Biotransformation of alkylamides and alkaloids by lactic acid bacteria strains isolated from Zanthoxylum bungeanum meal.

Zanthoxylum bungeanum meal (ZBM) is the by-product of Z. bungeanum seeds after pressing. It is restricted as a feed additive because it contains stimulating and potentially harmful substances, which are alkylamides and alkaloids. This study described the use of Lactobacillus paracasei and L. acidipiscis isolated from ZBM in solid-state fermentation of ZBM to reduce the concentration of undesirable alkylamides and alkaloids. By optimizing the substrate and fermentation conditions, the minimum contents of alkylamide and alkaloid were 2.96 and 3.20 mg/g, and the degradation rates reached 51.86% and 39.59%, respectively. Moreover, the biotransformation pathways of hydroxyl-α-sanshool and chelerythrine were established by identifying the metabolites. Bacterial diversity was shift significantly, and the relative abundance of Lactobacillus increased from 0.10% to 99.0% after fermentation. In conclusion, this study introduced a reliable strategy for processing ZBM as a feed additive.