## 1 Introduction  
The fermentative aromas compounds (including esters, higher alcohols, and volatile fatty acids) are one of the principal attributes determining wine quality and influence the preferences of wine consumers [1]. Besides the strains of _Saccharomyces cerevisiae_, nutritional status of grape musts largely influences the aroma quality of the final wine products. The physiology and metabolism of wine yeasts can be affected significantly with even small changes in the most composition, and consequently alter the formation of fermentative aroma compounds [2]. Until now, much work has been carried out to investigate the effect of sugar (glucose and fructose), nitrogen (ammonium or amino acid), and carboxylic acids (malic and tartaric acid) on aroma compounds syntheses during wine fermentation [3, 4, 5], however, relatively little information is available on the function of unsaturated fatty acids (UFAs). UFAs is necessary for yeast under anaerobic conditions to maintain membrane integrity and adapt well to various environmental stresses during wine fermentation [6]. Our prior work indicated that UFAs can directly influence the synthesis of yeast-derived volatile compounds through regulating the expressions of related functional genes [7; 8]. It should be pointed out that although there are several studies investigating the impact of UFA variation on aromas biosynthesis during wine fermentation, the reported results are always inconsistent. For example, [PERSON] et al. [9] found that adding oleic acid and ergosterol increased most of higher alcohols and acetate esters production, while [PERSON] et al. [10] found that increasing the content of linoleic acid improved the production of C6 compounds and higher alcohols, but decreased acetate esters and some ethyl ester. In the study of synergistic effect, pre-fermentative addition of Tween 80 (containing 70% of oleic acid and 30% of stearic acid and palmic acid) increases the higher alcohols, esters, and volatile fatty acids of Chardonnay wine [11], which are partially in agreement with the results of [PERSON] et al. [12] in synthetic grape must MS300 with mixed addition of oleic acid, linoleic acid, and linolenic acid. In addition, the levels of major fermentative products (such as ethanol, glycerol, and acetic acid) are also varied. Obviously, these inconsistent results could be put down to the differences in amount and composition of UFAs added, fermentation conditions, grape medium, and wine yeast used. To rational modulate the levels of chemical and aromatic compounds by fine controlling UFAs, it is essential to elucidate their regulation mechanism. It is well-known that the syntheses of aroma volatiles are not only associated with functional gene expressions, but also the availability of precursors, the cellular redox potential, and the energy status of the cells [13]. Thus, the metabolism of yeast in response to UFAs variation needs to be characterized. In one recent study, [PERSON], [PERSON], and [PERSON] [14] investigated the effect of single fatty acid on the metabolism of wine yeast in white wine fermentation, and reported that the addition of different fatty acids affected the metabolism and growth of wine yeasts in a different way. Actually, UFAs in grape must contain a mixture of linoleic acid (C18:2, LA), oleic acid (C18:1, OA), and \(\alpha\)-linolenic acid (C18:3, ALA). Their concentrations vary with grape cultivar [15] and fermentation procedures [16], and it is thus essential to investigate their synergistic effect on yeast overall metabolism during wine fermentation. To our knowledge, there are no relevant research reports yet. In this work, the mixture of LA, OA, and ALA were pre-fermentative added in Cabernet Sauvignon juice. Considering that different wine yeast strains might show distinct metabolism profiles when response to the same nutritional condition and produce wines with diverse aroma compounds due to the yeast's genetic variations, two wire yeast strains (EC1118 and BDX) were used in this study, respectively.