米曲霉0-8固态发酵条件优化及其发酵产物对肉仔鸡日粮养分消化的影响

试验通过筛选高产蛋白酶米曲霉及其固态发酵条件优化，获得高酶活固态发酵物，并应用于肉仔鸡日粮，以期为提高肉仔鸡日粮蛋白质等养分利用提供技术手段。经过对8种不同米曲霉孢子产品进行初筛、复筛后获得一株产酸性蛋白酶较高的米曲霉菌株0-8，采用单因素和正交试验设计，对其产酸性蛋白酶发酵条件进行优化。结果表明：米曲霉菌株0-8产酸性蛋白酶培养的最适温度30℃、发酵时间66 h、初始水分47.40%、接种量1.5×107个/mL、麸皮含量80%、碳氮比（C/N）为1/3，优化后酸性蛋白酶活力达14 416.64 U/g，比优化前提高了157.02%。在肉仔鸡日粮中添加米曲霉0-8发酵物500 mg/kg，经过适应期10 d、正试期5 d的饲养试验，结果表明：与对照组相比，添加米曲霉0-8发酵物对粗蛋白质及能量消化率均有一定提高，但差异不显著（P>0.05）。日粮添加米曲霉发酵物有益于肉仔鸡的生产，但其添加水平及方式有待进一步研究。

Optimization of 0-8 Aspergillus oryzae Solid State Fermentation Conditions and the Effect of Fermented Product on Nutrient Digestion of Broiler

The high-yield protease was obtained by screening high-yield protease Aspergillus oryzae and optimizing its solid-state fermentation conditions, and then the effect of fermented product on nutrient digestion in broiler was studied. After the screening and re-screening of 8 different Aspergillus oryzae spores, a new Aspergillus oryzae strain 0-8 with high acid protease was obtained. The fermentation conditions of acid protease were optimized by single factor and orthogonal test experiment. The results showed that the optimum temperature was 30℃, the most suitable fermentation time was 66 h, the initial water content was 47.40%, the inoculation quantity was 1.5×10⁷ spores/mL, the content of bran was 80%, C/N was 1/3, the optimized vigor of acid protease reached 14 416.64 U/g, which was 157.02% higher than that before optimization. 500 mg/kg Aspergillus oryzae 0-8 fermented product was added in the broiler diet, and the mutrient digestibility of broiler were measured after 10 d of adaptation and 5 d of test period. The results of the nutrient digestion of broilers showed that feeding Aspergillus oryzae 0-8 fermentation increased the CP and energy digestibility of broiler in a certain degree compared to control group, but there's no significant difference (P>0.05). Dietary supplementation of Aspergillus oryzae fermentation was beneficial to the production of broilers, but its additive dose or feeding pattern should be further studied.