Enzyme additives influence bacterial communities of Medicago sativa silage as determined by Illumina sequencing
Abstract This study aimed to evaluate the effects of enzymes (cellulase combined with galactosidase), and the combination of these enzymes with Lactobacillus plantarum (LP) on bacterial diversity using high-throughput sequencing. Alfalfa forages were treated with or without cellulase + ɑ-galactosidase (CEGA), cellulase + LP (CELP), or ɑ-galactosidase + LP (GALP). After 56 days of ensiling, all the treated silages exhibited improved fermentation quality, as reflected by decreased pH, ammonium-N and increased lactic acid levels compared to the control silage. Enzymatic treatment improved nutrient value by increasing the level of crude protein and decreasing the neutral detergent fibre (NDF) level. Treatment of the silage significantly changed the bacterial community, as determined by the PCoA test. LAB dominated the bacterial community of the treated silage after ensiling. The dominant bacteria from Garciella, Enterococcus, Lactobacillus and Pediococcus in the control silage changed to Lactobacillus and Pediococcus in the CEGA silage, and Lactobacillus in the CELP and GALP silages. Collectively, enzymes and enzymes in combination with inoculants both greatly increased the abundance of LAB, with Enterococcus, Lactobacillus and Pediococcus in the silage with enzymes only (CEGA) and Lactobacillus in the silage with a combination of enzymes and inoculants (CELP and GALP).