Fusobacterium nucleatum ( F. nucleatum ) is an early pathogenic colonizer in periodontitis, but the host response to infection with this pathogen remains unclear. In this study, we built an F. nucleatum infectious model with human periodontal ligament stem cells (PDLSCs) and showed that F. nucleatum could inhibit proliferation, and facilitate apoptosis, ferroptosis, and inflammatory cytokine production in a dose-dependent manner. The F. nucleatum adhesin FadA acted as a proinflammatory virulence factor and increased the expression of interleukin(IL)-1β, IL-6 and IL-8. Further study showed that FadA could bind with PEBP1 to activate the Raf1-MAPK and IKK-NF-κB signaling pathways. Time-course RNA-sequencing analyses showed the cascade of gene activation process in PDLSCs with increasing durations of F. nucleatum infection. NFκB1 and NFκB2 upregulated after 3 h of F. nucleatum -infection, and the inflammatory-related genes in the NF-κB signaling pathway were serially elevated with time. Using computational drug repositioning analysis, we predicted and validated that two potential drugs (piperlongumine and fisetin) could attenuate the negative effects of F. nucleatum -infection. Collectively, this study unveils the potential pathogenic mechanisms of F. nucleatum and the host inflammatory response at the early stage of F. nucleatum infection.
Fermented soybean products are an integral part of the Chinese diet, valued for their distinctive aroma. Bacillus subtilis ( B. subtilis ) BJ3-2 is a highly effective fermentation strain widely used in the industrial production of bacterial-type douchi. However, the specific aroma characteristics of soybeans fermented by this strain remain unclear. This study utilized gene knockout, GC-O-MS, and multivariate statistical analysis to comprehensively investigate the aroma components of soybeans fermented by B. subtilis BJ3-2. For the first time, 12 key aroma skeleton compounds were identified, including guaiacol, 2,5-dimethylpyrazine, and 2-methylbutyric acid, which primarily contribute to the smoky, roasted, and sweaty aroma attributes of fermented soybeans. Additionally, 17 compounds were considered to have important coordinating effects on soybean aroma, such as 3-hydroxy-2-butanone (buttery, creamy). Partial least squares regression (PLSR) analysis demonstrated a good correlation between key aroma compounds and sensory attributes. Gene knockout of fadA and bkdB resulted in a significant increase in 2,5-dimethylpyrazine and 1-octen-3-ol levels, along with a marked reduction in 2-methylbutyric acid levels. These changes enhanced the roasted and beany notes, reduced the sweaty aroma, and ultimately improved the overall aroma profile. These findings provide insights into the genetic regulation of aroma in fermented soybean products and form a foundation for reducing undesirable aromas and improving the overall aroma quality of industrially produced douchi. Bacillus subtilis fermented soy food is deeply loved by consumers, and its unique aroma characteristics are influenced by the fadA and bkdB genes.
危险品化学品经营许可证（带存储）