菜籽粕混菌固态发酵制备多肽饲料的研究

Preparation of Bio-Feedstuff with Rich Peptides from Rapeseed Meal by Mixed Solid Fermentation

以菜籽粕为原料,以发酵产物中真蛋白质量分数、多肽得率和硫苷含量为评价指标,通过米曲霉、白地霉、热带假丝酵母、酿酒酵母和枯草芽孢杆菌的单菌及混菌发酵,进行最佳发酵菌种组合的研究;通过最佳混菌的单因素试验,研究在培养基中添加无机盐(CaCl2、K2HPO4、MgSO4、FeSO4和CuSO4)、氮源[CO(NH2)2、(NH4)2SO4、KNO3、NH4Cl和NH4HCO3)]、辅料(麸皮、玉米粉和米糠)和料水比对发酵效果的影响。以发酵产物的多肽得率为评价指标,通过正交试验优化培养基的组成。结果表明,白地霉和枯草芽孢杆菌为最佳发酵混合菌种;培养基中CaCl2是最好的无机盐,NH4Cl是最好的无机氮源,3种辅料的添加对发酵效果均没有显著的改善作用;最优培养基组成是:CaCl20.1%、NH4Cl 1.5%、料水比1∶1.2,使用最优培养基进行混菌发酵,多肽得率高达12.81%。

Rapeseed meal was used to prepare bio-feedstuff with rich peptide by single or mixed strains solid-fermentation.The used strains included Aspergillus oryzae（Ao）,Geotrichum candidum（Gc）,Candida tropicalis（Ct）,Saccharomyces cerevisiae（Sc） and Bacillus subtilus（Bs）.Effects of single or mixed strains solid-fermentation on contents of true protein,peptide and glucosinolate in the fermentation product were investigated to search optimal combination of cultures.Taking peptide content as evaluation index,the effects of inorganic salt（such as CaCl2,K2HPO4,MgSO4,FeSO4 and CuSO4）,nitrogen sources [such as urea CO（NH2）2,（NH4）2SO4,KNO3,NH4Cl and NH4HCO3],accessory（such as wheat bran,corn flour and rice bran） and solid/liquid ratio in the culture medium on the fermentation process were studied by single factor tests,and the composition of culture medium was optimized by an orthogonal experiment.Results：Gc and Bs is the optimal fermentation mixed strains;CaCl2 is the best inorganic salt in the culture medium and NH4Cl is the best nitrogen sources.Three kinds of accessory show no remarkable improvement on the fermentation effect.The composition of optimal culture medium is CaCl2 0.1%,NH4Cl 1.5% and solid/liquid ratio 1 ∶ 1.2.The product peptide content of fermentation with the optimal culture medium reaches12.81%.