混菌发酵玉米豆粕型饲料最佳菌种配比研究

Screening of Best Strain Ratio of Corn-soybean Meal Feed Fermented by Mixed Strains

目的:研究优化黑曲霉、乳酸菌、枯草芽孢杆菌及酵母菌等4种混菌混合发酵玉米豆粕型饲料的最佳发酵菌种比例组合。方法:以黑曲霉、乳酸菌、枯草芽孢杆菌及酵母菌为4个因素,每个因素设定3个水平,按照L 9(34)正交试验表设计9组不同的菌种比例组合,总接种量按4%,发酵初始水分设定为36%,30℃条件下进行固态发酵,分别发酵48、72、96 h后测定样品pH值、乳酸含量及干物质回收率(DMR),优化其最佳发酵组合。结果:相同发酵时间内,黑曲霉、乳酸菌、枯草芽孢杆菌、酵母菌之比为3∶3∶2∶1时,样品pH值最低,发酵速度最快;相同发酵时间内,黑曲霉、乳酸菌、枯草芽孢杆菌、酵母菌比例为3∶3∶2∶1时,乳酸含量显著高于其他各菌种比例组合(P<0.05);发酵时间为72 h时,干物质回收率各组间无显著性差异(P>0.05),干物质损失在4.60%。结论:本试验条件下,黑曲霉、乳酸菌、枯草芽孢杆菌、酵母菌之比为3∶3∶2∶1时,发酵效果最好。

Objective:To study the optimum proportion of corn-soybean meal feed fermented by aspergillus niger,lactic acid bacteria,bacillus subtilis and yeast.Methods:Aspergillus niger,lactic acid bacteria,bacillus subtilis and saccharomyces cerevisiae were used as 4 factors,each factor was set at 3 levels,9 groups of different proportion combinations were designed according to L 9(34)orthogonal test table,the total inoculation amount was 4%,the initial water content was set at 36%,and solid-state fermentation was carried out at 30°C.After 48 h,72 h and 96 h,the pH value,lactic acid content and dry matter recovery(DMR)of the samples were determined.The optimam proportion was finally investigated.Results:In the same fermentation time,the ratio of aspergillus niger,lactic acid bacteria,bacillus subtilis and yeast was 1∶1∶1∶1,2∶2∶3∶1,3∶3∶2∶1 respectivly,the pH value of the sample was the lowest,the fermentation speed was the fastest,and the ratio of strain was 3∶3∶2∶1,the lactic acid content was significantly higher than that of other strains(P<0.05),and there was no significant difference in the dry matter recovery(P>0.05)and the dry matter loss was 4.60%.Conclusion:When the ratio of aspergillus niger,lactic acid bacteria,bacillus subtilis and yeast is 3∶3∶2∶1,the fermentation effect is the best.