用酵母菌Pichia holstii醱酵生產胞外多醣的最適化

Optimization of Exopolysaccharide Production by Submerged Culture of Pichia holstii

呂世淵(Shih-yuan Lu)

指導教授 ： 許垤棊

大同大學/工程學院/生物工程學系所/碩士(2005年)

摘要

硫化寡醣在臨床上具有抗凝血、抗病毒以及抗腫瘤的潛力。酵母菌的細胞外多醣可以當作硫化寡醣的原料，因而受到格外的重視。本研究主要是利用酵母菌Pichia holstii BCRC 22637，於五公升醱酵槽中，在不同培養基的條件下，探討產生細胞外多醣的最適化。醱酵條件包括：不同葡萄糖濃度、磷酸鉀濃度與不同氮源的濃度，以得到生產細胞外多醣的最大產量。醱酵槽操作條件為轉速450 rpm，通氣量2 L min-1，溫度維持在25℃，pH控制在5.0 ± 0.3之間。經過醱酵120小時後，發現培養基中葡萄糖的濃度為200 g L1 ；磷酸鉀濃度為15 g L1以及corn steep liquor 4 g L-1 和yeast extract 4 g L-1時，細胞外多醣的乾重高達72.4 g L1，而菌體量乾重達20.7 g L1。

關鍵字

酵母菌、細胞外多醣、批次醱酵

並列摘要

Yeast exopolysaccharide (EPS) has been becoming attractive, because it can serve as raw material for the manufacture of sulfated oligosaccharide, which was currently under clinical evaluation as anticoagulant, anti-virus and anti-tumor agent. In the present study, batch cultures of Pichia holstii BCRC 22637 for EPS production under different conditions at various concentrations of glucose and potassium dihydrogen phosphate with various concentrations of different nitrogen sources were investigated. The fermentation medium consisted of the following ingredients in gram per liter: MgSO4.7H2O, 0.2; MnSO4.H2O, 0.01; FeSO4.7H2O, 0.01 and NaCl, 0.01. Fermentation was carried out under the following conditions: initial working volume 2 L, agitation 450 rpm, aeration 2 vvm, temperature 25℃ and pH controlled at 5.0 ± 0.3. For the optimal production of EPS the medium consisted of the following ingredients in gram per liter: glucose 200, corn steep liquor 4, yeast extract 4 and KH2PO4 15. After an 120-h fermentation, up to 72.4 g L-1 EPS and 20.7g L-1 cells, on a dry weight basis, were obtained.

並列關鍵字

batch fermentation ； exopolysaccharide ； Pichia holstii

參考文獻

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