Hanseniaspora uvarum FS35 degrade putrescine in wine through the direct oxidative deamination pathway of copper amine oxidase 1

Putrescine is abundant in wine and have toxicological risks for the health of consumers. Certain microbes with oxidative deamination activity are considered to be one of the most effective ways to degrade putrescine. The characterization and possible mechanism of putrescine degradation by Hanseniaspora uvarum FS35 were studied in this work. Hanseniaspora uvarum FS35 was selected from 111 yeast strains by UPLC analysis and exhibited the ability to eliminate > 44.5 mg/L of putrescine after 12 h of culture. Transcriptome analysis showed that by adding putrescine as a nitrogen source, the gene expression level of copper amine oxidase 1 (CuAO1) increased, leading to a coordinated response in the oxidative deamination of putrescine to 4-amino-butanal and subsequent dehydrogenation to 4-amino-butanoate. The purified recombinant protein CuAO1 could degrade 25.8 and 21.8 mg/L of putrescine in Marselan and Cabernet Sauvignon wines, respectively. H. uvarum FS35 was then inoculated sequentially with Saccharomyces cerevisiae into Cabernet Sauvignon grape juice, and the physiochemical indexes and aroma compounds were detected by HPLC and HS-SPME/GC-MS, respectively. wines produced from sequential inoculations showed significantly lower level of putrescine and higher amounts of glycerol, lactic acid, acetic acid, phenylethyl alcohol, ethyl acetate and β-phenylethyl acetate compared with the control fermentation of commercial S. cerevisiae, which proved the potential of H. uvarum FS35 as a promising strategy to reduce biogenic amines in wines.