【摘要】 菌株T4是从哈尔滨市农业科学院试验田表层土壤（125°42′E,44°04′N）筛选的耐紫外辐射芽孢杆菌。通过UV_{254 nm}处理菌株T4,对比其胞内多糖产量的变化，随后对胞内多糖进行提取、分离和纯化，并测定纯化组分（IPS-1和IPS-2）的分子量、单糖组成及抗氧化活性（以DPPH自由基清除率、超氧阴离子自由基清除率、总还原力为指标）。结果显示，经UV_{254 nm}照射后，菌株T4胞内多糖产量从（5.71±0.16） mg·L^-1显著提升至（7.45±0.31） mg·L^-1;纯化得到的IPS-1（分子量8.05×10⁴ Da）由29.75%甘露糖、26.45%葡萄糖、36.92%木糖及6.89%阿拉伯糖组成，IPS-2（分子量2.90×10³ Da）由54.08%甘露糖、20.69%木糖及25.22%阿拉伯糖组成；IPS-1与IPS-2均具抗氧化活性，且IPS-1活性更优。本研究明确了UV_{254 nm}对菌株T4胞内多糖积累的促进作用，完成了多糖表征与活性分析，为其后续生产提供了依据。更多还原

【Abstract】 Strain T4 is a UV-resistant Bacillus strain isolated from the surface soil（125°42′E, 44°04′N） of the experimental field at Harbin Academy of Agricultural Sciences. Strain T4 was treated with UV_{254 nm}, and the changes in its intracellular polysaccharide yield were compared. Subsequently, the intracellular polysaccharides were extracted, separated and purified, and the molecular weight, monosaccharide composition and antioxidant activity of the purified fractions（IPS-1 and IPS-2） were determined, with DPPH free radical scavenging rate, superoxide anion free radical scavenging rate and total reducing power as indicators. The results showed that after UV_{254 nm} stimulation, the intracellular polysaccharide yield of strain T4 significantly increases from（5.71±0.16） mg·L^-1 to（7.45±0.31） mg·L^-1. The purified IPS-1（molecular weight: 8.05×10⁴ Da） is composed of 29.75% mannose, 26.45% glucose, 36.92% xylose and 6.89% arabinose, while IPS-2（molecular weight: 2.90×10³ Da） is composed of 54.08% mannose, 20.69% xylose and 25.22% arabinose. Both IPS-1 and IPS-2 have antioxidant activity, and the activity of IPS-1 is better. This study clarifies the promoting effect of UV_{254 nm} on the intracellular polysaccharide accumulation of strain T4, completes the characterization and antioxidant activity analysis of the polysaccharides, and provides a basis for their subsequent production.更多还原