Identification and characterization of Achromobacter spanius P-9 and elucidation of its deoxynivalenol-degrading potential.

Deoxynivalenol (DON) poses significant challenges due to its frequent contamination of grains and associated products. Microbial strategies for mitigating DON toxicity showed application potential. Eight bacterial isolates with DON degradation activity over 5% were obtained from various samples of organic fertilizer in this study. One of the isolates emerged as a standout, demonstrating a substantial degradation capability, achieving a 99.21% reduction in DON levels. This isolate, underwent thorough morphological, biochemical, and molecular characterization to confirm its identity, and was identified as a new strain of Achromobacter spanius P-9. Subsequent evaluations revealed that the strain P-9 retains its degradation activity after a 24-h incubation, reaching optimal performance at 35 °C with a pH of 8.0. Further studies indicated that Ca2+ ions enhance the degradation process, whereas Zn2+ ions exert an inhibitory effect. This is the pioneering report of DON degradation by Achromobacter spanius, illuminating its prospective utility in addressing DON contamination challenges.

Determination of Polycyclic Aromatic Hydrocarbons in Traditional Chinese Medicine Raw Material, Extracts, and Health Food Products.

The four polycyclic aromatic hydrocarbon markers (PAH4) of benzo[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF), and benzo[a]pyrene (BaP) are indicators showing polycyclic aromatic hydrocarbon (PAH) contamination levels in Chinese medicine raw materials (CMRMs), extracts and health food products; Samples of herbal medicine, herbal extracts, and food supplements were extracted with n-hexane, then cleaned up sequentially on Florisil and EUPAH solid-phase extraction (SPE) columns. A gas chromatography-mass spectrometry method for the determination of four polycyclic aromatic hydrocarbon markers in Chinese medicine raw material, extracts, and health food products was established; In spiked-recovery experiments, the average recovery was about 78.6-107.6% with a precision of 2.3-10.5%. The limit of quantification (LOQ) and limit of detection (LOD) of the PAH4 markers in this method were 2.0 µg/kg and 0.7 µg/kg, respectively. When the developed method was utilized to determine PAH4 contents in 12 locally available health food products, 3 samples contained over 10.0 µg/kg BaP, and 5 samples contained over 50.0 µg/kg PAH4. The European Union (EU) limits for BaP and PAH4 are 10 and 50.0 µg/kg, respectively; therefore, more attention must be drawn to the exposure risk of BaP and PAH4 in CMRMs, their extracts, and health food products. According to the risk assessment based on the Margin of Exposure (MOE) method, it is recognized that the products mentioned in this study pose a low risk.

Extraction and Study of Hypoglycemic Constituents from Myrica rubra Pomace.

Myrica rubra pomace accounts for 20% of the fruit's weight that is not utilized when it is juiced. The pomace contains bioactive phenolic substances such as anthocyanins and flavonoids. To improve the utilization value of Myrica rubra pomace, an optimized extraction method for the residual polyphenols was developed using response surface methodology (RSM). The resulting extract was analyzed by high performance liquid chromatography (HPLC), and the in vitro hypoglycemic activity and antioxidant activity of the polyphenolic compounds obtained were also investigated. The optimum extraction conditions (yielding 24.37 mg·g-1 total polyphenols content) were: extraction temperature 60 °C, ultrasonic power 270 W, ethanol concentration 53%, extraction time 57 min, and solid to liquid ratio 1:34. Four polyphenolic compounds were identified in the pomace extract by HPLC: myricitrin, cyanidin-O-glucoside, hyperoside, and quercitrin. DPPH and hydroxyl radical scavenging tests showed that the Myrica rubra polyphenols extract had strong antioxidant abilities. It is evident that the residual polyphenols present in Myrica rubra pomace have strong hypoglycemic activity and the juiced fruits can be further exploited for medicinal purposes.

Biodegradation Characteristics and Mechanism of Aflatoxin B1 by Bacillus amyloliquefaciens from Enzymatic and Multiomics Perspectives.

Aflatoxin B1 (AFB1), a mycotoxin and natural carcinogen, commonly contaminates cereals and animal feeds, posing serious health risks to human and animal. In this study, Bacillus amyloliquefaciens ZG08 isolated from kimchi could effectively remove 80.93% of AFB1 within 72 h at 37 °C and pH 7.0. Metabolome and transcriptome analysis showed that metabolic processes including glycerophospholipid metabolism and amino acid metabolism were most affected in B. amyloliquefaciens ZG08 exposed to AFB1. The adaptation mechanism likely involved activation of the thioredoxin system to restore intracellular redox equilibrium. The key genes, tpx and gldA, overexpressed in Escherichia coli BL21, achieved degradation rates of 60.15% and 47.16% for 100 µg/kg AFB1 under optimal conditions of 37 °C and pH 8.0 and 45 °C and pH 7.0, respectively. The degradation products, identified as AFD1, were less cytotoxic than AFB1 in HepG2 cells. These findings suggest potential strategies for utilizing probiotics and engineered enzymes in AFB1 detoxification.

Transcriptome Analysis of Deoxynivalenol (DON)-Induced Hepatic and Intestinal Toxicity in Zebrafish: Insights into Gene Expression and Potential Detoxification Pathways.

The effects of deoxynivalenol (DON, 50 µg/mL) on the zebrafish liver and intestine were studied. Differentially expressed genes (DEGs) from mRNA and lncRNA were analyzed by RNA seq. Gene Ontology (GO) and signaling pathways were studied where the top 30 DEGs of each type of RNA were involved. The results showed there were 2325 up-regulated and 934 down-regulated DEGs of lncRNA in the intestinal tract, and 95 up-regulated genes and 211 down-regulated genes in the liver, respectively. GO functional annotation analysis showed that lncRNA was enriched in the biological processes, involving the RNA splicing, CSF1-CSF1R complexes, and MAP kinase activity. DEGs of lncRNA located in the KEGG signal pathways include the C-type lectin receptor signaling and the NOD-like receptor signaling pathways. Metabolism involves the biosynthesis of indole alkaloids, cancer pathways for human disease, MAPK and Rap1signaling pathways for environmental information processing, necroptosis and focal adhesion for cell processes. The mRNA gene expression analysis showed there were 1939 up-regulated, 1172 down-regulated genes and 866 up-regulated, 1211 down-regulated genes in the intestine and liver of zebrafish, respectively. This study provides transcriptome analysis and toxicological investigation of DON in the zebrafish liver and intestine, offering insights into gene expression patterns and potential detoxification pathways.