以Indole-3-acetic acid為指標生產具有抗發炎活性的玉米黑穗菌發酵液

Abstract

玉米黑穗菌是一種寄生在玉米上的寄生菌，在玉米上生成膨大的腫瘤組織，在墨西哥當地被視為一種傳統美食。研究指出，此菌會代謝色胺酸，生成如indole-3-acetic acid(IAA)以及pityriarubin類化合物，其分別在動物實驗和細胞實驗上證實具有抗發炎效果。因此，本研究即期望利用此菌，以IAA為指標，使用攪拌式發酵槽生產具有抗發炎活性的玉米黑穗菌發酵液。經過一系列的最適化研究，結果發現在培養溫度24 ℃、起始pH 4、培養基組成為含有1 g/L色胺酸的PDB培養基額外添加20 g/L葡萄糖、扇葉攪拌速率900 rpm、通氣量0.5 vvm的條件下，經過32小時的發酵時間，可生產出含有30.8±4.5 μg/ml IAA (HPLC定量)的玉米黑穗菌發酵液，並以RAW264.7細胞模式證明此發酵液在10%的添加量下，其抑制發炎因子NO的比例達81.0±0.3%。

Ustilago maydis is a pathogen infecting on corn and induces tumor tissue formation. Althoug it is a pathogen, it is seen as a traditional cusine in Mexico. It can metabolize trytophan into indole-3-acetic acid (IAA) and pityriarubin with anti-inflammation bioactivity. Therefore, the goal of this research was to produce fermentation broth of Ustilago maydis possessing anti-inflammation function using indole-3-acetic acid as marker in a 5 L stirred tank fermentor. After optimization process, it was found that the fermentation process would produce 30.8±4.5 μg/ml IAA in the broth using PDB medium supplemented with 1g/L tryptophan and 20 g/L glucose with initial pH at 4. The optimal fermentation conditions in the stirred tank bioreactor are: agitation rate at 900 rpm; aeration rate at 0.5 vvm, and 24℃ for 32 h. Moreover, the broth (10%) can inhibit nitrite production up to 81.0±0.3% in RAW264.7 inflammation cell model.