Effect of the Molecular Structure and Degree of Polymerization of Fructans on the Growth Behavior of Four Lactic Acid Bacteria

The effects of linear and branched fructans from chicory and agave, respectively, and of different degrees of polymerization (DP) were evaluated on the growth curves of Lactobacillus acidophilus, Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, and Lactobacillus rhamnosus. Native fructans from agaves were separated into fractions with different DPs using the ultrafiltration process. The fructan profile was determined by size exclusion chromatography (high-performance liquid chromatography (HPLC)-SEC) and grouped according to their DPs. The growth was evaluated by the specific growth rate (μ) using turbidimetry (nephelometric turbidity unit (NTU)) at 860 nm for 12–22 h in modified De Man–Rogosa–Sharpe (MRS) broth, using fructans as a carbohydrate source. The different tested strains exhibited varying growth rates under the tested treatments, and the highest growth was obtained with agave fructooligosaccharides (FOS) in a range between 4 and 50% of the four LAB evaluated in comparison with linear fructans, so they can be considered for the development of new functional foods and pharmaceutical industries.