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 16S 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 23.09 μmol/g to 12.65 μmol/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.