Isolation, identification, and application of yeast strains from the local ecosystem of Summer Black vineyard

Abstract

Several indigenous yeast strains originating from the local ecosystems of Summer Black vineyard in Jingjiang, Jiangsu, China, were isolated and identified using Wallenstein Laboratory (WL) medium combined with 26S rDNA D1/D2 region sequence analysis. The 18 isolated colonies were classified into four different culture types. Two yeast strains were selected for vinification of Summer Black wines, and the volatile compounds were analyzed by headspace solid-phase microextraction–gas chromatography-mass spectrometry (HS-SPME/GC-MS). 2,3-butanediol, ethyl octanoate, ethyl hexanoate, and ethyl decanoate were the key odor-active compounds. The wines vinificated using the two selected yeast strains had higher quantities of identified compounds than that vinificated by commercial yeast. The two yeast strains isolated from the local ecosystem of Summer Black vineyard were more effective in producing aroma in Summer Black wines than commercial yeast was. This study will give some guidance or fundamental data toward wine making and yeast selection and fermentation. Novelty impact statement Saccharomyces cerevisiae and Brettanomyces bruxellensis were two main strains isolated from local “Summer Black” grape yard located in Jingjiang, Jiangsu Province, China. 2,3-butanediol, ethyl octanoate, ethyl hexanoate, and ethyl decanoate were major contributors to the flavor of the grape wine. The two yeast strains were much more effective in producing aroma in wine than commercial yeast strain BV818.