Technical University of Łódź, Institute of Fermentation Technology and Microbiology, Łódź, Poland.
Pol J Microbiol. 2010;59(4):257-63.
The probiotic potential of 3 yeasts strains of Saccharomyces cerevisiae isolated from kefirs and feces was investigated and compared with 3 isolates from medicines and 2 collection strains (ATCC) of Saccharomyces cerevisiae var. boulardii. Genetic identification of yeasts based on karyotypes indicated their affiliation to Saccharomyces spp. although chromosomal polymorphism was observed. Concerning probiotic characteristics survival in simulated gastric and intestinal environment were examined. The survival of all tested yeasts in medium of pH 2.5 was comparable and equaled 86.8-97.1% after 8 hours of incubation at 37 degrees C. The fecal isolate, probiotic and collection yeasts showed also high resistance to pH 1.5 and their survival was 85.3-92.1%, whereas for kefir strains it amounted to 33.1 and 38.9%. All yeasts tested demonstrated high resistance to synthetic bile salts as well. In the presence of 0.1% sodium cholate and sodium deoxycholate the reduction of cell number by only 1 log unit after 4 hours of incubation at 37 degrees C was observed. However, 1.0% addition of ox bile did not affect their viability. In simulated gastric and intestinal environment survival of fecal, probiotic and collection strains was 86.3-93.7% after 4 hours of incubation in media with addition of 3 g/l pepsin and 1 g/l pancreatin. Kefir isolates were more sensitive to these conditions and a further 10% reduction of cell number in relation to probiotic yeasts was observed. The tested strains, except for kefir isolates, were able to grow at 37 degrees C. All the tested strains survived in sufficient number to create the possibility of proper action in the human body, although fecal, probiotic and collection strains tolerated the conditions of the human gastrointestinal tract better than food-borne yeasts.
从开菲尔和粪便中分离出的 3 株酿酒酵母菌株的益生菌潜力与 3 株来自药物的分离株和 2 株酿酒酵母收藏株（ATCC）进行了比较。基于核型的酵母遗传鉴定表明它们属于酿酒酵母属。尽管观察到染色体多态性。关于益生菌特性，研究了在模拟胃和肠道环境中的生存能力。所有测试的酵母在 pH 2.5 的培养基中的存活率相当，在 37°C 孵育 8 小时后等于 86.8-97.1%。粪便分离株、益生菌和收藏酵母对 pH 1.5 也具有高抗性，其存活率为 85.3-92.1%，而开菲尔菌株则为 33.1%和 38.9%。所有测试的酵母对合成胆盐也具有高抗性。在 0.1%的胆酸钠和脱氧胆酸钠存在下，在 37°C 孵育 4 小时后，细胞数量仅减少 1 个对数单位。然而，添加 1.0%牛胆酸并不影响其活力。在添加 3g/L 胃蛋白酶和 1g/L 胰蛋白酶的培养基中，在模拟胃和肠道环境中孵育 4 小时后，粪便、益生菌和收藏株的存活率为 86.3-93.7%。开菲尔分离株对这些条件更敏感，与益生菌酵母相比，细胞数量进一步减少了 10%。除开菲尔分离株外，测试的菌株能够在 37°C 下生长。所有测试的菌株都能够以足够的数量存活下来，从而有可能在人体中发挥适当的作用，尽管粪便、益生菌和收藏菌株比食物来源的酵母更能耐受人体胃肠道的条件。
