Studies on the Brewing of Apple Wine -Culture Conditions of a Cider Yeast, Saccharomyces sp. R-11 on the Synthetic Medium

사과주(酒) 양조(釀造)에 관한 연구(硏究) -사과주효모(酒酵母) Saccharomyces sp. R-11의 합성배지((合成培地)에서의 배양(培養) 조건(條件)-

As a primary study for cell growth and alcohol production of a cider yeast, Saccharomyces sp. R-11, cultural and nutritional characteristics of the strain were investigated. The results obtained were as follows: The optimum culture medium for this strain was a synthetic medium, Henneberg B, and sucrose was the best carbon source for yeast growth and alcohol production. Optimum sugar concentrations for yeast growth and alcohol production were 15% and 25%, respectively. Optimum pH and temperature of the basal medium for growth of this strain were 4.5 and $30^{\circ}C$ respectively. The yeast growth was enhanced by the addition of 100 ppm of $Mg^{2+}$, but significantly inhibited by the addition of 100 ppm of $Co^{2+}$. Lower temperature and maintenance of optimum pH for yeast growth increased the final alcohol concentration. Under optimum condition for cell growth at stationary culture, generation time and specific growth rate of the strain were 7.5 hr and 0.092 $hr^{-1}$, respectively. At 8% initial alcohol concentration, yeast growth was inhibited about 50% and this strain could not be grown at more than 12% initial alcohol. The strain could be grown at less than 125ppm $SO_2$without alcohol addition, and at less than 75 ppm $SO_2$ with 8% initial alcohol. The higher sulfur dioxide concentration of a medium, the longer lag phase in yeast growth was observed. This strain could induced alcoholic fermentation at less than 10% initial alcohol concentration with 0 and 25 ppm $SO_2$, at less than 8% initial alcohol with 50 and 75 ppm $SO_2$, and at less than 6% initial alcohol with 100 and 125 ppm $SO_2$.

사과주(酒) 효모(酵母)의 Saccharomyces sp. R-11의 배양조건(培養條件)을 균생육(菌生育)과 알코올생성(生成)의 측면(側面)에서 검토(檢討)한 결과(結果)는 다음과 같다. 기본배지(基本培地)로서는 Henneberg B 배지(培地)가 가장 양호(良好)하였으며 탄소원(炭素源)으로 sucrose가 가장 우수하여 균(菌)의 생육면(生育面)으로는 15%, 알코올생성(生成)을 위해서는 25% 첨가(添加)가 가장 적당하였다. 공시균(供試菌)의 생육(生育)을 위한 최적(最適) pH는 4.5, 온도(溫度)는 30^{\circ}C$였다. 한편 $Mg^{2+}$ 첨가(添加)는 균생육(菌生育)을 촉진(促進)시켰으며$Co^{2+}$는 저해(沮害)하였다. 알코올생성(生成)은 배양온도(培養溫度)가 낮을수록, 최적(最適) pH에 가까울수록 양호(良好)하였다. Generation time은 정치배양시(靜置培養時) 최적생육조건(最適生育條件)에서 7.5시간(時間)이었으며 specific growth rate 0.092 $hr^{-1}$이었다. 균생육(菌生育)은 알코올농도(濃度) 8%에서 약 50% 저해(沮害)되었으며 12% 이상(以上)에서는 거의 불가능(不可能)하였다. 본공시균(本供試菌)은 알코올 무첨가시(無添加時) $SO_2$ 125ppm까지, 알코올농도(濃度) 8%에서는 75ppm까지 생육(生育)이 가능(可能)하였으며, $SO_2$ 농도(濃度)가 높아질수록 lag phase가 길어지는 경향(傾向)을 보였다 알코올농도(濃度)와 $SO_2$ 관계에서는, 균생육(菌生育)은 초기(初期) 알코올농도(濃度) 6%까지는 $SO_2$ 농도(濃度)에 관계없이 별(別)다른 차(差)가 인정되지 않았으며, $SO_2$ 무첨가(無添加) 및 25ppm에서는 초기(初期) 알코올농도(濃度) 10%, $SO_2$ 50ppm 및 75ppm에서는 8%, $SO_2$ 100 및 125ppm에서는 초기(初期) 알코올농도(濃度) 6%까지 알코올생성(生成)이 가능했다.