高产酸菌株的筛选、鉴定及其混菌发酵对菜籽粕营养价值的影响

本实验从泡菜水中分离得到一株高产有机酸的乳杆菌,并将该菌株与黑曲霉混合后结合两步法处理菜籽粕,同时降解菜籽粕中的硫苷和大分子蛋白并提高总酸含量,从而提高菜籽粕的营养价值。该株乳杆菌经16S rDNA鉴定,确定为类食品乳杆菌(Lactobacillus paralimentarius)。将该菌株与黑曲霉混合后结合两步法处理菜籽粕后,其营养价值得到了一定提高,与空白对照和单菌发酵相比,总酸含量分别提高了640.54%、160.95%和112.40%;酸溶蛋白和氨基酸态含量分别从2.87%和0.12%提高到19.08%和1.23%;硫苷含量从23.09 μmol/g下降到12.65 μmol/g。结果表明,混菌发酵结合两步法有利于改善菜籽粕的营养价值,对扩大菜籽粕的利用奠定了基础。

Screening and Identification of High Acid Producing Strain and the Effect of Mixed Fermentation on the Nutritional Value of Rapeseed Meal

In this study,a Lactobacillus was separated from the pickle water with high production of organic acid,and was mixed with Aspergillus niger combined with two-step method to treat rapeseed meal,which can degrade glucosinolates and macromolecular proteins,increase of total acid content,and improve the nutritional value of rapeseed meal.This strain was identified as Lactobaillus paralimentarius by 16 S rDNA.The nutritional value of rapeseed meal was improved after treatment by this strain mixed with Aspergillus niger and combined with two-step method.Compared with blank control and single strain fermentation,the content of total acid was improved by 640.54%,160.95%,and 112.40%,respectively.The content of acid soluble protein and amino acid nitrogen were increased from 2.87%and 0.12%to 19.08%and 1.23%,respectively.The content of glucosinolates was also decreased from 23.09μmol/g to 12.65μmol/g.The results showed that mixed fermentation with two-step method could improve the nutritional value of rapeseed meal and the utilization of rapeseed meal was expanded.