摘要或動機

現今乳酸菌飲料風行，但是乳酸菌是否真能通過胃酸的考驗，到達腸道進行複製，利益人體？我們首先以市售乳酸菌粉（加拿大Rosell 公司，含二種菌，暫時命名為"小毛"及"小白"）為預測菌種，利用分光光度計測定乳酸菌於Thioglycollate 培養基中的生長能力（OD600）。小毛在pH 值 1、 3 、5、 7 時之生長力分別為0、 0.008 、0.682 、0.847 ，小白為 0、 0.015 、0.973、 0.636。若於培養基中添加不同濃度的螺旋藻熱分解物，如加入0.01%的添加物後，小毛在以上各種pH 值生長力分別為0.042、1.291, 、1.447, 、1.213 ，小白為 0.053、1.392、 1.531、 0.988，意外發現可大幅提升菌的生長力及抗酸力。再取台灣市售4 種廠牌優酪乳（以甲、乙、丙、丁代表之），分離乳酸菌，再於各種pH 值中培養。結果在pH 3 時，螺旋藻熱分解物僅對丙廠牌有效, 乙廠牌無效, 甲與丙則有無填加生長力都很差。在pH 1 時, 則對乙、丙、丁皆有效，故建議廠商慎選菌種，並於製程及成品中添加螺旋藻熱分解物。The yogurt is a popular drink. But whether the lactobacilli inside can resist the destruction of gastric acid and grow well in the intestinal tract is still questionable. We used pure lactobacilli powder (Rosell Company, Canada, containing two bacteria named in this report as "Little Hair" and "Small White") for pre-test. The growth ability in thioglycollate medium was determined by spectrophotometer (OD600). The results of bacterial growth at pH 1, 3, 5, and 7 for "Little Hair" were 0, 0.008, 0.682, and 0.847, respectively. Those for "Small White" were 0, 0.015, 0.973, and 0.636, respectively. After supplement with 0.01% of the boiled lysate of Spirulina algae (ProBio Biotech, Taiwan), growth abilities at pH 1, 3, 5, and 7 for "Little Hair" were 0.042, 1.292, 1.447, and 1.213, respectively. Those for "Small White" were 0.053, 1.392, 1.531, and 0.988, respectively. The algae extract amply promotes the growth and acid-resistance, especially at pH 3, of these bacteria. The lactobacilli isolated from four different products of yogurt in Taiwan, named as A, B, C, and D, were then tested as above. Results showed the supplement with the boiled lysate of Spirulina algae was very effective, at pH 3, for promoting growth of C, but not effective for B. Growth abilities of both A and D were very unsatisfactory with or without this supplement. At pH 1, algae lysate supplement significantly improved the growths of B, C, and D. Therefore, this supplement in culture and product for yogurt preparation was suggested.