Fermentation technology was used to improve the antioxidant activities of Auricularia auricula polysaccharide (AAP). Response surface methodology (RSM) was used to optimize the fermentation conditions. The effects of 4 independent factors: water content (X1: 40-80%), inoculation amount (X2: 2-20%), temperature (X3: 24-32 °C), and time (X4: 4-6 d) on the biological degradation efficiency were evaluated. The RSM results showed that the optimal fermentation conditions were: X1: 61.7%, X2: 12.4%, X3: 31.0 °C, X4: 5.5 d. Verification tests showed no significant differences between the practical and the predictive values for each response. Under the optimal conditions, the degradation rate was 26.89 ± 0.14%, without significant differences with the predicted value (27.03%). The degradation products were classified to different molecular weight (Mw) polysaccharide fragments using membrane separation technology. The FT-IR analysis and monosaccharide composition analysis of degraded AAP (D-AAP-VI) showed that D-AAP-VI was a furan type polysaccharide, which was different from the total AAP (pyran type). In addition, compared to total AAP, the antioxidant activities in vitro of D-AAP-VI were significantly improved (p < 0.05) and D-AAP-VI showed the strongest antioxidant activity. These results indicated that biological degradation may be a suitable way to improve the antioxidant activities of natural polysaccharides.

中文翻译：

---

响应面方法用于使用木霉属木霉发酵金耳木耳多糖的发酵及其抗氧化活性。

发酵技术被用来提高木耳多糖（AAP）的抗氧化活性。响应面法（RSM）用于优化发酵条件。4个独立因素的影响：含水量（X1：40-80％），接种量（X2：2-20％），温度（X3：24-32°C）和时间（X4：4-6 d）对生物降解效率进行了评估。RSM结果表明最佳发酵条件为：X1：61.7％，X2：12.4％，X3：31.0℃，X4：5.5d。验证测试表明，每种响应的实际值和预测值之间没有显着差异。在最佳条件下，降解率为26.89±0.14％，与预测值（27.03％）无显着差异。使用膜分离技术将降解产物分类为不同分子量（Mw）的多糖片段。降解AAP（D-AAP-VI）的FT-IR分析和单糖组成分析表明，D-AAP-VI是呋喃型多糖，与总AAP（吡喃型）不同。此外，与总AAP相比，D-AAP-VI的体外抗氧化活性显着提高（p <0.05），D-AAP-VI表现出最强的抗氧化活性。这些结果表明，生物降解可能是改善天然多糖抗氧化活性的合适方法。这与总AAP（吡喃型）不同。此外，与总AAP相比，D-AAP-VI的体外抗氧化活性显着提高（p <0.05），D-AAP-VI表现出最强的抗氧化活性。这些结果表明，生物降解可能是改善天然多糖抗氧化活性的合适方法。这与总AAP（吡喃型）不同。此外，与总AAP相比，D-AAP-VI的体外抗氧化活性显着提高（p <0.05），D-AAP-VI表现出最强的抗氧化活性。这些结果表明，生物降解可能是改善天然多糖抗氧化活性的合适方法。