Multi-omics analyses of the mechanism for formation of key aroma-active compounds in blood orange wine fermented by Pichia kudriavzevii.

Pichia kudriavzevii is an emerging non-Saccharomyces yeast recognized for its ability to enhance aroma quality in fermented foods, though the precise mechanisms underlying its effects remain poorly understood. This study delves into the influence of P. kudriavzevii BP15 on the formation of key aroma-active compounds (KAACs) and metabolic pathways during the fermentation of blood orange wine. By integrating multi-omics approaches, including volatilomics, genomics, and transcriptomics, this work systematically evaluated the profile of volatile organic compounds (VOCs), pinpointed the genes implicated in KAACs metabolism, and elucidated the biotransformation pathways of KAACs. The volatilomics results demonstrated that inoculation with P. kudriavzevii BP15 significantly improved the complexity and desirability of aroma by promoting the accumulation of diverse VOCs, particularly esters. The genomics analysis further revealed that a substantial portion of P. kudriavzevii BP15 genome was dedicated to carbohydrate, amino acid, and energy metabolisms. The transcriptomics data identified the high expression of multiple genes (e.g., ARO8, ACC1, ALD4, ILV5) during the early stages of fermentation by P. kudriavzevii BP15 that are integral to the biosynthesis of KAACs. These insights provide a deeper understanding of P. kudriavzevii BP15's potential application in the production of high-quality blood orange wine, underscoring its role in enhancing the aroma profile through sophisticated metabolic interventions.