵试验,采用多因素试验设计,研究接种量、含水量、发酵时间对各菌去除豆粕中胰蛋白酶抑制因子、植酸、脂肪氧化酶、凝集素等抗营养因子的影响。结果表明,枯草芽孢杆菌在料水比1:1、接种量9%,发酵48h条件下对豆粕中胰蛋白酶抑制因子及植酸的去除率分别达到65.36%和83.45%（P＜0.01）,此条件下脂肪氧化酶（lox1、lox2）也被完全灭活（P＜0.01）。枯草芽孢杆菌在料水比1:1.2、接种量9%,发酵48h条件下对凝集素的去除率达到90%（P＜0.01）。2.混菌发酵对发酵豆粕中抗营养因子的影响。以普通生豆粕为原料,选用用枯草芽孢杆菌、蜡样芽孢杆菌、植物乳酸菌和酵母菌进行混菌发酵,采用L₂₇(3¹³)正交试验设计研究混菌接种比例对豆粕各抗营养因子以及对小肽含量的影响,确定混菌发酵作用的主次菌种和最佳菌种接种比例。结果表明:混菌发酵中枯草芽孢杆菌:蜡样芽孢杆菌:植物乳酸菌:酵母菌最佳接种比例分别为6%:4%:4%:4%,在料水比1:1、发酵24h,pH自然条件下对胰蛋白酶抑制因子去除率达到75.89%、植酸去除率达到86.71%、大豆抗原蛋白完全去除（P＜0.01）。在去除胰蛋白酶抑制因子的效应中,枯草芽孢杆菌对胰蛋白酶抑制因子的影响极显著（P＜0.01）,蜡样芽孢杆菌次之,影响显著（P＜0.05）。枯草芽孢杆菌和酵母菌对植酸的去除中均达到显著水平（P＜0.05）,同时枯草芽孢杆菌在对增加小肽含量的效应中也有极显著影响（P＜0.01）。各菌在去除脂肪氧化酶、凝集素的效应中影响差异不显著（P＞0.05）。3.混合发酵去除豆粕中抗营养因子最佳发酵条件研究。以普通豆粕为原料,菌种接种比例为枯草芽孢杆菌:蜡样芽孢杆菌:植物乳酸菌:酵母菌=6%:4%:4%:4%,设定4个5水平的单因素试验,分别研究起始pH值、含水量、温度,发酵时间等因素对混菌发酵效果的影响,确定混菌发酵最佳发酵条件。结果表明,混菌发酵最佳条件为料水比1:1～1:1.2、发酵温度37℃、起始pH自然（6.5）,发酵时间60h,豆粕中胰蛋白酶抑制因子活性为10.21 mg/g,去除率达79.44%,植酸含量为0.07%,去除率为90.62%,凝集素含量为3.216μg/g,去除率达99.69%,脂肪氧化酶lox1活性为0.125,去除率达90%,而脂肪氧化酶lox2则被完全灭活。大豆抗原蛋白去除率达到95%,另外小肽含量也由2.7%增加至11.98%。更多还原

【Abstract】 Soybean meal is one of the high-grade vegetable protein sources.Its resource and nutrition are rich.But there are many kind of anti-nutrition factor in soybean meal which greatly influences its utilization in young stock’s feed.Nowadays people mainly use chemical or physical method to eliminate the anti-nutrition factors of soybean meal.It always costs too much and unsafe,although it has effect on elimination of anti-nutrition factors.We choose the microbe fermentation method to treat soybean meal so that to research the effect of microbe fermentation on anti nutrition factor and nutrition value of soybean meal.Experiment 1:Influence of different strains and fermentation conditions on anti-nutrient factors of fermented soybean meal.In this study,we used bacillus subtilis,bacillus cereus,lactobacillus,clostridium butyricum to apply polyfactorial experiment design to study the effect of inoculum size,moisture capacity and fermentation time on contents of anti-nutrition factors and small peptide in fermented soybean meal. Througth the experiment we concluded that:The elimination coefficient of trypsin inhibitor and phytic acid were 65.36%,83.45%fermentated by bacillus subtilis when inoculum size was 9%,moisture capacity was 1:1 and fermentation time was 48h（P＜0.01 ）, respectively,Lipoxygenase were eliminated completely under the same conditions （P＜0.01）.The effects of Bacillus subtilis on elimination of trypsin inhibitor is the best in all four strains we used.The elimination coefficient of lectin were 90%fermentated by bacillus subtilis when inoculum size was 9%,moisture capacity was 1:1.2 and fermentation time was 48h（P＜0.01）.Experiment 2:Effect of mixed culture fermentation on anti-nutrient factors of soybean Meal.In this study,we used raw soybean meal as raw material,and select bacillus subtilis,bacillus cereus,lactobacillus,clostridium butyricum to carry out the mix swains fermentation.Applying L₂₇(3¹³) orthogonal experiment design to study the effect of different mixed culture fermentation inoculum size ratios on anti-nutrition factors in fermented soybean meal.It was concluded that the best multi-strains inoculum size ratio was bacillus subtilis:bacillus cereus:laobacillus plantarum:clostridium butyricum= 6%:4%:4%:4%,that can removal the chief anti-nutrition factors in soybean meal greatly. The elimination coefficient of trypsin inhibitor,phytic acid and soybean protein were 75.89%,86.71%and 100%fermentated by bacillus subtilis when temperature was 34℃, moisture capacity was 1:1 and pH was nature（P＜0.01）.The results show that on removing trypsin inhibitor effects of bacillus subtilis affected significantly（p＜0.01）, Bacillus cereus affect significantly（p＜0.05）.Removed of phytic acid with multi-strains fermentation,bacillus subtilis and lactobacillus both had significant impact（p＜0.05）,and bacillus subtilis also had a very significant impact（p＜0.01） on improve peptide content in soybean meal fermented.Soybean protein was nearly eliminated completely.Experiment 3:Study of mixed culture fermentation optimization fermentation condition.In this study,we used raw soybean meal as raw material,and selected the best inoculum size ratio of multi-strains was bacillus subtilis:bacillus cereus:laobacillus plantarum:clostridium butyricum=6%:4%:4%:4%,apply five levels monomodule experiment design to study the effect of temperature,initiatial pH,moisture capacity and fermentation time on multi-strains fermentation effectiveness and determining the best multi-strains fermentation conditions.Comprehending the results,we conclude that bacillus subtilis 6%,bacillus cereus 4%,lactobacillus 4%,yeast fungus 4%,moisture capacity1:1,40℃,60h,initiatial pH natural are the best fermentation conditions.Finaly,, the content oftrpsin inhibitor,phytic acid and lectin were10.21mg/g,0.07%and 3.216ug/g, respectively.And the elimination coefficient of them were 79.44%,90.62%and 99.69%. The activity of lipoxygenase-1 was 0.125,its elimination coefficient was 90%. Lipoxygenase-2 was completely eliminated,and the elimination coefficient of soybean protein was more than 95%.And the content of small peptide increased from 2.7%to 11.98%.更多还原