Influence of Lactobacillus spp. from an Inoculant and of Weissella and Leuconostoc spp. from Forage Crops on Silage Fermentation

摘要

Lactobacillus spp. from an inoculant andWeissella and Leuconostoc spp. from forage crops were characterized, and their influence on silage fermentation was studied. Forty-two lactic acid-producing cocci were obtained from forage crops and grasses. All isolates were gram-positive, catalase-negative cocci that produced gas from glucose, and produced more than 90% of their lactate in the d-isomer form. These isolates were divided into groups A and B by sugar fermentation patterns. Two representative strains from the two groups, FG 5 and FG 13, were assigned to the species Weissella paramesenteroides and Leuconostoc pseudomesenteroides, respectively, on the basis of DNA-DNA relatedness. Strains FG 5, FG 13, and SL 1 (Lactobacillus casei), isolated from a commercial inoculant, were used as additives to alfalfa and Italian ryegrass silage preparations. Lactic acid bacterium counts were higher in all additive-treated silages than in the control silage at an early stage of ensiling. During silage fermentation, inoculation with SL 1 more effectively inhibited the growth of aerobic bacteria and clostridia than inoculation with strain FG 5 or FG 13. SL 1-treated silages stored well. However, the control and FG 5- and FG 13-treated silages had a significantly (P P P W. paramesenteroides FG 5 andL. pseudomesenteroides FG 13 did not improve silage quality and may cause some fermentation loss.