Selection of lactic acid bacteria from native grass silage and its effects as inoculant on silage fermentation

Abstract

AbstractThe study aimed to isolate, characterize, and identify wild lactic acid bacteria (LAB) strains from native grass silage on the Inner Mongolian Plateau, and the effects of wild LAB strains on the nutritive and fermentation characteristics of sorghum–sudangrass hybrid (Sorghum bicolor L. × S. sudanense L.) silage were also investigated. These isolates were evaluated using morphological, physiological, and biochemical tests. Three isolated strains were Gram‐positive, homofermentative, catalase‐negative, not produce gas from glucose, and rod‐shaped. These strains could grow normally at pH 3.5–8.0, 15–30 ˚C and NaCl 3 and 6.5%. They were identified as Lactobacillus plantarum group by sequencing 16S rRNA. Compared to uninoculated silage, all LAB‐inoculated silages significantly (P < .05) increased lactic acid (LA) content and ratios of lactic acid/acetic acid (LA/AA), while, reduced pH and ammonia nitrogen (NH3–N). Among all the isolated LAB strains, XM2 showed the highest (P < .05) crude protein (CP), LA, ratio of LA/AA and LAB, lowest (P < .05) pH, AA, propionic acid (PA), butyric acid (BA), NH3–N than the other isolated LAB strains. Strain XM2 is a potential starter culture for sorghum–sudangrass hybrid silage.