Effects of Class IIa Bacteriocin-Producing Lactobacillus Species on Fermentation Quality and Aerobic Stability of Alfalfa Silage

Abstract

The effects of two strains of class IIa bacteriocin-producing lactic acid bacteria, Lactobacillus delbrueckii F17 and Lactobacillus plantarum (BNCC 336943), or a non-bacteriocin Lactobacillus plantarum MTD/1 (NCIMB 40027), on fermentation quality, microbial counts, and aerobic stability of alfalfa silage were investigated. Alfalfa was harvested at the initial flowering stage, wilted to a dry matter concentration of approximately 32%, and chopped to 1 to 2 cm length. Chopped samples were treated with nothing (control, CON), Lactobacillus delbrueckii F17 (F17), Lactobacillus plantarum (BNCC 336943) (LPB), or Lactobacillus plantarum MTD/1 (NCIMB 40027) (LPN), each at an application rate of 1 × 106 colony-forming units/g of fresh weight. Each treatment was ensiled in quadruplicate in vacuum-sealed polyethylene bags packed with 500 g of fresh alfalfa per bag and ensiled at ambient temperature (25 ± 2 °C) for 3, 7, 14, 30, and 60 days. The samples were then subjected to an aerobic stability test after 60 days of ensiling. Compared with the CON silage, the inoculants reduced the pH after 14 days of ensiling. After 60 days, pH was lowest in the LPB-treated silage, followed by the F17 and LPN-treated silages. Inoculation of F17 increased concentrations of lactic acid in silages fermented for 7, 14, 30, and 60 days relative to other treatments, except for the LPN-treated silages ensiled for 30 and 60 days, in which the lactic acid concentrations were similar to that of F17 silage. Application of F17 and LPB decreased the number of yeast and mold relative to CON and LPN-treated silages. Compared with the CON silage, inoculant-treated silages had greater aerobic stability, water-soluble carbohydrate, and crude protein concentrations, and lower neutral detergent fiber, amino acid nitrogen, and ammonia nitrogen concentrations. The LPB-treated silage had the greatest aerobic stability followed by the F17-treated silage. Both class IIa bacteriocin producing inoculants improved alfalfa silage fermentation quality, reduced the growth of yeasts and molds, and improved the aerobic stability of the ensiled forage to a greater extent than the proven LPN inoculant. However, higher crude protein concentration and lower ammonia nitrogen concentration were observed in LPN-treated silage relative to other treatments.

Effects of treating Prosopis juliflora pods with multienzyme, with and without bacterial cultures on in vitro dry matter digestibility (IVDMD), fermentation kinetics, and performance of growing pigs

“…It is therefore, possible that naturally fermented prosopis pod meal had less organic matter and sugars available during pepsin-pancreatine digestion thus the low digestibility. On the contrary, fermentation that uses inoculants such as Lactobacillus plantarum is usually associated with less organic matter loss and dry matter loss (Li et al 2020). This is consistent with Tabacco et al ( 2011) who reported a reduction in the dry matter lossafter ensiling forage crop treated Lactobacillus treatment, relative to untreated silage.…”

Waste processing method and environmental protection in the agro-industrial complex

“…Strains of lactic acid bacteria of the genus Lactobacillus were selected on the basis that they are a natural inhabitant of the intestinal microflora of animals and are a proven inoculant widely used in traditional ensiling [11,12]. They have the ability to improve the aerobic stability of the feed without adversely affecting the productivity of animals [13].…”

Effects of inoculation of Lactiplantibacillus plantarum and Lentilactobacillus buchneri on fermentation quality, aerobic stability, and microbial community dynamics of wilted Leymus chinensis silage

“…Despite the improved preservation quality, Cai et al (1999) discovered that the L. plantarum inoculation was ineffective at preventing yeast growth, resulting in aerobically deteriorated alfalfa, Italian ryegrass, and sorghum silages. However, Li et al (2020) discovered that L. plantarum-producing class IIa bacteriocins improved alfalfa silage fermenting quality, reduced mold and yeast levels, and improved aerobic stability. Acetic acid promotes aerobic stability by inhibiting the growth of unfavorable bacteria such as molds and yeasts (Wilkinson and Davies, 2013).…”

“…Beneficial bacteria reduce aerobic deterioration by producing a variety of metabolites, in addition to improving fermentation quality. For example, LAB-producing class IIa bacteriocins could improve silage fermentation quality, lower mold and yeast counts, and improve aerobic stability (Li et al, 2020). Mold has been linked to mycotoxin production, whereas enterobacteria can ferment WSCs into products such as lactic and acetic acids (Mcdonald et al, 1991).…”