Low-Carbohydrate Tolerant LAB Strains Identified from Rumen Fluid: Investigation of Probiotic Activity and Legume Silage Fermentation

Abstract

The objective of this study was to isolate and characterize lactic acid bacteria (LAB) with low carbohydrate tolerance from rumen fluid and to elucidate their probiotic properties and the quality of fermentation of Medicago sativa L. and Trifolium incarnatum L. silage in vitro. We isolated 39 LAB strains and screened for growth in MRS broth and a low-carbohydrate supplemented medium; among them, two strains, Lactiplantibacillus plantarum (Lactobacillus plantarum) RJ1 and Pediococcus pentosaceus S22, were able to grow faster in the low-carbohydrate medium. Both strains have promising probiotic characteristics including antagonistic activity against P. aeruginosa, E. coli, S. aureus, and E. faecalis; the ability to survive in simulated gastric-intestinal fluid; tolerance to bile salts; and proteolytic activity. Furthermore, an in vitro silage fermentation study revealed that alfalfa and crimson clover silage inoculated with RJ1 and S22 showed significantly decreased pH and an increased LAB population at the end of fermentation. Also, the highest lactic acid production was noted (p < 0.05) in LAB-inoculated silage vs. non-inoculated legume silage at high moisture. Overall, the data suggest that RJ1 and S22 could be effective strains for fermentation of legume silage.

Pediococcus pentosaceus, a future additive or probiotic candidate

“…Isolated from rumen fluid, P. pentosaceus S22, with low carbohydrate tolerance, exhibited good adaptability to the gastric juice environment. Research showed that P. pentosaceus S22 greatly improved the quality of fermentation of legume silage in vitro [ 70 ]. Eveno et al [ 71 ] proposed that P. pentosaceus ICVB491 produced bacteriocins and biofilms with low pathogenic risks and high compatibility.…”

Application and Future Prospective of Lactic Acid Bacteria as Natural Additives for Silage Production—A Review

“…The current practice of silage-making combines several LAB strains [61][62][63][64][65] to induce silage fermentation (alfalfa, legumes, maize, grains, meadow, etc.) through a synergistic action, thus enhancing the stability for more than one year of storage [66].…”

In vitro assessment of safety and functional probiotic properties of Lactobacillus mucosae strains isolated from Iranian native ruminants intestine

“…Based on the previous studies, in vitro assessments, such as acid, bile and pancreatic enzymes tolerance, and survey some physiological characteristics (such as optimum growth temperature and salt sensitivity) have been considered as a good indicator to evaluate the probiotic properties of a bacterial isolates (Kim et al 2019;Kuppusamy et al 2020). After preliminary growth assays under acidic condition, seventy LAB isolates exhibited good survivability to pH ¼ 3 (data not shown).…”

“…Lactic acid bacteria (LAB) have been used as probiotics to modulate the composition of intestinal microbiota to promote the health of the host intestine (de Moraes et al 2017). LAB isolates have been isolated from a variety of sources, including fermented and dairy products, plants, soil and various organs of poultry, cattle or fish (Kuppusamy et al 2020). In addition, large amounts of LAB with vital function have been found in the ruminant's digestive tract (Timmerman et al 2006).…”