Project description:Previously, we performed DNA array-based transcriptomic analysis of Clostridium acetobutylicum biofilm adsorbed onto fibrous matrix in batch fermentation. Here, to further shed light on the transcriptomic modulation of maturing Clostridium acetobutylicum biofilm, we performed the DNA array-based transcriptomic analysis in repeated-batch fermentation. Significant time course changes in expression levels were observed for the genes involved in amino acid metabolism, oligopeptide ABC transporter, nitrogen fixation, and various other processes.
Project description:<p>Oxidative stress is a key inducer of chronic diseases, and apple polyphenols exhibit significant antioxidant potential. This study systematically analyzed polyphenol accumulation characteristics and antioxidant activity of four apple cultivars (Qincui, Jiuyue Qiji, Orin, Ruixue) using a multi-level system of traditional biochemistry, cell experiments, and untargeted metabolomics. Results showed Ruixue had the highest soluble solids, soluble sugar, total phenol contents, and DPPH scavenging activity, while Jiuyue Qiji was rich in total flavonoids. Apple polyphenols alleviated D-gal-induced BV2 cell senescence, with Ruixue and Jiuyue Qiji showing the strongest protective effects. Metabolomics identified 207 polyphenols, and 87 core active polyphenols significantly correlated with antioxidant activity were screened. Ruixue exhibited distinct polyphenol enrichment. This study clarifies cultivar-specific polyphenol accumulation and core active components, providing theoretical basis for high-antioxidant apple breeding and functional product development.</p>