Resumo

LEY DE-COSS, Alejandro et al. Comparative estudio between strain Pediococcus acidilactici aisolated from rumen sheep and a ruminal bacteria group. Agrociencia [online]. 2013, vol.47, n.6, pp.567-578. ISSN 2521-9766.

The objective of this study was to evaluate Pediococcus acidilactici (PA) in vitro to determine production of lactic, acetic, propionic and butyric acids, as well as changes in pH, when added to a culture medium with high proportion of non-structural carbohydrates. The experimental design was completely randomized, the lyophilized culture of PA (T1) was evaluated and compared with a group of bacteria of the rumen fluid (RF). The inocula were added to an anaerobic culture medium with D-(+ )-glucose (5 %), plus a high-energy diet; besides the addition of monensin (MO) and lasalocid (LA) to the medium was evaluated. Media were incubated at 38± 0.5 °C for 3, 6 and 12 h; after each period it was assessed the concentration of lactic acid, volatile fatty acids (VFA), pH, concentration of total bacteria (TB) and lactic acid bacteria (LAB). The results were analyzed using the GLM procedure and by Wilcoxon rank-sum test for TB and LAB concentrations. Lactic acid production was greater (p≤ 0.05) in the media inoculated with PA and RF without ionophores, but pH at 12 h of incubation did not change, although pH was reduced since 3 h in all treatments including those with lower production of lactic acid (p≤ 0.05), whereas production of total VFA was similar among treatments. The greatest amount (p≤ 0.05) of BT was found in the media without ionophores inoculated with RF, compared to those inoculated with PA; the greatest amount of LAB was found in treatments without ionophores. Under these conditions P. acidilactici had a heterofermentative activity producing similar amounts of lactic, acetic, propionic and butyric acids regarding RF; in addition it was sensitive to the ionophores used.

Palavras-chave : rumen; total bacteria; lactic acid bacteria; volatile fatty acids; ionophores.

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