DOI: 10.11118/978-80-7701-093-1-0156

YEAST SUPPRESSION AND ENHANCED AEROBIC STABILITY IN GRASS SILAGE INOCULATED WITH LENTILACTOBACILLUS BUCHNERI SUBSP. SILAGEI NCIMB 30673

Kerley, A.¹, Borkowska, A.¹, Jones, P. B.¹, Smith, P.¹, Leggett, M. J.¹

¹ Volac International Ltd, Port Talbot, United Kingdom

Heterofermentative lactic acid bacteria (LAB) inoculants are used to enhance silage aerobic stability by increasing acetic acid production, which inhibits yeasts and moulds. Lentilactobacillus buchneri is widely used in such products, but strain-specific effects and the speed at which they provide effective protection remain poorly defined. This study evaluated a novel candidate inoculant, L. buchneri subsp. silagei strain NCIMB 30673, for its ability to improve the early aerobic stability of grass silage. Grass (33% DM) was chopped and ensiled in triplicate 1.8 L silos for 30 or 92 days, either left untreated or inoculated with L. buchneri silagei at 1.0 × 10⁵ CFU/g fresh forage. At opening, silages were analysed for microbial counts, pH, fermentation products, and aerobic stability. Data were analysed by linear models with the interaction between time and treatment as a fixed effects, followed by emmeans pairwise comparisons at each time point (p ≤ 0.05). At 30 days, inoculation with the L. buchneri significantly reduced yeast populations compared with the untreated control (3.16 log₁₀ CFU/g reduction, p < 0.001). The L. buchneri substantially increased acetic acid and 1,2propanediol concentrations relative to untreated silage (day 30, both p < 0.001), indicating rapid activity within as little as 30 days. Aerobic stability measurements suggested that inoculated silage opened at day 30 remained stable for >11 days, whereas untreated silage deteriorated earlier (3 days). By day 92, both treatments had similar yeast and acetic acid levels, likely due to naturally occurring heterofermentative bacteria present in the untreated silage. The new L. buchneri subsp. silagei strain NCIMB 30673 rapidly enhanced acetic acid and 1,2-propanediol production in grass silage and substantially reduced yeast populations by day 30 post-ensiling, indicating strong antifungal activity. These findings suggest that NCIMB 30673 is a promising candidate silage inoculant to improve aerobic stability and control spoilage yeasts, even after short ensiling periods.

Keywords: Lentilactobacillus buchneri subsp. silagei, silage inoculant, aerobic stability, yeast suppression, acetic acid production

pages: 156-157, Published: 2026, online: 2026