Selection of lactic acid bacteria for enhancing the quality of elephant grass silage

Abstract

The goal of this study was to characterize the elephant grass silages lactic acid bacteria population to further select promising strains to be used as inoculants and to evaluate its effects on elephant grasscultivar BRS Capiaçu silage. In the experiment one, the isolation of LAB (lactic acid bacteria) from elephant grass silages and the characterization and selection of these strains and the previously isolated from maize and sugarcane silages were done. In the experiment two, thirteen strains showed the highest growth, pH reductioninteresting metabolites production and ability to inhibit the growth of undesirable microorganisms. The strain CCMA 0170 was evaluated in elephant grass cultivar BRS Capiaçu silage during 60 days of ensilage. The chemical composition, fermentative characteristics, DM loss, microorganisms population and aerobic stability were evaluated. The fermentative process of elephant grass silage was characterized by a succession of Lactobacillus sakei, L. plantarum group, Pediococcuspentosaceus and L. brevis. The silages inoculated with CCMA 0170 (L. hilgardii, CCMA 1394 and CCMA 1402 (L. plantarum), CCMA 1409 (L. brevis), CCMA 1363 and CCMA 1364 (L. farraginis) strains showed lower losses of DM and high aerobic stability. The CCMA1364 strain showed the lowest yeast populations in the silages inoculated with CE78, CE90, CCMA 1364, CCMA 1366, CCMA 0173 and CCMA 0170 strains. During the strains evaluation, was evidenced that, although strains isolated from the silage itself are adapted to the characteristics of the forage. It is possible to find isolated strains of different silages that can be promising for further use in different forages. This highlights the importance of the research and evaluation of new strains adapted to the fermentative process of each forage.