Gotcheva Velitchka, Petrova Galya, Petkova Mariana, Kuzmanova Yordanka, Angelov Angel
Department of Biotechnology University of Food Technologies Plovdiv Bulgaria.
Primoris Bulgaria Plovdiv Bulgaria.
Eng Life Sci. 2018 Jun 13;18(11):820-830. doi: 10.1002/elsc.201800054. eCollection 2018 Nov.
In the recent years, consumers' interest in healthy diet opened a new field for functional food development through combining the valuable composition of cereals and the health-promoting properties of lactic acid bacteria (LAB). LAB with amylolytic properties can assimilate starch in a single-step process and could be successfully applied as starter cultures offering an efficient nutritional conversion of cereal matrices. The probiotic potential of amylolytic LAB has not been investigated so far, therefore the present study focused on the molecular screening and in vitro tests of five amylolytic strains to assess their tolerance to high acid and bile salts concentrations and antibiotic resistance as basic characteristics required for probiotic strains selection. Results showed excellent correspondence between the genetic screening and the phenotypic tests performed. Survivability at high acidity and bile salts presence was strain specific, with significant positive effect observed for cultures in stationary phase compared to those in exponential phase. Effect of starch in the medium proved most important to ensure viability of the amylolytic strains, which reveals the excellent potential of amylolytic LAB for commercially relevant probiotic applications. The strains proved to be generally safe in terms of antibiotic resistance. Among the five tested strains, Bom2 showed the best probiotic potential.
近年来，消费者对健康饮食的兴趣通过将谷物的宝贵成分与乳酸菌（LAB）的健康促进特性相结合，为功能性食品的开发开辟了一个新领域。具有淀粉分解特性的LAB可以在单步过程中同化淀粉，并可以成功地用作发酵剂，实现谷物基质的高效营养转化。迄今为止，尚未对具有淀粉分解能力的LAB的益生菌潜力进行研究，因此，本研究集中于对五株淀粉分解菌株进行分子筛选和体外测试，以评估它们对高酸和高胆汁盐浓度的耐受性以及抗生素抗性，这些是选择益生菌菌株所需的基本特征。结果表明，基因筛选与所进行的表型测试之间具有极好的对应性。在高酸度和存在胆汁盐的情况下的存活率具有菌株特异性，与处于指数生长期的培养物相比，处于稳定期的培养物具有显著的积极影响。培养基中淀粉的作用被证明对确保淀粉分解菌株的活力最为重要，这揭示了具有淀粉分解能力的LAB在商业相关益生菌应用中的巨大潜力。这些菌株在抗生素抗性方面总体上被证明是安全的。在五个测试菌株中，Bom2显示出最佳的益生菌潜力。
