Effect of Homo-Fermentative Lactic Acid Bacteria Inoculants on Fermentation Characteristics and Bacterial and Fungal Communities in Alfalfa Silage

Abstract

We evaluated the effects of a homo-fermentative lactic acid bacteria (homo-LAB) inoculant on the fermentation and microbial communities of alfalfa ensiled at two dry matter (DM) contents of 38 and 46% DM. At both DMs, alfalfa was treated or not with an inoculant containing Pediococcus acidilactici, Enterococcus faecium and Lactobacillus plantarum at a targeted application rate of 165,000 cfu/g of fresh weight and stored for 3, 30 and 60 days. Treatment with the inoculant resulted in a lower drop in pH and, in general, higher lactic acid and lower acetic acid when applied to medium DM silage. For the four most abundant microbial genera, increased abundances of Bacteroides and Lactobacillus (p < 0.05), as well as decreased abundances of Muribaculaceae were observed in high DM and inoculated silages. The abundance of Prevotellaceae-UCG-001 was lower in medium DM control silages than in high DM control silages. Inoculation and DM affected abundances of Vishniacozyma (p < 0.05). Increased abundances of Vishniacozyma, as well as decreased abundances of Leucosporidium were observed in medium DM-inoculated silages. Changes in the relative abundance (RA) of the main populations of bacteria and yeasts did explain the fermentation and nutrition differences among treatments.

The microbial communities and natural fermentation quality of ensiling oat (Avena sativa L.) harvest from different elevations on the Qinghai-Tibet Plateau

“…Vishniacozyma (also known as Cryptococcus ) has been isolated from soil and wheat, but there are limited reports regarding this genus in silage. It is reported that Vishniacozyma could assimilate lactic acid and D-lactose ( Tian et al, 2022 ; Li X. et al, 2022 ). Vishniacozyma was observed in both fresh and ensiled oat in the study, indicating the fresh oat might be subjected to soil contamination before ensiling.…”

Effects of Different Types of LAB on Dynamic Fermentation Quality and Microbial Community of Native Grass Silage during Anaerobic Fermentation and Aerobic Exposure

“…LAB strains have been increasingly used to preserve the silage quality and increase feed utilization rates in recent years [ 8 , 9 , 10 ]. Homofermentative and heterofermentative LAB inoculation has commonly been used to improve the fermentation quality of silage [ 11 , 12 , 13 ]. The product of homolactic fermentation is lactic acid, which promotes silage fermentation, rapidly lowers the pH of silage, and inhibits the growth of harmful microorganisms [ 14 , 15 ].…”