Probiotic Characteristics of Ligilactobacillus salivarius AS22 Isolated from Sheep Dung and Its Application in Corn-Fox Tail Millet Silage

Abstract

The forage crops corn (Zea mays) and foxtail millet (Panicum italicum L.) are widely used as animal feed because of their high nutritive values. The ensiling of corn and foxtail millet is often associated with the growth of undesirable microbes, which cause severe loss of dry matter content during the storage periods. The selection of suitable Ligilactobacillus species for corn-fox tail millet silage production can improve the quality. In this study, we aimed to select potent lactic acid bacteria (LAB) from sheep dung and analyses their biological application such as probiotic features, antimicrobial activities and fermentation capability of silage. A total of nine Lactobacillus strains were inoculated in MRS medium to evaluate lactic acid concentration. The isolated strain, Ligilactobacillus salivarius AS22, produced a higher lactic acid level (40.2 ± 2.2 µg/mL) with high growth rates (2.24 ± 0.12 OD at 600 nm) compared to other strains. The silage treated with inoculant (L. salivarius AS22) decreased the pH value (p < 0.05) and enhanced lactic acid production (p < 0.05) than the control at ensiled silages. LAB inoculated silage had reduced numbers of fungal colonies than control (p < 0.05). In conclusion, the addition of L. salivarius AS22 improved the quality of whole corn and foxtail millet silages with significant probiotic potential.