## 1 Introduction  
Ethanol is the main product in wine produced by yeast during alcoholic fermentation. During the last two decades, in many different geographical areas, the average alcohol level has risen about 2% (\(v/v\)) [1].  
Generally, the alcohol level in wine is between 12 and 14% (\(v/v\)) with some exception the different varieties of wines [2].  
The climatic changes recorded in recent years have resulted in grapes with high sugar concentrations, which is reflected in wines with increased ethanol content. Wines with high ethanol content are associated with health issues, economic and quality aspects [3, 4, 5, 6, 7, 8, 9, 10, 11, 12].  
Indeed, high alcohol levels in wine compromise the organoleptic properties of the product increasing the hotness and viscosity, and decreasing sweetness, intensity, and aromatic flavors [13, 14, 15, 16, 17, 18, 19, 20]. The combination of these aspects (organoleptic, economic and health issues) in wine with high ethanol content has led to the development of technological strategies to produce wines with a reduced alcohol level without affecting flavour profile and sensorial characteristics [21]. For these reasons, many strategies in reduce ethanol content in wine during the winemaking process have been proposed, such as viticultural, pre-fermentation, fermentation and post fermentation practices [1, 8, 22, 23].  
A suitable strategy for reducing the alcohol level of wine is the use of non-_Saccharomyces_ yeasts able to use different pathways for sugar convert (respiration, alcoholic fermentation, and glycerol-pyruvate metabolism) [24, 25, 26]. Biotechnological processes under different fermutation conditions with non-_Saccharomyces_es in co-culture or sequential fermentation with _S. cerevisiae_ starter strain were proposed [22; 27; 28; 29; 30; 31; 32].  
In sequential inoculation, the non-_Saccharomyces_es yeast strain is inoculated in the grape juice in the first stage of fermentation (48-72 h). This procedure allows the non-_Saccharomyces_es strain to take advantage favouring its metabolic activity. In particular, the non-_Saccharomyces_es yeasts could affect the wines by producing a low ethanol yield, low volatile acidity and/or enhancement of specific analytical and aromatic compounds [33; 34; 35; 36]. Different researches showed that the physiological features of _Metschikowia pulcherrina Lachancea thermotolerans, Torulanspora delbrueckii, Stammetella_ and _Zygosaccharomyces_ spp. strains are suitable for lower ethanol content in wine in the presence of oxygen. According with the results obtained by controlled aeration fermentations the ethanol reduction was for _M. pulcherrina_ 1.6% (_v/v_), _T. delbrueckii_ 0.9% (_v/v_), _Z. bailii_ 1.0% (_v/v_), and _S. bacillaris_ 0.7% (_v/v_) compared with _S. cerevisiae_ wine [31; 37]. In recent previous work, _Starmerella bombicola_ (formerly _Candida stellata_) was evaluated for ethanol reduction in wine in a static condition and in a immobilized form with promising results [32]. However, immobilized cells are a modality of inoculum, quite complex and difficult to apply under an industrial unification condition.  
Previously, a strain of _S. bombicola_ was proposed to enhance the glycerol content of wine in immobilized form to overcome its low fermentation rate [38]. Indeed, the general enological traits of _S. bombicola_ strains showed low fermentation rate and low fermentation power (4-5% vol. of ethanol) together with some interesting positive features as high glycerol and succinic acid production.  
In the present work, with the aim to reduce the ethanol content in wine, _S. bombicola_/_S. cerevisiae_ sequential fermentations were evaluated under partial aeration condition. The analytical composition and aromatic profile of the final wines were also evaluated.