This study aimed to isolate and evaluate a novel cellulolytic probiotic strain from the intestinal contents of yaks on the Qinghai–Tibet Plateau. A strain identified as Enterococcus faecalis JM263 exhibited strong cellulolytic activity, with CMCase, FPase, and β-glucosidase activities reaching 29.5, 23.58, and 15.62 U/mL, respectively. It exhibited strong tolerance to simulated gastric (75.3%) and intestinal (68.5%) fluids, dose-dependent bile salt resistance, and broad-spectrum antimicrobial activity—most notably, a 21.27-mm inhibition zone against Salmonella. Additionally, E. faecalis JM263 scavenged DPPH and hydroxyl radicals at rates of 41.05% and 36.54%, respectively. Additionally, E. faecalis JM263 exhibited strong degradation abilities toward cellulose, lignin, and hemicellulose in both corn straw and oatgrass. In vitro rumen fermentation experiments revealed that E. faecalis JM263 significantly increased acetate and VFAs while reducing ammonia-N levels. 16S rRNA sequencing revealed that E. faecalis JM263 altered the rumen microbial composition by increasing the abundance of beneficial taxa such as Fibrobacterota, Prevotella, and Succinivibrio. Functional prediction via PICRUSt and COG annotation suggested that E. faecalis JM263 supplementation may enhance microbial metabolism, particularly pathways involved in carbohydrate metabolism, amino acid biosynthesis, and energy production. Additionally, E. faecalis JM263 was shown to promote cooperative interactions among functional microbes, contributing to a more efficient and stable rumen microbial ecosystem. Overall, E. faecalis JM263 is a promising candidate functional probiotic for improving fiber digestibility and rumen fermentation efficiency in ruminants, offering great potential for application in sustainable animal production.
Enterococcus faecalis is the main cause of refractory root canal infections in human teeth. The control of root canal infection is one of the conditions necessary for the successful treatment of refractory root canal infections. In the present study, nano-scale silver–zinc–calcium–silica particles loaded with different ratios of silver–zinc were successfully prepared (Ag0.5Zn3-MCSNs and Ag0.5Zn10-MCSNs). The release profiles, antibacterial activity against E. faecalis, infiltration depth into dentinal tubules, biocompatibility and effects on dentin microhardness in vitro were investigated. In addition, the antimicrobial effects of the particles against Enterococcus faecalis reinfection were evaluated in vivo in the teeth of beagle dogs. Ag, Zn, Ca and Si were released from Ag–Zn-MCSNs, and the atomic ratio of silver and zinc released can reach the optimal value of 1 : 12 (Ag0.5Zn10-MCSNs). The particles also showed good biocompatibility and antibacterial activity against Enterococcus faecalis and did not reduce the hardness of dentin. The nanoparticles could be driven into the dentinal tubules of dentin slices by ultrasonic activation. In the root canals of beagle dogs, both Ag0.5Zn3-MCSNs and Ag0.5Zn10-MCSNs demonstrated strong preventive effects against E. faecalis infection. The Ag–Zn–Ca–Si mesoporous nanoparticles may develop into a new effective root canal disinfectant or root canal sealer.
危险品化学品经营许可证（带存储）