固态发酵对棉籽粕脱毒效果的影响

Effect of Solid-state Fermentation on Virus-free of Cottonseed Meal

[目的]优化棉籽粕微生物脱毒条件,降低棉籽粕中的游离棉酚含量。[方法]利用米曲霉3042固态发酵降解棉籽粕中的游离棉酚,通过单因素试验和正交试验,研究接菌量、发酵温度、料水比和发酵时间对棉籽粕脱毒的影响,确定棉籽粕微生物脱毒的最优脱毒条件。[结果]极差分析表明,影响发酵棉籽粕游离棉酚含量的4个因素主次顺序依次为料水比>发酵温度>接菌量>发酵时间。正交试验表明,棉籽粕微生物最优脱毒条件为:米曲霉3042接菌量5%,发酵底物添加0.5%尿素和1%蔗糖,料水比1∶0.83,5℃发酵48 h。在此条件下,游离棉酚含量降至117 mg/kg,降解率达到78.13%,发酵棉籽粕粗蛋白含量达到40.16%,较发酵前提高了12.87%。[结论]该研究为生产能够达到饲用标准的棉籽粕饲料提供了科学依据。

[Objective] The study aimed to optimize the conditions for the biological virus-free of cottonseed meal and decrease the free gossypol content in the cottonseed meal.[Method] The solid state fermentation was performed by Aspergillus oryzae 3042 to degrade the free gossypol in the cottonseed meal.The effects of the inoculum size,fermentation temperature,solid-liquid ratio and fermentation time on the virus-free of cottonseed meal were studied and the optimum conditions for the biological virus-free of the cottonseed meal were confirmed through the single factor test and orthogonal test.[Result] The range analysis showed that the effects of 4 factors on the free gossypol content in the fermented cottonseed meal were in order of solid-liquid ratio fermentation temperature inoculum size fermentation time.The orthogonal test showed that the optimal conditions for biological virus-free of of cottonseed meal were as follows：A.oryzae 3042 inoculum size of 5%,cottonseed meal with addition of 0.5% urea and 1% sucrose,solid-liquid ratio of 1∶0.8,fermentation temperature of 35 ℃ and time of 48 h.Under the conditions,the content of free gossypol reduced to 117 mg/kg and the ratio of degradation reached 78.13%;the crud protein content in the fermented cottonseed meal reached 40.16%,being 12.87% higher than the one before the fermentation.[Conclusion] The study offered the scientific basis for the production of the cottonseed meal feed that could meet the feeding standard.