Nutrient consumption patterns of Lactobacillus acidophilus

Abstract

BackgroundOne of the largest challenges in using Lactobacillus acidophilus as a probiotic is acid stress. The current research aimed to identify substances that help L. acidophilus resist acid stress; this was achieved through assessing its nutrient consumption patterns at various pH conditions.ResultsThe consumption rates of alanine, uracil, adenine, guanine, niacin, and manganese were consistently higher than 60% for L. acidophilus LA‐5 cultured at pH 5.8, 4.9 and 4.4. The consumption rates of glutamic acid + glutamine and thiamine increased with decreasing pH and were higher than 60% at pH 4.9 and 4.4. The viable counts of L. acidophilus LA‐5 were significantly increased under the corresponding acidic stress conditions (pH 4.9 and 4.4) through the appropriate addition of either alanine (3.37 and 2.81 mM), glutamic acid + glutamine (4.77 mM), guanine (0.13 and 0.17 mM), niacin (0.02 mM), thiamine (0.009 mM) or manganese (0.73 and 0.64 mM) (P < 0.05). The viable counts of L. acidophilus LA‐5 cultured in a medium supplemented with combined nutritional factors was1.02–1.03‐fold of the counts observed in control medium under all acid conditions (P < 0.05).ConclusionAlanine, glutamic acid + glutamine, guanine, niacin, thiamine and manganese can improve the growth of L. acidophilus LA‐5 under acidic environment in present study. The results will contribute to optimising strategies to enhance the acid resistance of L. acidophilus and expand its application in the fermentation industry.This article is protected by copyright. All rights reserved.