Identification of Lactobacillus Strains Capable of Fermenting Fructo-Oligosaccharides and Inulin

Abstract

Novel probiotic strains that can ferment prebiotics are important for functional foods. The utilization of prebiotics is strain specific, so we screened 86 <i>Lactobacillus</i> strains and compared them to <i>Bifidobacterium breve</i> 2141 for the ability to grow and produce SCFA when 1% inulin or fructo-oligosaccharides (FOS) were provided as the carbon source in batch fermentations. When grown anaerobically at 32 °C, ten <i>Lactobacillus</i> strains grew on both prebiotic substrates (OD₆₀₀ ≥ 1.2); while <i>Lactobacillus coryniformis</i> subsp. <i>torquens</i> B4390 grew only in the presence of inulin. When the growth temperature was increased to 37 °C to simulate the human body temperature, four of these strains were no longer able to grow on either prebiotic. Additionally, <i>L. casei</i> strains 4646 and B441, and <i>L. helveticus</i> strains B1842 and B1929 did not require anaerobic conditions for growth on both prebiotics. Short-chain fatty acid analysis was performed on cell-free supernatants. The concentration of lactic acid produced by the ten <i>Lactobacillus</i> strains in the presence of prebiotics ranged from 73-205 mM. <i>L. helveticus</i> B1929 produced the highest concentration of acetic acid ~19 mM, while <i>L. paraplantarum</i> B23115 and <i>L. paracasei</i> ssp. <i>paracasei</i> B4564 produced the highest concentrations of propionic (1.8-4.0 mM) and butyric (0.9 and 1.1 mM) acids from prebiotic fermentation. <i>L. mali</i> B4563, <i>L. paraplantarum</i> B23115 and <i>L. paracasei</i> ssp. <i>paracasei</i> B4564 were identified as butyrate producers for the first time. These strains hold potential as synbiotics with FOS or inulin in the development of functional foods, including infant formula.