Ferulic acid esterase (FAE) plays an important role in plant fiber degradation by catalyzing the hydrolysis of lignocellulosic structures. FAE-producing lactic acid bacteria (LAB), as potential probiotics, can improve ruminant digestion and gut health. In this study, two LAB strains (Q2 and Q6) with FAE activity were isolated from sheep rumen. Based on 16S rDNA sequencing, they were identified as Lactobacillus mucosae and Streptococcus equinus, respectively. Compared to Q2, Q6 demonstrated higher enzyme production, lactic acid yield, broader carbohydrate utilization, and stronger antimicrobial activity. The whole genome sequencing revealed Q2 and Q6 possess genomes of 2.14 Mbp and 1.95 Mbp, with GC contents of 46.81% and 37.30%, respectively. Q2 and Q6 exhibited the highest average nucleotide identity (ANI) with L. mucosae DSM 13345 (97.30%) and S. equinus ATCC 33317 (97.92%), respectively. The strains harbored 2101 and 1928 predicted genes, including 1984 and 1837 coding sequences (CDSs), respectively. GO enrichment analysis showed the CDSs predominantly associated with membranes (or cells), catalytic activity, and metabolic processes. KEGG analysis revealed both strains enriched in metabolic pathways, with Q6 showing a notably higher number of proteins in the ABC transporters and quorum sensing than Q2. Carbohydrate-active enzymes database (CAZy) profiling identified 75 CAZymes in Q2 and 93 CAZymes in Q6, with each strain containing one novel fae gene. Safety assessment identified 1 and 33 pathogenic genes, along with 2 and 4 putative antimicrobial peptide genes, in Q2 and Q6, respectively. Notably, Q6 carried 12 virulence factor genes. These findings suggest Q2 exhibits a superior safety profile compared to Q6, indicating a higher probability of Q2 being an effective probiotic strain. In conclusion, both LAB strains produce FAE. L. mucosae Q2 demonstrates suitability as a direct-fed probiotic for livestock, while Q6 exhibits potential as a silage inoculant, though comprehensive safety evaluations are required prior to its application.

This study used soybean meal as the substrate and systematically optimized its enzymatic hydrolysis through single-factor experiments and response surface methodology. A predictive model based on a Box–Behnken design was developed to improve protein hydrolysis efficiency and increase the yield of functional products. The optimal conditions were 1.45% enzyme addition, a reaction time of 62 h, a temperature of 36.5 °C, and a moisture content of 35%. Under these conditions, the small-peptide content increased 16.33-fold. Structural analyses showed that enzymatic treatment markedly disrupted the compact surface of soybean meal, converting it into a loose, porous matrix. In addition, enzymolysis altered the protein secondary structure from ordered α-helices and folded conformations to more disordered, flexible forms, thereby improving the molecular-weight distribution. Composition analyses showed an 114.2% increase in total free amino acids, including essential amino acids. Moreover, DPPH radical-scavenging activity increased from 18.37% to 57.99%. Overall, this study optimized the enzymatic hydrolysis conditions for soybean meal and provides valuable insights for the development of high-value protein-peptide products.

This study employed soybean meal as the substrate and systematically optimized its enzymatic hydrolysis process using a combination of single-factor experiments and response surface methodology. A predictive model based on the Box–Behnken design was established to improve protein hydrolysis efficiency and increase the yield of functional products. The optimal conditions identified were 1.45% enzyme addition, a reaction time of 62 h, a temperature of 36.5 °C, and a moisture content of 35%. Under these conditions, the small-peptide content increased by 16.33-fold. Structural analyses showed that enzymatic treatment markedly disrupted the compact surface of soybean meal, converting it into a loose and porous matrix. In addition, enzymolysis altered the protein secondary structure from ordered α-helices and folded conformations to more disordered and flexible forms, thereby improving the molecular-weight distribution. Composition analyses demonstrated a 114.2% increase in total free amino acids, including essential amino acids. Moreover, DPPH radical-scavenging activity increased from 18.37% to 57.99%. Overall, this study optimized the enzymatic hydrolysis conditions for soybean meal and provides valuable insights for the development of high-value protein-peptide products.

This study tested the hypothesis that dietary L. acidophilus would improve nutrient utilization in yellow-feathered broilers mainly through intestinal changes rather than a consistent increase in growth performance. A total of 195 one-day-old broilers were assigned to a control group (basal diet), a T1 group (basal diet with 10 g/kg L. acidophilus), or a T2 group (basal diet with 15 g/kg L. acidophilus), with five replicates of 13 birds per treatment over 63 days. The biological responses followed a clear pattern. First, supplementation did not significantly affect average daily feed intake, average daily gain, or feed-to-gain ratio at any growth stage or across the entire trial (days 1–63; p > 0.05), indicating limited direct effects on growth. Second, the main nutritional response occurred during days 22–42, when T1 increased the apparent nutrient digestibility of dry matter, organic matter, ether extract, crude protein, and gross energy compared to the control (p < 0.05). Third, intestinal responses aligned with localized gut modulation: both supplemented groups had higher culture-based Lactobacillus counts and lower E. coli counts in the cecum and ileum (p < 0.05), and T1 increased duodenal villus height (p < 0.05). In contrast, serum biochemical, immune, and antioxidant indices showed only isolated, phase-dependent changes and were not considered the primary response. Overall, moderate dietary supplementation with L. acidophilus enhanced nutrient utilization during mid-growth and was linked to targeted intestinal bacterial and morphological changes, but it did not consistently improve growth performance in yellow-feathered broilers.