Heterologous expression and characterization of amine oxidases from Saccharopolyspora to reduce biogenic amines in huangjiu

High content of biogenic amines in fermented food has adverse effects on the human body. Previous studies showed that biogenic amines could be reduced in some fermented foods using enzymes. However, this process was barely explored in alcoholic beverages. In this study, potential biogenic amine degarding genes were cloned from Saccharopolyspora hirsuta F1902 and Saccharopolyspora hordei F2002, and expressed in E. coli to study the enzymatic activities of copper-containing amine oxidases named as CaoAShi and CaoASho in huangjiu. The degradation ratio of total biogenic amines by CaoAShi (31.72%) was higher than that of CaoASho (24.37%). CaoAShi and CaoASho had the highest degradation ratios of histamine, phenylethylamine, followed by tyramine, tryptamine or putrescine, and the smallest was cadaverine. The results indicated that CaoAShi had better biodegradability of biogenic amines than CaoASho in huangjiu (P < 0.05), and the two enzymes had the same amine substrate characteristics. These results provide new insights for the reduction of biogenic amines using amine oxidases, which is useful not only for huangjiu brewing industry, but also for other fermented food industries.