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 without or with cellulase + ɑ-galactosidase (CEGA), cellulase + LP (CELP), ɑ-galactosidase + LP (GALP). After 56 days of ensiling, All the treated silages exhibited improved fermentation quality as reflecting by decreased pH, ammonium-N and increased lactic acid levels compared to the control silage. Enzymatic treatment improved nutrients value by increased the level of crude protein and decreased 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 control silage changed to Lactobacillus and Pediococcus in CEGA silage, and Lactobacillus in CELP and GALP silages. Collectively, enzymes and enzyme in combination with inoculants both greatly increased the abundance of LAB, with Enterococcus, Lactobacillus and Pediococcus in enzymes only silge (CEGA) and Lactobacillus in enzyme combination with inoculants silage (CELP and GALP).