Yingying Song

Anaerobic biodegradation is the most affordable method for the degradation of N,N-dimethylformamide. However, the degradation efficiency depends on the concentration. To elucidate the responses of microbial community to N,N-dimethylformamide load, microbial diversity, composition and functional changes at different concentrations of 100, 2000, and 3500 mg/L were analyzed. Results showed that as the N,N-dimethylformamide influent concentration increased from 100 to 2000 mg/L, the removal rate stabilized at 90%, whereas it decreased to ~75% at concentrations over 2000 mg/L. Microbial community diversity increased, and specialists were enriched at 3500 mg/L. Patescibacteria (42.88% and 42.90%), Bacillota (18.52% and 18.54%), and Pseudomonadota (7.13% and 7.09%) were the dominant phyla at 100 mg/L and 2000 mg/L, respectively, and Patescibacteria (16.88%) and Pseudomonadota (15.34%) were the dominant phyla at 3500 mg/L. Methylotrophic methanogeneic (Methanolobus and Methanomassiliicoccus) and syntrophic electron-donating bacteria (Clostridium and Trichococcus) were significantly enriched. DMF-degrading genes (fdh, rfA/nrfH, and ATPase) and methylotrophic methanogenesis genes (mcr, mta, and mtm) were significantly upregulated. Therefore, the degradation of N,N-dimethylformamide was characterized by a parallel carbon flux distribution, “methylamine-driven methanogenesis + further oxidation/integration of single-carbon intermediates”, and the nitrogen flux tended to enter a reductive nitrogen cycle characterized by retention and reuse.

Semen persicae is the dried mature seeds of Prunus persica (L.) Batsch and P. davidiana (Carr.) Franch and is commonly used in traditional Chinese medicine (TCM) formulations because of its variety of biological effects. The present study aimed to evaluate the antioxidant activity and toxicity profiles of semen persicae extract (SPE) after determining the amygdalin content (4.95%) using HPLC. Regarding the in vitro antioxidant activity, SPE with 2 mg/mL concentration scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and ABTS free radicals with rates of 51.78%, 55.47%, and 57.16%, respectively. The same concentration of SPE chelated 30.76% Fe²⁺. The in vitro cytotoxicity study revealed that SPE induced 92.45% cell viabilities of HEPG2 even at 2000 μg/mL. In the acute toxicity study, oral administration of SPE did not provoke mortality or any toxic signs at doses up to 2000 mg/kg bw. Repeated oral administration for 28 days at doses of 100, 300, and 600 mg/kg per day in rats did not show any toxicity signs or gross pathological abnormalities. The results of the present research provide basic reference data for SPE with a moderate effect on antioxidant activity and low toxicity for future screening of biological and pharmacological properties.